FULLY SERVICED / RESTORED W/ WARRANTY*
VINTAGE STEREO RECEIVERS
SERVICED / RESTORED CLASSICS 

 

(*UNLESS OTHERWISE LISTED)
 

SERVICED / REFURBISHED / RESTORED
CLASSIC STEREO RECEIVERS. . .
    

 

       

     

            NEW LISTING 11/19/2022
(click on above thumbnails to enlarge photos)
  warranty  
RESTORED / REFURBISHED / FULLY SERVICED
STEREO / QUADRAPHONIC
RESTORED / REFURBISHED / FULLY SERVICED
VINTAGE STEREO RECEIVER SANSUI QUADRAPHONIC / 4-CHANNEL / 2-CHANNEL STEREO RECEIVER
SANSUI QRX-8001RECEIVER
#...0253
Circa 1976-77
"WORLD AC POWER" ™
 M.I.J.
for sale

ü Our technician has EXTENSIVELY gone through and 'Certified' this unit.

ü  We have completely gone through this unit cleaning everything including all switches, controls and contacts. Extensive cleaning of unit internally.



ü Internal fuses checked for continuity and correct values. No issues found, fortunately. We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.

ü Controls were 'flooded' w/ 'De-OxId' and are quiet

ü Tuner string checked for any fraying then re-tensioned to increase traction & relieve flywheel binding and re-centered pointer to correct dial position.

ü  We aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. VERY GOOD TUNER! AM seems to be an 'afterthought' on many stereo receivers and component tuners. The AM is above average for a 'stereo receiver' on this SANSUI QRX-8001. 

ü All dial, indicator & meter lamps tested working and found to be low current, cool running units.

ü We also checked the heat sink compound which should be good for many more years.

ü Amplifier section had output bias adjusted to spec levels of 30mA ±3mA on all four amplifiers.

ü  DC offset adjusted to VERY LOW levels of 3mVDC L and 2-3mVDC R.

ü All inputs tested and both side produces clean and even sine waves into 'brick-wall' 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.
Total restoration time investment 12 hours.

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 72 hours into a 4 ohm load.
 
On our test bench, this particular QRX-8001, #...0253, 'FRONT' & 'REAR' amplifiers each produced 22 Volts per channel for 60 Watts per channel @ 8Ω via discrete output & 18 Volts per channel for 81 Watts per channel @ 4Ω via discrete, Metal cased, TO-3 outputs.
(AC draw at idle .5A tested.
DC Offset set to 3mVDC or less
Floor noise measured at -54dB
 ___________________________
 
HUGE and VERY IMPRESSIVE looking, Sansui, brushed silver, QUAD receiver, surrounded by handsome, real Walnut wood veneer side plates. This unit has about THE highest 'KPD-Factor' of any receiver every made. What's a 'KPD Factor'? 'Knobs per Dollar! You could also say it has very high 'MPD' and 'LPD' factors as well (you should be able to figure those out now). Features gorgeous, back-lit slide rule analog tuning scale with matching VU meters as well. VERY elegant and IMPRESSIVE unit when lit in a darkened room. 'Heavy' built, machined aluminum knobs and button caps, also make this unit a pleasure to 'feel'. One of the most 'fun' receivers I've used in a long time. Would love to abscond with this one myself.
Sansui QRX-8001 Features include:
  
- Quadraphonic (sometimes spelled "quadriphonic" or "quadrophonic") / Stereo receiver 
- Weighted flywheel analog tuning
- Huge, externally located heat-sinks on the rear panel (keeps the heat production from the outputs on the outside of the unit. ALL units should be designed this way)
- A, B, Off or A+B Front and Rear speaker positions
- Separate Front and Rear, Bass and Treble controls
- Balance controls allow complete blending between Front and Rear / Left and Right
- Built-in Hi and Sub filters (separately switch-able Front and Rear) for reducing 19KHz pilot tone in FM broadcasts, Tape Hiss and the Sub filter for reducing turntable rumble and to keep un-necessary low freqs out of speakers)
- FM muting
- FM Stereo (separate from "Pre-Amp Stereo")
- ''Function Control' selector for 2-Channel Stereo, & 4-Channel modes of ''QS Synthesizer' (To convert (synthesize) conventional, 2-channel / stereo program sources to 4-Channel stereo output), 'QS Regular Matrix' (to decode and reproduce 4-channel program sources (records, tapes and their respective broadcasts), ''Phase Matrix' (to decode and reproduce 4-channel program sources, encoded with the CBS / SQ matrix system) or 'CD-4 / Discrete' (when wishing to hear discrete 4-channel tapes or CD-4 (Quadradisc) records).
- Aux inputs for both Front and Rear (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS®  etc.)
- Dual tape monitors with Tape monitor A also featuring a DIN input as well as the standard RCA I/O's for both Front and Rear
  (Tape Monitors can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Phono / Turntable input with Built-In Phono Pre-Amp, compatible with 'CD-4' cartridges
- Microphone input (be careful with 'home audio speakers' and open microphones)
- Loudness control for increasing 'rock-n-roll smile' tone curve at lower volumes
- Front and Rear 1/4" stereo headphone jacks for connection of either 'stereo' headphones, or 'quadraphonic / 4-channel' headphones
- -20dB Instant Audio Muting switch
- Tuning D’Arsonval meters for tuning and signal strength
- Quad VU meters for channel output power levels
-'CD-4' Level adjustments located on front panel for Carrier Level, and L/R Separation of Quad discs / records.
- Built-in AM 'Stick' antenna on swivel mounting bracket
- Rear located, full barrier strip for external antenna connections
- Rear located main AC protection fuse
- Dual AC convenience outlets on rear panel with 1 switched and 1 un-switched for a total capacity of 250 Watts of accessories
  - True “WORLD AC POWER"™
   as it will work on both 50 or 60 Hz AC and voltages from 110-240 Volts AC

Sansui QRX-8001 Original Specs:

 POWER / PRE AMP SPECIFICATIONS:
THD; 0.3% @ full rated power @ 1KHz.
 Power bandwidth of power amp section; 20-20,000Hz ±0dB
 IMD utilizing AUX;
 0.3% @ full rated power / 20-20KHz and 8 Ohms
 Damping factor; 30 @ 8Ω full bandwidth
Dynamic rated Power: 2 x 100 Watts @ 8 Ohms (in "2X" mode and ONLY 8 Ohms)
Cont rated Power:
4x 40 Watts @ 8 Ohms / 20-20,000Hz (ALL channels driven)
4x 40 Watts @ 4 Ohms / 20-20,000Hz (ALL channels driven)

Hum and Noise; >80dB on AUX / Tape
Input Sensitivity AUX / Tape; 100mV @ 50kΩ
Input Sensitivity Mic; 4mV @ 10kΩ
Record Out Levels; 100mV RCA's
Bass Control;  ±10dB @ 50Hz
Treble Control;  ±10dB @ 10KHz
Low Filter;  -10dB @ 50Hz @ 6dB Oct
High Filter;  -10dB @ 10KHz @ 6dB Oct
"Loudness" Contour;  +8dB @ 50Hz, +3dB @ 10KHz (w/ volume set at -30dB)

TUNER SPECS FOR FM:
Tuning Range; 88-108MHz
Freq Response; 30-15KHz (limited by FCC)
S/N; > 60db Stereo w/ 1mV input
> 65db Mono w/ 1mV input
Stereo Sensitivity; 45μV
Mono Sensitivity; 3.5μV
Capture Ratio; <2.2dB
IF Response Ratio; >75dB
Image Response Ratio; >50dB
Spurious Noise Ratio; >70dB
Selectivity; >60dB
THD w/ 100% modulation Mono; 0.4%
THD w/ 100% modulation Stereo; 0.5%
Stereo Separation; >40dB @ 1KHz

TUNER SPECS FOR AM:
Tuning Range; 535-1605KHz
Useable Sensitivity; 50db/m with ferrite stick antenna
Image Response Ratio; >35dB
Selectivity; 35dB

PHONO SECTION SPECS:
Freq Response; 30-15KHz RIAA Standard Curve +/- 1dB.
S/N; >70 dB
Input Sensitivity; 2.5 mV @ 50kΩ
Overload limit; 150mV w/ 0.3% THD @ 1KHz

CD-4 DEMODULATOR:
Input Sensitivity; 2.5mV
Input Impedance; 50kΩ
Freq Response (STD test signal); Main Channel 30-15KHz, Sub Channel 30-10KHz
Power consumption; 550 Watts at max
  
Again, as stated before, we have completely gone through this SANSUI QRX-8001 Quad receiver, cleaning and testing all and it gets our full 'Certification'. Everything is in fabulous electrical and cosmetic condition! Looks and sounds great! AMAZING looking when lit up at night or in a darkened room! Again, this unit is a 'blast' to use. It just simply 'feels nice'!
Comes with an 'e-copy / PDF download of the SANSUI QRX-8001 owners / users manual, and the service manual if the purchaser desires.  Measures 23.75" wide x 7" tall x 16.5" deep and weighs an impressive 52 lbs unpacked. Includes our standard 30 day limited warranty.
SANSUI QRX-8001 STEREO RECEIVER
Cond. 8.5++
$1999. (C)
M.S.

(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)
 
 

   

         NEW LISTING 12/17/2021
(click on above thumbnails to enlarge photos)
warranty
FULLY SERVICED / REFURBISHED / WARRANTED
ONE OWNER!
VINTAGE REALISTIC STEREO RECEIVER
 REALISTIC  STA-2000 / STA2000
"BIG POWER OUTPUT!"
Orig Cat #31-2075
#...9602
CIRCA 1978
for sale

Original Cond; "Very clean / kept well. Powers up. Lights up. No relay click, due to 32+VDC on one side of outputs thus unable to test further."

ü Our technician has EXTENSIVELY gone through and 'Certified' this unit.

ü Amp has been cleaned inside and out. All internal control pots and switches are super quality.

ü All 6 Internal fuses checked for continuity / values and all were correct values fortunately. (We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.)

ü Checked power supply board for correct Voltages.

ü Output transistors removed and tested independently

ü Replaced electrolytic capacitors on driver board  (all not included in above photo)  

ü Replaced transistors, TR512, TR508, TR516 & resistor R520 on driver board to rectify high DC out issue (all not included in above photo).

ü Output transistors replaced with fresh heat-sink compound

ü DC offset adjusted to VERY LOW levels on either amplifier, and well below 'spec' levels (check results below).

ü Bias set to spec @ 17.5mVDC across emitter resistors. Nice, even sine waves to both rails up to 26.5VAC.

ü All Dial / Meter  / function / stereo indicator lamps (eleven in all) replaced for trouble free service (1x #25-090, 4x #280, 6x #25-160). (all not included in above photo)  

ü We also aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. The tuner works exceptionally well in our warehouse. Picks up both AM and FM bands way above average!!!

ü All inputs tested and both side produces clean and even sine waves! No power supply hum of any kind. It's dead silent! All functions test fine. 

ü Entire unit cosmetically detailed in and out

ü Real, Walnut wood veneer side panels had fresh coat of Lemon oil and look great.

ü Total Tech time investment ~32 hours. OUCH! (mostly because of the R driver board)
      
 While this unit was originally rated at 75 Wpc, on our test bench, this particular unit, #...9602's amplifiers produced 26.5 Volts per channel at 8 Ohms for 87 Watts per channel & 22 Volts at 4 Ohms for 121 Watts per channel via discrete, TO-3, metal-cased output devices. (NEC 2SB539A & 2SD287A) DC adjusted down to <5mV L&R. AC idle current draw .4A. Floor noise measured at <-74dBm.
    ____________________________
    
Up to 1978, this was the pinnacle of Realistic's offerings. The STA-2000. This one also features an exceptional tuner.

The Realistic STA-2000 is internally built with all the attention to detail and quality you hope to get in a 'vintage, Japanese-built' stereo amp. The, TO-3, Metal Cased output transistors are mounted in a large, heat-sink array, vertically oriented with ventilation located directly above and below. To back up the power output transistors is a HUGE power supply transformer,

(taken prior to bench work, thus the 'dust')

with giant 63V / 15,000 uF Filter capacitors. Also, the capacitors are NOT mounted to a circuit board, but are 'clamped' to the metal chassis and then connected via "point-to-point" wiring. All of the rotary potentiometers are quality, 'FULL SIZE' and are NOT mounted to a circuit board, but fastened to the metal chassis and then connected via "point-to-point" wiring (means that when you put pressure on a knob, you're not directly 'flexing / fatiguing' solder joints on the 'main circuit board' {YES, that happens and is commonly an issue with most gear}). High heat resistors 'stand proud' of the circuit boards, to keep avoid 'heat damage'. Speaker connector terminals are mounted separately (not to the 'main board'), are anchored completely to the rear chassis metal, with their own cb that is 'point-to-point' wired to the main circuit board. The RCA I/O jacks are mounted similarly. The benefit of that is that every time you connect / disconnect a Tape deck, Turntable, CD, DVD, MP-3 player, DAT, iPhone / Android or any other device to the unit, you aren't 'flexing / fatiguing' solder joints on the 'main circuit board'. 7-Gang tuning capacitor, has full shielding to reduce RFI with adjustment markings.
Of course, like most 'good' audio, it's circuit boards are built / populated with 'old school, discrete and 'full size' parts (capacitors, diodes, resistors and transistors) with NO, 'Low Wattage / Low current', 'SMD' components.
All the pots, controls and construction quality in general is way above average! It's built like a "brick $h17 house"
 
Realistic STA-2000 Features include:

- Discrete output transistors, featuring Metal Cased, TO-3 devices (best, most expensive way to build an amp)
- 7-Gang Tuning capacitor 
- Weighted flywheel analog "slide-rule" tuning with huge and heavy tuning knob and wide scale window
- Classic brushed Aluminum face panel
- Main & Remote speaker selectors
- Oversized volume control featuring high quality de-tented pot
- Separate Bass and Treble controls utilizing high quality de-tented pots that are also Left and Right independent
- Pre-Amp / Power Amp loop (allows Pre-amp to feed others systems / amplifiers or other pre-amps / mixers to feed power amp separately. This can be one of the handiest features of a receiver / integrated amplifier, and is typically only found on a brands 'mid-upper' to 'upper-end' models)
- FM Muting (separate from Stereo / Mono selector)
- Mono selector (for the entire pre-amp section, not just the tuner and separate from FM muting selector)
 - "Loudness" function to boost Bass in relationship to other frequencies at lower volume levels for a much fuller sound (careful using this as it's approx a 6dB boost!!!)
- Hi / MPX filter for reducing the 19KHz pilot tone and 38KHz harmonic in FM broadcasts
- Phono / Turntable input w/ built-in phono pre-amp
- -20dB Audio Muting
-  Dual AUX Inputs ((may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPad® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS®, external mixing board, etc.) )
- Dual Tape monitors with Bi-Directional Dubbing capability ("Tape-1" features both RCA and DIN I/O's)
    (Tape Monitors can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc) Dubbing can be used with CDR (CD recorders) units)
-  Dual back-lit, analog VU power meters
- Overload, Thermal and DC short protection built-in
- Analog 'Tuning' Meter for both AM and FM
- Front mounted 1/4" stereo headphone jack
- Speaker outputs via typical / standard "bare wire" push clips and redundant RCA type
 - Externally located main AC protection fuse as well as 5 internally located protection fuses for sub-systems
- Dual AC convenience outlets on rear panel with 1 switched and  un-switched totaling 200 Watts capacity
    
Realistic STA-2000 Original Specs:
Frequency Response: 15Hz to 20KHz ± 2dB
Signal/Noise ratio at AUX input: 75dB
Power Band Width: 20-20KHz
THD: <0.25% @ 75 Wpc
Power: 75 Watts per channel
  
PRE-AMP SECTION SPECS;
Freq Response; 20-20KHz
Bass Control Range; ± 10dB @ 100Hz
Treble Control Range; ± 10dB @ 10KHz
Loudness Compensation; + 6dB @ 100Hz
Cross Talk; 65dB
Tape Out Leval; 140mV
  
  
PHONO SECTION SPECS;
Freq Response; 20-20KHz
 S/N; 70 dB
Input Sensitivity; 2.2mV @ 50kΩ
Overload limit; 230mV
  
TUNER SPECS FOR FM;
Freq Response; 30-15KHz
S/N; > 70db Stereo
Mono Sensitivity; 1.7μV
Capture Ratio; 1.5dB
Image Rejection; 80dB
IF Rejection; 80dB
   
Again, we have completely gone through this Realistic STA-2000 Stereo Receiver, as stated above and 'certified' it's 'Ready To Go'! Real Walnut Wood veneer case in fabulous condition as is the milled aluminum face and all original knobs. Includes a pdf, 'e' copy, download of the Realistic STA-2000 owners / users / instruction manual.
 Fabulous performer. Again this receiver looks and sounds great! It's ready to go and ready to ROCK! Receiver measures 20.5" wide x 18" deep x 7" high and weighs 52 lbs unpacked. Includes our standard 30 day limited warranty.
REALISTIC STA-2000
Condition 8.5++
$1299.
 (C) R.R.
 
 
 (Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)
 

    

 

          NEW LISTING 11/19/2022
 (Click on above thumbnails to enlarge photos)
  warranty
RESTORED / REFURBISHED / FULLY SERVICED
VINTAGE TOSHIBA 8-TRACK / STEREO RECEIVER
TOSHIBA TMC-7550
Circa ~1977-1980
for sale

ü Our technician has EXTENSIVELY gone through and 'Certified' this unit.

ü We have completely gone through this unit cleaning everything including all switches, controls and contacts. VERY time consuming to properly service this unit, especially the 8-track deck. Extensive cleaning of unit internally.

ü Internal fuses checked for continuity and correct values. No issues found, fortunately. We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.

ü Controls were 'flooded' w/ 'De-OxId' and are quiet

ü Entire transport was cleaned and re-lubed as well as the always at issue, Pinch Roller plunge assembly, re-lubed and reassembled (VERY DIFFICULT and TIME CONSUMING)

ü Entire transport and tape path de-magnetized

ü Main drive belt has been reconditioned and counter belt replaced with #42-250).

ü Cracked counter 'worm gear' repaired

ü Heads have been cleaned and de-magnetized and are in great shape.

ü Record signal path contacts cleaned and burnished for static-free performance

ü Linear Record switch cleaned so no 'Motor Boating' effect

 ü Internal playback, meter and record level pots also adjusted w/ O-scope.

ü Following refurbishment, Speed checked with factory test tape to 98.2% accuracy! (meaning in this case, that our 1000Hz test tape plays back at 1018Hz on our Freq Counter Meter)

ü Deck 'sonically' checked for WOW and Flutter with no appreciable issues

ü Head azimuth & track cross-talk adjusted for optimum performance and the best high-frequency response (not normally expected from 8-track cartridge performance) utilizing RCA #356 and 8TSC-101, Aspen 'Deck Tester' and Audio-Tex 30-312 Test / Alignment tapes, a dual trace Oscilloscope and frequency counter.

ü Records acceptably well relative to most 8-Track decks (levels need to be 'pushed' while recording to maintain decent playback levels if you're going to be recording 8-tracks.)

ü Tuner string checked for any fraying then re-tensioned to increase traction & relieve flywheel binding and re-centered pointer to correct dial position.

ü We aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. FM sounds great. AM is above average as well relative to our standard tests.

ü All dial, indicator & meter lamps work well and are 'cool' running (meaning they have low current draw so should last years).

ü Stereo indicator lamp working

ü We also checked the heat sink compound which should be good for another 30 years.

ü All inputs tested and both side produces clean and even sine waves into 'brick-wall' 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.
Total restoration time investment 10+ hours.

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 72 hours into a 4 ohm load.

On our test bench, each internal amplifier of this particular unit, produced peak power of 11+ Volts per channel for 15+ Watts per channel @ 8 ohm and 9 Volts @ 4 ohm for 20 Watts per channel @ 1KHz via a STK439 Power pack. This is one of the few combo units that we did not have DC that was too high. AC Idle current at ~.25A, & floor noise -54dB.
  ____________________________
  
It really is surprising in sonics, performance, feel and quality. Great performance for a 'small to mid-sized' 2-Channel audio system. This is the only the second or third 'compact' to 'pass muster' in the past couple decades.
This quite a ‘Musical’ sounding receiver. Lot's of surprising 'punch' and volume.
Yes, I know, it's a 'compact' and not a 'separate component', but it really is that nice!!! Enough power for up to 'medium-large' / 10" woofer speakers.

Toshiba TMC-7550 Features:
  
Receiver features:
- Weighted flywheel, analog, slide rule tuning
- 5-Gang Tuning Capacitor
- Separate Bass and Treble controls utilizing high quality de-tented pots
- Oversize volume control,utilizing high quality de-tented pot
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
- FM Muting
- LED Stereo Indicator
- Hi filter for reducing tape hiss / electronic hiss & noise and record static
- Phono / Turntable input with Built-In Phono Pre-Amp
- Aux input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS®  etc.)
- Microphone Input to tape (be careful with your speakers if using an 'open / live' mic with home-audio speakers)
- A, B, or A+B speaker selector
- Standard 1/4" Stereo Headphone jack
- Built-in, internal AM ferrite bar antenna
- Dual Un-switched convenience AC outlet with 200 Watts capacity


8-Track Tape Deck features:
- Electronic / Power Assist Eject
- Auto-Electronic-Eject
- 'Auto-Level' Limiter for recording
- Locking Fast Forward
- 'Pause' function
- Analog / Mechanical Tape Counter
- Standard / 1/4" microphone inputs mounted on the front panel

Again, we have done the previously stated refurbishment / restoration work (~10+ hours) on this unit to insure its performance, and it gets our full 'Certification'. All functions tested for perfect operation. About the only cosmetic issue worth mentioning would be a few striations on the upper edge of the face plate (see photos above). Overall, it is in pretty good cosmetic condition! Looks and sounds great! Measures 19.75" wide x 6.75" tall x 12.5" deep and weighs 24 lbs unpacked. Includes our standard 30 day limited warranty.
Cond. 8.5
Toshiba TMC-7550 Stereo Receiver / 8-Track
$489.

(Cassette tape shown in photos for 'scale' only and not included, nor for sale)
(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

Did you know?
A SUPER LOW DISTORTION RATING COULD LIKELY BE A BAD THING!...
THD (Total Harmonic Distortion) – THD is a measure of the how much a given audio device may distort a signal through the inevitable introduction of added harmonics or overtones. These figures are usually given as percentages. THD figures below approximately 1% are inaudible to most people (although market promotion efficiencies have 'brain-washed' much of the 'audio-public' into weighting low THD with almost 'holy grail' importance. I remember some manufacturers touting numbers as low as <0.003% in the early Eighties).  Low THD is not always an indication of a high quality amplifier. In fact, it is / was more commonly just the opposite. Some of the 'highest end' (read REALLY expensive) and certainly best sounding units will have distortions somewhere between .1% & 1%.
Low THD is only a simple 'bi-product' of 2 aspects. The first was an inordinate and increasing amount of 'global / negative feedback' built into amplifiers primarily to suppress distortion. This practice started to occur in the late 1970's and certainly was in 'full force' past the early 1980's for most 'main stream' consumer-grade audio amplifiers. Unfortunately this also 'suppressed' tone and 'punch' (musicality) but it made the numbers look good to the 'spoon fed' consumer (kind of like overly high speaker wattage numbers, and sorry if you're in that group and, most folks were so you're not alone). Secondly manufacturers were moving away from 'discrete-transistor' output designs to more 'monolithic' 'power-pack' output designs. While these designs reduced power supply requirements, thus reducing parts costs and weight (also translates to lower prices due to savings on freight from Asia) they generally sounded anywhere from somewhat 'anemic' compared with the designs from a few years previous, to completely 'gutless' and 'un-musical'. But, hey,… they had very low distortion figures….Can anyone say 'threw the baby out with the bath water'?

Excerpts of the above text from the website of one of the best Car Audio sites and stores in the world, 'Car-Fi' www.car-fi.com .

  

 

 

Did you know?
What is the difference between a ‘Tuner’ and a ‘Receiver'?
A ‘Tuner’ is the component or aspect of an audio system that receives or ‘Tunes-In’ Radio Stations.
A 2-channel, stereo ‘Receiver’ is really 3 units in one!
It’s a ‘Tuner’ for receiving radio stations. It’s a ‘Pre-Amp / Control-Amp’ for source / input selection & tone / audio signal modification (with likely the phono 'pre-amp / head-amp' built-in). Lastly it’s a ‘Power Amplifier’ to energize your speakers. It's essentially the 'heart' of most audio / stereo systems.
Some manufacturers would silk-screen 'Tuner-Amplifier' on the front of their receivers, but that was / is simply 'marketing' to make it sound as if it's something more complicated. It's still a 'receiver'. Just FYI.


 

Jerry Gahagan, of Oak Tree Enterprises, LLC standing in front of one of a few 'batches' of speakers put together for an 'upper Mid-West' Micro-Brew chain.

 

A COUPLE OF 'AS-IS' RECEIVERS.
NORMALLY WE DON'T OFFER UP 'AS-IS' UNITS, BUT WE HAVE LIMITED TECH TIME, AND AS THESE ARE A COUPLE OF FAIRLY 'HIGH PROFILE' / SOUGHT-AFTER RECEIVERS WITH ONLY MINOR ISSUES...
 

         

           NEW LISTING 11/27/2021
(Click on above thumbnails to enlarge photos)
VINTAGE KENWOOD STEREO RECEIVER
"PROJECT", BUT VERY SOUGHT AFTER
KENWOOD KR-9600
HUGE POWER!
272 Watts / CHANNEL
#...1586
"WORLD AC POWER" ™
M.I.J.
for sale
Bench tested / technician checked, but missing 'cosmetic' parts, so was not restored, thus AS-IS -
All works and LOADS OF POWER!

ü Our technician has gone through this unit to a point

ü Some Dial, Meter, Stereo Indicator lamps work currently, but should all be replaced (Voltage measured at 'dial lamp' sockets @ 7.8VAC).

ü All inputs / functions tested including 'Phono input / pre-amp' and AM.

ü VERY importantly, even though the 'FM Stereo' bulb is burned out, it does go into 'Stereo Mode' and gets voltage (13VDC) to lamp leads.

ü Tuning Flywheel and tuner dial string all in fine shape and works well

ü All inputs tested and both sides produce clean and even sine waves into static 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.

ü Following basic bench check procedures, the unit was run continuously at medium volume, as all our amplifiers / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours and into a 4 Ohm Load!

ü On our test bench, the internal amplifiers of this Kenwood KR-9600 receiver, #...1586 produced 36 Volts per channel @ 8 Ohms with 1KHz input for 165 Watts and 33 Volts per channel @ 4 Ohms with 1KHz input for 272 Watts via Darlington TA-200 power packs.
ü AC 'draw' current at idle .5A
ü Bias adjusted to correct speck
ü DC offset / output measured at 28mVDC on L and 78mVDC on R.
ü Floor noise @ < -60dB either channel.
   ____________________________

Kenwood KR-9600 'Technical High Points'

- Dual Power Supply
- 8-Gang tuner (we've never seen that in any other tuner)
 - True "WORLD AC POWER" 50 / 60 cycles and 110V, 120V, 220V & 240V AC current

Loaded Kenwood KR-9600. Could make a great, classic receiver or heck, just use it 'as-is'. Or make a 'steam-punk' receiver out of it.
Anyway, missing it's sheet metal top / sides, dial glass / window, handles for front panel, "FM Mute" button, and feet. Yes, we could obtain those and finish it's restoration, too many other projects currently around the shop. We've had it almost a decade and thought instead of it collecting more dust, we would bench check it again, and offer it to some one as a project. Would also be great if you own a Kenwood KR-9600 that is cosmetically fine, but has technical issues. Just bolt on your cosmetic parts. See photos for complete condition.
KENWOOD KR-9600
AS-IS
$699.

(Any additional service / restoration work may be undertaken at any time and will be reflected in an adjustment in price.)

    

      NEW LISTING 7/23/19
(Click on above thumbnails to enlarge photos)
VINTAGE FISHER STEREO RECEIVER
THE CLASSIC FISHER 450-T
W/ "AUTOSCAN ELECTRONIC TUNING"
Circa 1969
#...3328
MADE IN USA
for sale
AS-IS - One channel not producing as much "Bass / Fullness of tone" as the other channel.

ü Our technician has gone through this unit to a point

ü Most Dial, Meter, Stereo Indicator lamps work currently (one dial lamp out)

ü Noisy pots / controls cleaned to facilitate service

ü Electrolytic power supply filter capacitors tested for leakage

ü A number of electrolytic capacitors changed in the 'audio path', but that made no difference in the tone (no, we didn't do all of them)

ü All 4 power transistors removed, tested for leakage (we actually switched sides to see if that made a difference in tone)

ü DC offset adjusted to low levels.

ü We also aligned the tuner 'front-end' for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. VERY GOOD TUNER! AM reception WAY above average, FM reception incredible, PUNCHY, with GREAT SEPARATION and IMPECCABLY CLEAN!!!

ü Entire unit cleaned cosmetically inside and out (but not detailed). Receiver looks good

ü One channel not producing as much "Bass / Fullness of tone" as the other channel. On the scope, there's noise on the left channel at around 300Hz, which is likely related to the lack of bass.?...

ü Missing one rubber foot (we didn't pursue due to diminished tone)

ü As a 'side note', ALL the original, brushed, anodized, aluminum 'Knob Brites' intact!

ü All inputs tested and both sides produce clean and even sine waves into static 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.

ü Following basic bench check procedures, the unit was run continuously at medium volume, as all our amplifiers / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours and into a 4 Ohm Load!

ü On our test bench, the internal amplifiers of this Fisher 450T receiver, #...3328 produced 21 Volts per channel @ 8 Ohms with 1KHz input for 55 Watts and 15 Volts per channel @ 4 Ohms with 1KHz input for 56 Watts via discrete, TO-3, metal cased, Motorola outputs (2x Motorola 1060 & 2x 2060).
ü AC Idle current at 220 mA
ü Bias adjusted to correct speck
ü DC offset output adjusted down to <10 mV DC either channel.
ü Floor noise @ < 0.1mVAC either channel.
   ____________________________

This is a very sought after model, but unfortunately it is lacking 'low end' response on one side. We pursued it for a few hours, but had 'bigger fish to fry' and we just don't have the tech resources to pursue it further (You can actually get both channels to sound similar by increasing the bass on one, and decreasing the bass on the other (it has separate L & R Tone controls) ) .
The 'Auto-Scan' function does work.
This is the first Fisher 450T we've had in almost 24 years of having the website. We've had it here a few years, but just now decided to sell it with one channel lacking as much bass as the other.
Cosmetically the unit is in overall great condition for being ~45 years old. Again, we really have only done a cursory cosmetic service. Unit looks good works great and sounds great! Includes an 'e' copy / pdf download of the original Fisher 450 owners / users / instruction manual. Measures 15.5" wide x 14.25" deep x 4.5" high and weighs 25 lbs unpacked.
Fisher 450t STEREO RECEIVER
Cosm Cond. 8+
$499. As-Is
(CONS. R.R.)

(Any additional service / restoration work may be undertaken at any time and will be reflected in an adjustment in price.)

(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

 

 

So, why do the older / 'vintage' receivers and amplifiers sound so much better (for music) than the much more modern and fancier, 'surround sound - '5.1', '7.1', '9 3/4.1' or '8.BR549' A/V receivers? (PART 1)

 
 Mostly due to Amplifier design and 'Amplification Classes' - All sound is a sinusoidal waveform. It has alternating peaks and valleys. The center point of each wave is the zero, or switching point that separates the positive (top) from the negative (bottom) portion of each wave. When a amplifier operates in 'Class A' , the output tubes or transistors amplify the entire waveform without splitting it into positive and negative halves. In 'Class AB', (used in the majority of classic receiver / amplifier designs), the signal is split into two halves, positive and negative, and each half is sent to a tube or transistor circuit for amplification. Both sides work in tandem, and the two halves are recombined at the output section to reconstruct the whole signal. This technique increases the amount of power that can be applied, but increases distortion.
In many 'modern' A/V and subwoofer amps, 'Class-D' is the dominant design method. Class D operation is essentially a rapidly switching power amplifier. Here the output devices are rapidly switched on and off at least twice for each cycle. Theoretically, since the output devices are either completely on or completely off they do not dissipate any power (heat), greatly increasing efficiency and lowering manufacturing cost thru lesser parts and lighter freight weight. Not musically the best sounding design (at least at the time of this writing) for listening to standard, 2-channel music (Radio, Vinyl, CD'S, DAT, Tape (not 'crappy' compressed, MP3 formatted files), but popular for 'A/V-Surround-Sound' systems for reproducing 'movie sound tracks' (not too difficult to do from a 'sonic quality standpoint') where slightly elevated levels of distortion are tolerated and for subwoofer use where maximum power is necessary, input voltage efficiency is important, and slightly elevated levels of distortion are also easily tolerated...Cont in Part 2 (also on this page)

Excerpts of the above text from the website of one of the best Car Audio sites and stores in the world, 'Car-Fi' www.car-fi.com .

  

 

What is a 'Receiver' and how is it different than a 'Tuner' or an 'Amp'?
The term 'Receiver' refers to a combined unit consisting of at least 3 aspects incorporated into one. The 3 basic units are the AM/FM 'Tuner' or radio, a 'Pre-Amplifier' / 'Control-Amp' and a 'Power-Amplifier' all combined in one 'box'. Originally the general consensus was that 'receivers' did not perform as well as 'separates' and were sonically inferior. While this may have been the case early on, as in the

 

late 1950's to early '60's, technology improved quickly and by the mid-late 60's the arguments for separates over receivers for most 'mid-level' consumer Hi-Fi applications were generally without merit. For 95% of home-audio listeners, a receiver will be more than ample.

Jerry Gahagan of OakTreeVintage
Taken in portion of Speaker Audition Room
Vintage Home Audio Speakers from the late 1960's into the 1980's

       

           NEW LISTING 11/19/2022
 (Click on above thumbnails to enlarge photos)
  warranty
RESTORED / REFURBISHED / FULLY SERVICED
VINTAGE PIONEER STEREO RECEIVER
PIONEER SX-880
"DISCRETE OUTPUTS!"
#...9835
Circa 1978-80
SOLD 2/5/2023
SHIPPING TO LINDA AND RICK IN KENTUCKY

Original Cond; "Very clean / kept well. Powers up. Lights up. No relay click, thus unable to test further."

ü Our technician has EXTENSIVELY gone through and 'Certified' this unit.



ü Amp has been cleaned inside and out. All internal control pots and switches are super quality.

ü All Internal fuses checked for continuity / values and all were correct values fortunately. (We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.)



ü Checked power supply board for correct Voltages.

ü Output transistors tested independently

ü Following initial restoration, two semiconductors found w/ questionable solder joints, another that was leaky in the protection circuit causing the receiver to go into protect mode prematurely when taxed a bit was replaced, and one transistor found with two legs intermittently touching which was causing the output speaker relay to be intermittent.   

ü DC offset adjusted to VERY LOW levels on either amplifier, and well below 'spec' levels (check results below).

ü Bias set to 30mV via VR7 & VR8 (spec is 30mV +/- 10mV). Nice, even sine waves to both rails up to 24.5VAC.

ü All Dial / Meter replaced with blue-tinted lamps for trouble free service (3x #280).

ü We also aligned the dial pointer / tuning capacitor to match the dial scale via "TC3" adjustment

ü We also aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. The tuner works exceptionally well in our warehouse. Picks up both AM and FM bands way above average!!!

ü All inputs tested and both side produces clean and even sine waves! No power supply hum of any kind. It's dead silent! All functions test fine. 

ü Entire unit cosmetically detailed in and out. The wood grain wrapping does have a few peels, scraps and scuffs here and there (see photos above).

ü Total Tech time investment ~13 hours.
  
On our test bench, this unit's amplifiers 24.5 Volts per channel at 8 Ohms for 75 Watts per channel and 21.4 Volts per channel at 4 Ohms for 114 Watts each channel via Discrete outputs (2x NEC B705A & 2x NEC D745A outputs)
ü AC Idle current at .28A.
ü Bias adjusted to spec.
ü DC offset output <5mVDC either channel (spec is +/- 30mV)
ü Floor noise at -74dBu either channel.
  ____________________________
  
This is the first Pioneer SX-880 we've had since 2008. Very nice medium-large sized receiver with lots of solid power and plenty of features. Has that great milled aluminum look in a "Wood-Grain" vinyl wrapped case.

Pioneer SX-880 Features include:
    
- Classic 2-Channel, Class A/B amplifier design W/ DISCRETE OUTPUT TRANSISTORS



- Analog Weighted Flywheel tuning on full-width back-lit slide rule tuning scale
- Classic and hand-some, brushed aluminum, ''SLIVER FACE'
- Gorgeous back-lit meters
- Separate Bass and Treble controls featuring high quality, de-tented pots
- Dual back-lit analog VU Power Level meters
- AM / FM Analog VU meter for Signal Strength and Tuning
- Built-in Low filter to reduce turn-table rumble and speaker rumble
- FM Muting Selector (separate from the 'Stereo' selector)
- Aux input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS®  etc.)
- Dual tape monitors (Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Tape 'Dubbing' capability
- Phono / Turntable input w/ built-in phono pre-amp
- Stereo / Mono selector for all inputs, not just the FM tuner
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
- A, B, A+B & Off speaker selector
- 1/4" Stereo headphone jack
- Rear panel features selectable FM De-Emphasis at 25 or 75 μSec (micro-seconds).
- Dual AC convenience outlets (1 switched & 1 un-switched for a total capacity of 400 Watts current)
  
Authors note about the boundary between the Pioneer SX-780 and the SX-880; "So while the 'little brother' to this receiver, the Pioneer SX-780 was the "most sold of any stereo receiver, ever, by anybody", it was primarily because the SX-780 gave the same features as the "SX-880" for less money. The reason they could do that was that the "780" had a Sankyo, Darlington STK-0050, single output device (chip) for it's amplifier channels (one L and one R). While that doesn't give as 'punchy' of a sound as separate, discrete output transistors (which had been the standard pretty much forever prior to that), it was able to deliver decent Wattage (at least mathematically) to be acceptable for most listeners and hit a lower price point. The Pioneer SX-880 design (and all the models above it) however, seemed concerned with 'price point' thus was designed with true, discrete output transistors / devices, which while more expensive to build, delivered more traditional, punchier sound than the inexpensive 'chips' did (and still do) (and allows bias to be adjusted. The STK chip does not typically have adjustable bias).
This receiver also features a very nice design feature in that the output devices are mounted on the bottom side of the heat sinks for less dust build-up which will allow them to run much cooler for a longer life and tighter sound."
  
Original Pioneer SX-880 Specifications:

"The SX-880 has a continuous power output of 60 Watts per channel min. @ 8 ohms from 20 hertz to 20,000 hertz with no more than 0.05% total harmonic distortion, or 45 Watts per channel at 4 ohms from 20 hertz to 20,000 hertz with no more than 0.08% total harmonic distortion"
 
 POWER / PRE AMP SPECIFICATIONS:
Design type: 2 Channels, Integrated Pre /
Class AB operation Power Amplifier
Freq Response: 20Hz-20KHz at full rated power
 - Potential frequency response of power amp section @ 1W; 5-80,000Hz ±0dB
Power Output: Continuous power output, 20Hz-20,000Hz;
60 W/Ch.
S/N: 95dB @ AUX and / or TAPE
Damping Factor; 30 w/ 8 Ohms load @ 20Hz-20,000Hz;
Bass Control; +8dB / -7dB @ 100Hz
Treble Control; +7dB / -6dB @ 10KHz
Low Filter; ~-6dB @ 15Hz & 6dB / Oct
Loudness Control @ -40dB; +6dB @ 100Hz & +3dB @ 10KHz
Input Sensitivity / Impedance AUX and / or Tape; 150mV & 50kΩ
Record Out Terminals (RCA); 150mV @ 1kΩ
THD; 0.30% @ 8 Ohms @ half power
THD at full rated power - 0.050%

TUNER SPECS FOR FM;

Tuning Capacitor: 5 gang, 3 FM / 2 AM
Freq Response: 30-15KHz (limited by FCC)
Capture Ratio: 1.0dB
Image Response Ratio: 65dB
Spurious Noise Ratio: 65dB
AM Suppression Ratio: 50dB
IF Response Ratio: 90dB
Subcarrier Product Product Ratio: 55dB
Muting Threshold: 10μV
Signal-To-Noise Ratio (Stereo) @ 65dBf (1mV) output: 72dB
Signal-To-Noise Ratio (mono) @ 65dBf (1mV) output: > 80db
Mono Sensitivity for 50dB quieting; 16.2 dBf / 3.6μV
Stereo Sensitivity for 50dB quieting; 37.0 dBf / 39μV
De-Emphasis; 25/75 μSec Selectable
THD @ 1KHz Mono;  0.15%
THD @ 1KHz Stereo;  0.07%
FM Alternate Channel Selectivity: 75dB
FM separation; 45dB @ 1kHx
 
 PHONO SECTION SPECS;
Freq Response: 20Hz-20KHz (30-15kzHz RIAA EQ)
S/N: 76dB @ PHONO
Sensitivity; 2.5 mV / 50KOhms
Overload limit; 200 mV (and still maintain THD spec)
  
Again, as stated before, our technician has completely refurb'd this Pioneer SX-880 Receiver, cleaning and testing all and it gets our full 'Certification'. Cosmetically there's a couple of tics along the top edge of the face plate, and a few minor finish blems on the side panels, but nothing really distracting (see photos above). It's a great performing and fabulous sounding unit. Great for systems from medium to fairly large. At over 100 Watts at into ohms, there's enough power to 'do some damage', volume wise. Measures 19" wide x 14.5" deep x 6.25" tall and weighs 28 lbs unpacked. Includes our standard 30 day limited warranty.
  PIONEER SX-880 AM/FM STEREO RECEIVER
Cond. 8.5

SOLD 2/5/2023
SHIPPING TO LINDA AND RICK IN KENTUCKY
 (C)
R.R.

(Above text property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

         

            

                 NEW LISTING 11/19/2022
 (Click on above thumbnails to enlarge photos)
  warranty
RESTORED / REFURBISHED / FULLY SERVICED
VINTAGE KENWOOD STEREO RECEIVER
"TOPL" for the time period
KENWOOD KR-7070
"DISCRETE, TO-3 OUTPUTS!"
300 Watt* Powerhouse!
#...1134
Circa 1970-73
MIJ
SOLD 8/11/2023
SHIPPING TO RAY IN NEVADA

ü Our technician has EXTENSIVELY gone through and 'Certified' this unit.

ü Amp has been cleaned inside and out. All internal control pots and switches are super quality.

ü New AC / Mains cord installed

ü All Internal fuses checked for continuity / values and all were correct values fortunately. (We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.)

ü Checked power supply board for correct Voltages.

ü Output transistors tested independently

ü Cleaned / Burnished PCB edge connectors

ü All Dial / Meter replaced with new X6 #25-090. (input indicators all test fine and are 'low-output / cool running' units)

ü We also aligned the dial pointer / tuning capacitor to match the dial scale

ü We also aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. The tuner works exceptionally well in our warehouse. Picks up both AM and FM bands way above average!!!

ü While the tuner has an 'Auto-matic' function to it, we were not able to get any function from that aspect, and frankly as it's such an 'low priority' function, did not spend an inordinate amount of resources to restore any of it's original function.

ü All inputs tested and both side produces clean and even sine waves! No power supply hum of any kind. It's dead silent! All functions test fine. 

ü Entire unit cosmetically detailed in and out.

ü Total Tech time investment ~10 hours.
  
On our test bench, this unit's amplifiers 26+ Volts per channel at 8 Ohms for 84 Watts per channel and 21+ Volts per channel at 4 Ohms for 110 Watts each channel via Discrete, TO-3, metal cased outputs (4x Hitachi 2SC989 outputs)
ü AC Idle current at .45A.
ü DC offset (cap coupled)
ü Floor noise at -54dB either channel.
  ____________________________
  
This is the first Kenwood KR-7070 we've ever had. Very nice, larger sized receiver with lots of solid power, plenty of features and in my opinion, one of the most 'musical sounding' pre-amp sections of about any unit we've ever had. Unit in decent cosmetic shape with a bit of discoloration on the face plate, and some minor flaking of the inner-most coating of the dial window (see photos above). Real wood veneer cabinet.

Kenwood KR-7070 Features include:
    
- Classic 2-Channel, Class A/B amplifier design with Metal Cased, TO-3 devices (best, most expensive way to build an amp)
- Analog Weighted Flywheel tuning on full-width back-lit slide rule tuning scale
- Pre-Amp / Power Amp loop (allows Pre-amp to feed others systems / amplifiers or other pre-amps / mixers to feed power amp separately. This can be one of the handiest features of a receiver / integrated amplifier, and is typically only found on a brands 'mid-upper' to 'upper-end' models)
- 7-Gang Tuning Capacitor
- Gorgeous back-lit dial and meter
- Separate Bass and Treble controls featuring high quality, fixed resistor, wafer selectors in +/-2dB increments (no carbon trace pots to get dirty)
- AM / FM Analog VU meter for Signal Strength
- Built-in Low filter to reduce turn-table rumble and speaker rumble
- Hi / MPX filter for reducing the 19KHz pilot tone and 38KHz harmonic in FM broadcasts
- FM Muting Selector (separate from the 'Stereo' selector)
- Built-in AM 'Stick' antenna on hinged mounting bracket
- FM Multipath outputs (Vertical and Horizontal) for visual monitoring via an Oscilloscope or similar video mon
- Aux input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS®  etc.)
- True tape monitor (Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc) featuring both RCA and DIN I/O's
- Dual Phono / Turntable inputs w/ built-in phono pre-amp and triple position sensitivity adjustment for Phono-1
- Microphone inputs (via RCA's on rear panel) (be careful with 'home audio speakers' and open microphones)
- Stereo / Mono selector for all inputs, not just the FM tuner (also allows L or R and Reverse Stereo. Very handy for trouble-shooting speaker / room issues)
- 2 Position "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
- "Presence" selector
- Front located, Tape Dubbing Jack (simply at Tape output located on the front panel. Would need a TRS male plug to utilize)
- -20dB Instant Audio Muting switch
- A, B, A+B & Off speaker selector
- 1/4" Stereo headphone jack
- Built-in Short Circuit protection for outputs
- Dual external speaker / output protection fuses
- External 'mains / power' protection fuse
- Triple AC convenience outlets (2 switched @ 200 Watts & 1 un-switched @ 300Watts for a total capacity of 500 Watts current)
  
Original Kenwood KR-7070 Specifications:

"The KR-7070 has a total power output of 350 Watts @ 4 ohms"
 
 POWER / PRE AMP SPECIFICATIONS:
Design type: 2 Channels, Integrated Pre /
Class AB operation Power Amplifier, Cap Coupled
Freq Response: 20Hz-20KHz at full rated power
Power Bandwidth / Potential frequency response of power amp section @ 1W; 10-30,000Hz ±0dB
Power Output: Continuous power output,
Single Channel Driven: 1KHz = 110 W/Ch @ 4 Ohms
Single Channel Driven: 1KHz = 90 W/Ch @ 8 Ohms
Both Channels Driven: 1KHz = 95 W/Ch @ 4 Ohms
Both Channel Driven: 1KHz = 80 W/Ch @ 8 Ohms
Both Channel Driven: 20Hz-20,000Hz; = 65 W/Ch @ 8 Ohms
*Dynamic / Music Power, IHF; Both Channels Driven: 300 Watts @ 4 Ohms
Dynamic / Music Power, IHF; Both Channels Driven: 220 Watts @ 8 Ohms

S/N: 75dB @ AUX and / or TAPE
Damping Factor; 50 w/ 8 Ohms load or 100 w/ 16 Ohms load @ 20Hz-20,000Hz;
Bass Control; +10dB @ 100Hz in +/-2dB increments
Treble Control; +10dB @ 10KHz in +/-2dB increments
Low Filter; -7dB @ 100Hz & 6dB / Oct
High Filter; -10dB @ 10KHz & 6dB / Oct
Loudness Control @ -30dB; +10dB @ 100Hz & +5dB @ 10KHz
Presence Control @ -30dB; +6dB @ 1KHz & +6dB @ 400Hz
Audio Muting; -20dB
Input Sensitivity / Impedance AUX and / or Tape; 200mV & 100kΩ
Record Out Terminals (RCA); 200mV
THD; 0.05% @ 8 Ohms @ 3dB less than full power
THD at full rated power - 0.50%

TUNER SPECS FOR FM;

Tuning Capacitor: 7 gang, 4 FM / 3 AM
Freq Response: 20-15KHz (limited by FCC)
Capture Ratio: 1.5dB
Image Rejection: 100dB
Spurious Noise Rejection: >100dB
AM Suppression Ratio: >55dB
IF Rejection: 100dB
Subcarrier Suppression: 55dB
Muting Threshold (manual): 10μV
Signal-To-Noise Ratio: >70dB
Sensitivity for 50dB quieting;1.5μV
THD @ 400Hz w/ 100% modulation in Mono;  <0.4%
THD @ 400Hz w/ 100% modulation in Stereo;  <0.6%
FM Alternate Channel Selectivity: >75dB
FM separation; >35dB @ 1KHz

TUNER SPECS FOR AM:
Useable Sensitivity IHF; 15uV
Selectivity: >30dB
Image Rejection; >70dB
S/N; >50dB w/ 1mV input
IF Rejection: >60dB
 
 PHONO SECTION SPECS;
Freq Response: 20Hz-20KHz (30-15kzHz RIAA EQ)
S/N: 65dB @ PHONO 1 or 2 w/ 2.5mV input
Sensitivity; Switch-able for 0.05mV, 0.5mV or 2.5 mV / 50KOhms Phono 1
2.5 mV / 50KOhms Phono 2
  
Again, as stated before, our technician has completely refurb'd this Kenwood KR-7070, cleaning and testing all and it gets our 'Certification' (again, with the exception of the 'Auto-tuning' function). Cosmetically there's a some 'splotches' on the face panel, but nothing really distracting (see photos above). It's a great performing and fabulous sounding unit. Authors note; "This unit has one of the most versatile and 'Musical' sounding pre-amps I've ever auditioned. Smartly designed tone controls, filters and tone selectors! Loads of Bass (when desired), and great control of the overall tone. Very 'punchy' front end."
Includes a pdf, 'e' copy, download of the Kenwood KR-7070 owners / users / instruction manual.
Great for systems from medium to fairly large. At over 325 Watts at into 4 Ohms, there's enough power to 'do some damage', volume wise. Measures 17" wide x 15" deep x 6.5" tall and weighs a hefty 40 lbs unpacked. Includes our standard 30 day limited warranty.
KENWOOD KR-7070 AM/FM STEREO RECEIVER
Cond. 8.5
(C) R.R.
SOLD 8/11/2023
SHIPPING TO RAY IN NEVADA
 

(Above text property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

         

             NEW LISTING 7/22/2022
  (Click on above thumbnails to enlarge photos) 
warranty
FULLY SERVICED / REFURBISHED / WARRANTED
PRE-APPRECIATED NAD STEREO RECEIVER
NAD 7220PE RECEIVER
#...7612
 Circa 196-87
SOLD 11/16/2022
SHIPPING TO TERRY IN MASSACHUSETTS

Original Cond; "Very clean / kept well. Powers & Lights up. No 'Right' channel output. Found a low 14mVDC on left channel, BUT 2.9VDC on right side of output."

ü Our technician has EXTENSIVELY gone through and 'Certified' this unit.
 
ü Essentially rebuilt the right channel. Found Transistors; Q410, 412, 414, 416 & 418 bad, as well as a burned resistor, a capacitor that received a proximity burn and two 'green legged' jumpers. Balance of semiconductors tested in that channel. All bad / questionable transistors were replaced with quality, proper NTE substitutions. NO Chinese counterfeit / knockoff parts!!!

ü Entire unit was cleaned out including all contacts, switches and controls. Switches now clean sounding and performing solidly. Controls are smooth and silent.
 
ü Silicone heat sink compound replaced
 
ü Output section bias adjusted to factory spec 28mVDC per service manual
 
ü Output DC offset adjusted to 0mVDC!!! L & R
 
ü Solder joints reflowed where necessary on all possible high heat and stress points

ü All Controls / Switches cleaned and test for quietness

 ü All functions tested for perfect operation.
 
 ü All inputs and functions tested.
 
 ü Both amplifier sides produce clean and even sine waves! No power supply hum of any kind. It's dead silent!
 
 ü Following electronic refurbishing, the entire unit was cosmetically detailed.
 
ü Following restoration procedures, the unit was ran continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours.

While this model was originally rated at 20 Watts / channel, on our test bench, this unit's (#...7612) amplifiers produced 19.6 Volts per channel at 8 Ohms for 47 Watts per channel or 16.5 Volts at 4 Ohms for 68 Watts per channel via discrete, TO-3, metal cased output devices (2x 2N3055 & 2X MJ2955). 
 AC Idle current at 280mA, Bias adjusted to spec @ 28mV +/-2mV,
and while the measured DC offset was a respectable 14mVDC on left channel when it arrived (remember, right channel appeared with no output, but high DC), we managed to adjust the DC offset to ZERO mVDC on either channel!
Floor noise @ >-74dB either channel.
 This NAD is even stable for limited amounts of time into 2 Ohms!
   ____________________________

Classic NAD 7220PE, Stereo Receiver. NAD gear is famous for very plain, almost military appearances, but solid performance with lots of headroom. I used to sell these new and never remember an NAD owner who wasn't proud to own one, nor whoever switched from NAD once they owned their first.

NAD 7220PE Features include:
 
- 5 AM & FM station presets
- Manual Station / Frequency scanning
- Speaker output impedance selector 8 or 4 Ohms speakers (a very important aspect of this unit meaning that you can get 100% FULL output into just ONE set of 8 Ohm speakers. All amplifiers / receivers should have this)
- "Extra Speakers" selector allows an additional pair of speakers to be added to the "Main" speakers ("Main" speakers are always on)
- Loudness Compensation function to increase bass and treble response to achieve a 'fuller' sound while at lower volume levels
- CD (AUX) input for (Video / CD / DVD / VCR / DAT / MP3 / XM / SIRIUS / TV / iPod® / iPhone® / iTouch® / iGadget / MP3 /  etc.)
- Phono / Turntable input with built-in Phono pre-amp.
- TRUE Tape monitor (Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Binding Post / Banana Jack Speaker outputs (work very well)
- NAD's "Soft Clip" feature for speaker protection and smoother sound at higher volumes (can be defeated)
- 1/4" stereo headphone jack (kills output to speakers)
- Rear located, full barrier strip for external antenna connections
- Dual Convenience AC outlets on rear panel; 1x 'Un-switched' for up to 250 Watts and 1x 'switched' for up to 250 Watts

Original NAD 7220PE Specifications:

"The NAD 7220PE has a continuous power output of 20 Watts per channel min @ 8 Ohms from 20 hertz to 20,000 hertz with no more than 0.04% THD (measured utilizing AUX input)"
 
POWER / PRE AMP SPECIFICATIONS:
THD: 0.04% from 250mW to rated output of 20 Wpc @ 8 Ohms
Dynamic Headroom at 8 Ohms: +4.4dB
IHF dynamic MAX short term: 55W @ 8 Ohms, 75W @ 4 Ohms, 85W @ 2 Ohms
Slew factor: >50 @ 8Ω full bandwidth
Slew Rate: 15V / uSec @ 8Ω full bandwidth
Damping factor: >30 @ 8Ω full bandwidth
Tone Control ranges:
Bass: +/-10dB @ 50Hz
Treble: +/-7dB @ 10KHz
Pre-Amp THD @ rated output: <0.04%
Pre-Amp S/N @ 'Tape' & 'AUX': >97dB ref 20W output
Pre-Amp Input Sensitivity @ 'Tape' & 'AUX': 33mV for 1W output & 150mV for 20W output
Line Level Output Imp:
Pre-Out; 600 Ohms
Tape-Out; Source Z + 2kOhms
Headphones; 200 Ohms
Line Level Outputs Max Voltages:
Pre-Out; 12V
Tape-Out; 10V
Headphones; 10V into 600 Ohms / 500mV into 8 Ohms

TUNER SPECS FOR FM:
Tuning Range; ~87.5-108.0MHz
Freq Response; 30Hz-15KHz (limited by FCC)
S/N @ 68 dBf; > 74db Stereo & 80dB Mono
50dB Quieting Sensitivity; Mono; (14.4 dBf / 2.9μV)
50dB Quieting Sensitivity; Stereo; (37dBf / 40μV)
Capture Ratio; 1.5dB
AM Rejection: >60dB
FM Alternate Channel Selectivity: 58dB
Image Rejection; >70dB
Subcarrier suppression: 60dB
THD @ 65dBf Mono or Stereo @ 1KHz; 0.1%
Stereo Separation; >45dB @ 1KHz

TUNER SPECS FOR AM:
Tuning Range; ~520-1710KHz
Useable Sensitivity IHF; 5 uV
Selectivity: 30dB
Image Rejection; >45dB
S/N; >45dB
THD; 0.5%

PHONO SECTION SPECS:
Freq Response: RIAA +/-5dB
S/N: 75dB w/ MM cart w/ 5mV
RIAA Response Accuracy: +/- 0.5dB
Input Sensitivity / Impedance: 0.55mV @ 47kΩ for 1 W and 2.4mV for 20 W output
Overload limit 20Hz / 1KHz / 20KHz: 20 / 200 / 1700mV
 
Again, we have completely gone through this NAD 7220PE Stereo Receiver, as stated above and 'certified' it's 'Ready To Go'! Cosmetically it looks essentially NEW. Couple of light scratches on the top sheet metal.
Includes a pdf, 'e' copy, download of the NAD 7220PE owners / users / instruction manual, and brochure.
Unit looks and sounds great! Measures 16.5" wide x 10.75" deep x 3.6" tall and weighs 15 lbs unpacked.
Cond. 8.5+++
NAD 7220PE
(C) M.S.
SOLD 11/16/2022
SHIPPING TO TERRY IN MASSACHUSETTS


(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

 

         

         NEW LISTING 12/17/2021
  (Click on above thumbnails to enlarge photos) 
warranty
FULLY SERVICED / REFURBISHED / WARRANTED
PRE-APPRECIATED NAD STEREO RECEIVER
NAD 7225PE RECEIVER
#...3232
 Circa 1988
SOLD 5/3/2022
SHIPPING TO STEVE IN IDAHO

ü Our technician has EXTENSIVELY gone through and 'Certified' this unit. Unit disassembled, then everything was cleaned inside and out including all switches, controls and contacts. Extensive cleaning of unit internally. Controls were 'flooded' w/ 'De-OxId' and are quiet. Internal fuses checked for correct value / function and replaced where necessary. We also aligned the tuner front-end on both AM & FM bands for optimum performance as older tuner components will have 'drifted' over the years. Amplifier section had output bias and DC offset adjusted to spec levels. All indicators checked and are LED's for trouble-free service.
All inputs tested and both sides produce clean and even sine waves into 'brick-wall' 8 & 4 ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine, including tuner pre-sets. Following restoration procedures, the unit was ran continuously at medium volume, as all our amplifier / receivers are, into a 4 Ohm load with "Loudness" on and both Tone Controls at 10 for 48+ hours. You will not be disappointed.

While this model was originally rated at 25 Watts / channel, on our test bench, this unit's (#...3232) amplifiers produced 19.4 Volts per channel at 8 Ohms for 47 Watts per channel or 17 Volts at 4 Ohms for 72 Watts per channel via discrete, TO-3, metal cased output devices (2x 2N3055 & 2X MJ2955). 
 AC Idle current at 260mA, Bias adjusted to spec @ 28mV +/-2mV,
and while the measured DC offset was 30mVDC on either channel when it arrived (just within spec), we managed to adjust the DC offset to LESS THAN 1mVDC on either channel!
Floor noise @ >-74dB either channel.
 This NAD is even stable for limited amounts of time into 2 Ohms!
   _____________________________

Classic NAD 7225PE, Stereo Receiver. NAD gear is famous for very plain, almost military appearances, but solid performance with lots of headroom. I used to sell these new and never remember an NAD owner who wasn't proud to own one, nor whoever switched from NAD once they owned their first.

NAD 7225PE Features include:
 
- 5 AM & FM station presets
- Manual Station / Frequency scanning
- Speaker output impedance selector 8 or 4 Ohms speakers (a very important aspect of this unit meaning that you can get 100% FULL output into just ONE set of 8 Ohm speakers. All amplifiers / receivers should have this)
- Loudness Compensation function
- Low-Level EQ compensation switch
- CD (AUX) input for (Video / CD / DVD / VCR / DAT / MP3 / XM / SIRIUS / TV / iPod® / iPhone® / iTouch® / iGadget / MP3 /  etc.)
- Phono / Turntable input with built-in Phono pre-amp.
- TRUE Tape monitor (Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Pre-Amp Out / Main / Power-Amp In loop via standard RCA's
- Binding Post / Banana Jack Speaker outputs (work very well)
- NAD's "Soft Clip" feature for speaker protection and smoother sound at higher volumes (can be defeated)
- 1/4" stereo headphone jack (kills output to speakers)
- Rear located, full barrier strip for external antenna connections
- Dual Convenience AC outlets on rear panel; 1x 'Un-switched' for up to 250 Watts and 1x 'switched' for up to 250 Watts

Original NAD 7225PE Specifications:

"The NAD 7225PE has a continuous power output of 25 Watts per channel min @ 8 Ohms from 20 hertz to 20,000 hertz with no more than 0.03% THD (measured utilizing AUX input)"
 
POWER / PRE AMP SPECIFICATIONS:
THD: 0.03% from 250mW to rated output of 25 Wpc @ 8 Ohms
'Clipping' Headroom at 8 Ohms: +1.5dB
Dynamic Headroom at 8 Ohms: +4dB
IHF dynamic MAX short term: 60W @ 8 Ohms, 85W @ 4 Ohms, 95W @ 2 Ohms
Damping factor: >50 @ 8Ω full bandwidth
Tone Control ranges:
Bass: +/-10dB @ 50Hz
Treble: +/-7dB @ 10KHz
Pre-Amp THD @ rated output: <0.03%
Pre-Amp S/N @ 'Tape' & 'AUX': >99dB ref 25W output
Pre-Amp Input Sensitivity @ 'Tape' & 'AUX': 160mV for 25W output
Line Level Output Imp:
Pre-Out; 600 Ohms
Tape-Out; Source Z + 2kOhms
Headphones; 200 Ohms
Line Level Outputs Max Voltages:
Pre-Out; 12V
Tape-Out; 10V
Headphones; 10V into 600 Ohms / 500mV into 8 Ohms

TUNER SPECS FOR FM:
Tuning Range; ~87.5-108.0MHz
Freq Response; 30Hz-15KHz (limited by FCC)
S/N @ 68 dBf; > 74db Stereo & 80dB Mono
50dB Quieting Sensitivity; Mono; (15 dBf / 3μV)
50dB Quieting Sensitivity; Stereo; (37dBf / 120μV)
Capture Ratio; 1.5dB
FM Alternate Channel Selectivity: 58dB
Subcarrier supression: 60dB
THD @ 65dBf Mono or Stereo @ 1KHz; 0.1%
Stereo Separation; >45dB @ 1KHz

TUNER SPECS FOR AM:
Tuning Range; ~520-1710KHz
Useable Sensitivity IHF; 5 uV
Selectivity: 30dB
Image Rejection; >45dB
S/N; >45dB
THD; 0.5%

PHONO SECTION SPECS:
Freq Response: RIAA +/-5dB
S/N: 75dB w/ MM cart w/ 5mV
RIAA Response Accuracy: +/- 0.3dB
Input Sensitivity / Impedance: 0.5mV @ 47kΩ for 1 W and 2.5mV for 25 W output
Overload limit: 1.15V @ 20KHz
THD: 0.04% across 20-20KHz
 
Again, we have completely gone through this NAD 7225PE Stereo Receiver, as stated above and 'certified' it's 'Ready To Go'! Cosmetically it's quite nice. There a light scratch on the face and some small marks along the bottom, edge of the face plate, and a few scratches on the right side panel (not really distracting, and only noticeable in certain light / angles. see photos above).
Includes a pdf, 'e' copy, download of the NAD 7225PE owners / users / instruction manual, and brochure.
Unit looks and sounds great! Measures 16.5" wide x 10.75" deep x 3.6" tall and weighs 15 lbs unpacked.
Cond. 8.5
NAD 7225PE
SOLD 5/3/2022
SHIPPING TO STEVE IN IDAHO


(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

    

NEW LISTING 11/27/2021
(Click on above thumbnails to enlarge photos) 
warranty
RESTORED / REFURBISHED / FULLY SERVICED / WARRANTED
PRE-APPRECIATED ONKYO STEREO RECEIVER
ONKYO TX-6000 RECEIVER
#...4213
Circa 1979 into early 1980's
M.I.J.
SOLD 12/8/2021
SHIPPING TO CHRIS IN NEW YORK

ü Our technician has EXTENSIVELY gone through and 'Certified' this unit.

ü We have completely gone through this unit cleaning everything including all switches, controls and contacts.

ü Internal fuses checked for continuity and correct values. No issues found, fortunately. We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.

ü Controls were 'flooded' w/ 'De-OxId' and are quiet 

ü Both main power supply filter capacitors were changed as one was physically leaking. It was actually causing the unit not to come up past 20 Volts of output. Upon testing the caps out of the unit for many parameters, they actually tested as 'good', but once changed, the new capacitors allowed the unit to reach full voltage. The originals were rated for 15,000Mfd / 55V, but we replaced with new 63V.


ü Bias was originally WAY OFF measuring 0VDC. We adjusted to correct 19 (+/-2) mVDC.

ü DC offset measured at an amazingly LOW 1mVDC on either amplifier.

ü All inputs tested and both side produces clean and even sine waves into 'brick-wall' 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 72 hours into a 4 Ohm load.

ü 10x indicator bulbs replaced (25-1370 / 12V/0.05A)

ü All inputs tested and both side produces clean and even sine waves into static 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine. Following restoration procedures, the unit was ran continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours.
 
ü On our test bench, the internal amplifiers of this Onkyo TX-6000 receiver, #...4213 produced 26 Volts per channel @ 8 Ohms with 1KHz input for 84+ Watts and 22 Volts per channel @ 4 Ohms with 1KHz input for 121 Watts via discrete, output transistors.
ü AC current draw at idle measured at 0.5A.
ü Floor noise measured @ >-74dB AC either channel.

ü Real, discrete output transistors, mounted on super efficient, vertically finned, heat-sink for max cooling efficiency (after all, 'heat' is the main 'killer' of electronics).  

Speaker outputs are protected by internal automatically resetting relays and output section is thermal protected. (Authors note; "This receiver is one of the most "musical sounding" and punchy receivers I've used in a long time"

ONKYO TX-6000 Features include:

- Digital tuning with 7, random AM / FM presets
- Circuit Boards populated with 'REAL' components (NOT anemic SMD components)
- True, Discrete Amplifier Outputs (NOT STK chips / Darlington packs)
- Auto / Manual tuning modes
- A, B, A+B and 'Off' speaker selector
- Fluorescent and LED displays for digital station readouts, Tuning signal strength, Tuning, Station Presets
- Dual, 12-Segment, LED power meters
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
 - Separate Bass and Treble controls
- Dual TRUE tape monitors (Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Bi-Directional Tape 'Dubbing' capability
- "E.P.S." (Not to be confused with E.S.P., which is different...) Anyway, "E.P.S." stands for "External Processing Loop", which is and In / Out / Side-chain to connect external signal processors such as an EQ, Reverb, Sonic Hologram, Compander / Expander etc. without consuming one of your tape monitors (although most 'consumer' level signal processors give you back the tape monitor they utilized, but not all)
- Video-1 input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS®  etc.)
- Video-2 / Aux input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS®  etc.)
- CD Direct (bypasses all the tone and Sonic Holography circuitry providing the purest audio signal path) (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS®  etc.)
-  Phono / Turntable input with Built-In Phono Pre-Amp for either standard, Moving Magnet / MM cartridges or for Moving Coil / MC cartridges.
- ¼" stereo headphone jack
- Dual AC convenience outlets (1x switched 100W /  1x un-switched 100W)

Onkyo TX-6000 Original Specs:

POWER / PRE AMP SPECIFICATIONS:
THD; 0.03% @ full rated power
Cont rated Power: 2x 70 Watts @ 8 Ohms / 20-20KHz
S/N; >95dB on AUX / Tape
Damping Factor; 50 @ 8 Ohms
Frequency Bandwidth; 15Hz-30KHz
Input Sensitivity AUX / Tape; ~150mV @ 50kΩ
Record Out Levels; ~150mV
Bass Control; ±12dB @ 100Hz
Treble Control; ±0dB @ 10KHz
"Loudness" Contour;  approx; +8dB @ 40Hz, +5dB @ 10KHz (w/ volume set at -40dB)
High Filter; 6dB / Oct @ 6KHz
Subsonic Filter; 6dB / Oct @ 10Hz

TUNER SPECS FOR FM:
Tuning Range; ~87.9-107.9MHz
Freq Response; 30Hz-15KHz (limited by FCC)
S/N @ 85 dBf; > 68db Stereo & 73dB Mono
Image Rejection; >80dB
Useable Mono Sensitivity; 10.3 dBf / 1.8 uV
Useable Stereo Sensitivity; 17.2 dBf / 4.0 uV
50dB Quieting Sensitivity; Mono; (14.7 dBf / 3 μV)
50dB Quieting Sensitivity; Stereo; (37.2 dBf / 40 μV)
Capture Ratio; 1.4dB
IF Rejection: >90dB
Spurious Rejection: >90dB
FM Alternate Channel Selectivity: 70dB
AM supression: 55dB
Subcarrier supression: 60dB
THD @ 65dBf Mono @ 1KHz; 0.12%
Stereo Separation; >40dB @ 1KHz

TUNER SPECS FOR AM:
Tuning Range; ~530-1620KHz
Useable Sensitivity IHF; 25 uV
Image Rejection; >45dB
I.F. Rejection; >35dB
S/N; >40dB

PHONO SECTION SPECS:
Freq Response; 20-20KHz RIAA Standard Curve +/- 0.2dB
S/N on MM; >76dB
Input Sensitivity MM; 2.5 mV @ 50kΩ
Input Sensitivity MC; 350 uV @ 330Ω
 Overload limit; 200mV
 
This is a very elegant, versatile and great performing receiver. Again, as stated above, we have completely gone through this unit, and it performs, sounds and looks great! Really the only cosmetic issue worth noting is a small scratched area;   

Overall, this is an impressive and VERY powerful unit. Very 'Musical' front end. Great detail on top end and punchy low-end. I've experienced many hundreds of receivers and amps over the past 4+ decades, and can just tell instantly when I'm listening to a unit that is more "musical sounding" than others, and this is one of those. Versatile and easy to use.
Measures 21.25" wide x 5.6" tall x 15.6" deep and weighs 33 lbs un-packed. Includes a 30 day limited warranty.
ONKYO TX-6000
Cond. 8.5+
(C) R.R.
SOLD 12/8/2021
SHIPPING TO CHRIS IN NEW YORK

(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 
 

 

         

NEW LISTING 12/17/2021
  (Click on above thumbnails to enlarge photos) 
warranty
FULLY SERVICED / REFURBISHED / WARRANTED
VINTAGE STEREO RECEIVER
PHILIPS AH-7851 STEREO RECEIVER 
#...0815
circa 1977-'81
MADE IN USA! YES REALLY, MADE IN USA!
SOLD 1/4/2022
SHIPPING TO BRIAN IN TENNESSEE

Original Cond; "Balance control had been changed to non-OEM potentiometer (balance knob doesn't fit correctly because of it. Substituted / incorrect, but functioning part also missing a GND terminal). AUX intermittent / low output on Left side. All functions intermittent on L & R. Bias Voltage erratic. AM antenna mounting broken and ant hanging by wires"

ü Our technician has EXTENSIVELY gone through and 'Certified' this unit.

ü We have completely gone through this unit cleaning everything including all switches, controls and contacts. Extensive cleaning of unit internally.

ü All Internal fuses checked for continuity / values and all were correct values fortunately. (We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.)

ü Controls were 'flooded' w/ 'De-OxId' and are quiet

ü We sourced the proper / OEM balance potentiometer control from another Philips receiver we had to install in place of the previously installed, but incorrect replacement pot (replaced prior to coming to us).

ü Found bad / loose capacitor (#C404) in flat-amp / EQ circuit section and replaced with new to rectify 'global' intermittency

ü Found bad PNP transistor (#Q402 / 906. Also sourced from another, Philips OEM receiver circuit board we had) in driver circuit section and replaced with new to rectify 'AUX' intermittency

ü Tuner string checked for any fraying then re-tensioned to increase traction & relieve flywheel binding

ü We aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years and re-centered pointer to correct dial position.

ü 5X dial indicator & meter lamps (#280) have been replaced.

ü We also replaced the heat sink compound which should now be good for another 30 years.

ü Amplifier section had output bias adjusted to service manual spec levels of on both amplifiers

ü NOW both amplifiers have 'even' clipping on 'plus' and 'minus' rails.

ü All inputs tested and both side produces clean and even sine waves into 'brick-wall' 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.
Total restoration time investment 13 hours.

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 72 hours into a 4 Ohm load.
 
ü On our test bench, this particular Philips 7851, #...0815, amplifiers each produced 17 Volts per channel for 36 Watts per channel @ 8Ω via discrete output & 15 Volts per channel for 56 Watts per channel @ 4Ω via discrete TO-3, metal cased transistors; 4x Motorola 7849.
ü AC draw at idle .22A.
ü Floor noise measured at >-74dBm
 ___________________________
   
All original, Milled, Aluminum Philips knobs intact and in near new condition. This is the first one of this model we've had in 24+ years of having the website. Great receiver for 'small-medium' Hi-Fi system, office, project studio or bedroom system.

Philips 7851 Features:
   
- Discrete output transistors
- Huge, Externally located heat sinks (all gear should be designed with this type of heat sink)



- Weighted flywheel analog AM/FM slide-rule tuning
- Separate Bass & Treble EQ
- Dual, Analog 'd'Arsonval' meter for FM tuning and AM signal strength
- Pre-Amp Mono selector
- Stereo / Mono selector for entire pre-amp section (separate from FM selector)
- LED Stereo indicators
- Speaker selector for A - B, A+B, or Off & "Phones" setting
 - "Loudness" function to boost Bass in relationship to other frequencies at lower volume levels for a much fuller sound (careful using this as it's approx a 6dB boost!!!)
- Dual, 'True' Tape Monitors ("True" Tape Monitors can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS® CDR (CD recorders AS WELL AS for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc).
- Phono input with built-in Pre-Amp
- Aux input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS®  etc.)
- 1/4" Stereo Headphone Jack
- Rear located, full barrier strip for external antenna connections
- AC convenience outlet on rear panel un-switched for a capacity of 200 Watts of accessories
  
Original Philips 7851 Specifications:

POWER SPECIFICATIONS:

Power Output; The Philips 7851 has a continuous RMS power output of 30 Watts per channel min. @ 8 Ohms from 20 hertz to 20,000 hertz with no more than 0.1% THD (measured utilizing AUX input)
THD; 0.1% @ 30W, 20-20KHz
Signal / Noise; 90dB
Potential power bandwidth power amp section; 20-20,000Hz
Damping factor; 30 @ 8Ω / 1KHz

PRE AMP SPECIFICATIONS:
Signal / Noise; >90dB @ AUX / Tape
Input Sensitivity AUX / Tape; 150mV @ 47kΩ
Record Out Terminals (RCA); 150mV @ 1kΩ
Separation (AUX); 45dB @ 1KHz
Bass Control; ±12dB @ 50Hz
Treble Control; ±12dB @ 10KHz
Hi Filter; -8dB @ 10KHz
Loudness Control @ -30dB; 
+10dB @ 50Hz & +4dB @ 10KHz
 
TUNER SPECS FOR FM;
Tuning Range; 87.5-108MHz
Freq Response; FCC Limits
Useable Mono Sensitivity / Quieting Characteristics (for 50 dB S/N); 3.5μV
Useable Stereo Sensitivity / Quieting Characteristics (for 50 dB S/N); 42μV
S/N @ 65dBf; > 82dB Mono or 62dB Stereo
Capture Ratio @ 65dBf; 1.7dB
THD Mono @ 1KHz; 0.15%
THD Stereo @ 1KHz; 0.3%
Spurious Noise Ratio; 75dB
Image Response Ratio; 70dB
IF Response Ratio; 90dB
AM Suppression ratio; 40dB
Muting Threshold; 3μV
Stereo Separation @ 1Hz; 45dB

TUNER SPECS FOR AM;
Tuning Range; 540-1605KHz
S/N @ 80dB / m; >45dB
Useable Sensitivity (IHF Bar Antenna); 350uV/mV
Selectivity; 20dB @ 1KHz
S/N; 45dB
Image Rejection; 50dB @ 1KHz
IF Rejection; 45dB @ 1KHz
 
PHONO SECTION SPECS;
Freq Response; RIAA deviation; ±0.5dB
S/N MM; >70dB, (for 10mV output / Shorted inputs)
Input Sensitivity MM; 2.5mV @ 50kΩ
Overload limit MM; 200mV @ 1k
 
Again, we have completely and EXTENSIVELY gone through this, USA MADE



Philips 7851 Stereo Receiver, as stated above and, it's 'certified' and 'Ready To Go'!
This is a very 'musical' and 'warm' sounding receiver. Even the FM tuner has a 'phat' sound compared to many we audition.
Cosmetically, there's just a few 'edge tics' worth mentioning, but certainly nothing distracting (see photos above). The black, anodized aluminum face and knobs are in fine condition. The unit looks fabulous, works and sounds great! Receiver measures 17.5" wide x 13.5" deep x 5.5" high and weighs a heavy, 24 lbs unpacked. Includes our standard 30 day limited warranty.
PHILIPS 7851 STEREO RECEIVER
Cond. 8.5
SOLD 1/4/2022
SHIPPING TO BRIAN IN TENNESSEE
 

(Above text property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)

 

         

          NEW LISTING 12/17/2021
  (Click on above thumbnails to enlarge photos) 
warranty
FULLY SERVICED / REFURBISHED / WARRANTED
VINTAGE STEREO RECEIVER
KENWOOD KR-77 (AKA; TK-66)STEREO RECEIVER 
#...8434
circa 1967-'70
"WORLD AC POWER" ™
M.I.J.
SOLD 4/4/2022
SHIPPING TO STAN IN TEXAS

ü Our technician has EXTENSIVELY gone through and 'Certified' this unit.

ü We have completely gone through this unit cleaning everything including all switches, controls and contacts. Extensive cleaning of unit internally.

ü All Internal fuses checked for continuity / values and all were correct values fortunately. (We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.)

ü Controls (switches / pots) were 'flooded' multiple times w/ 'De-OxId' and are quiet.

ü Tuner string checked for any fraying then re-tensioned to increase traction & relieve flywheel binding.

ü We aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years and re-centered pointer to correct dial position.

ü All dial indicator & meter lamps have been replaced with new.

ü We also replaced the heat sink compound which should now be good for another 30+ years.

ü Amplifier section had output bias adjusted to service manual spec levels of on both amplifiers.

ü Amplifier DC offset to a very low, 2mVDC L&R under load.

ü NOW both amplifiers have 'even' clipping on 'plus' and 'minus' rails.

ü All inputs tested and both side produces clean and even sine waves into 'brick-wall' 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.
Total restoration time investment 12 hours.

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 72 hours into a 4 Ohm load.
 
ü On our test bench, this particular Philips 7851, #...0815, amplifiers each produced 12.25 Volts per channel for 18.75 Watts per channel @ 8Ω via discrete output & 17.75 Volts per channel for 29 Watts per channel @ 4Ω via discrete TO-3, metal cased transistors; 4x NEC 2SD180.
ü DC Offset set to a very low, 2mVDC L&R under load.
ü AC draw at idle .4A.
ü Floor noise measured at >-60dBm
 ___________________________
   
This is the first one of this model we've had in 24+ years of having the website. Great receiver for 'small-medium' Hi-Fi system, office, project studio or bedroom system.

Kenwood KR-77 Features:
   
- Discrete output transistors
- Weighted flywheel analog AM/FM slide-rule tuning
- Separate L&R, Bass & Treble EQ
- Analog 'd'Arsonval' meter for tuning signal strength
- Pre-Amp Stereo / Mono / Reverse selector ('Reverse' mode is great for troubleshooting issues with speakers and room acoustics)
- FM Muting
- FM Stereo indicator
 - "Loudness" function to boost Bass in relationship to other frequencies at lower volume levels for a much fuller sound (careful using this as it's approx a 6dB boost!!!
- Hi filter for reducing the 19KHz pilot tone in FM and tape & AM hiss / electronic hiss
- Low (Subsonic) filter for reducing turntable rumble and sub-frequencies from speakers
- Speaker selector for A - B, A+B, or Off & "Phones" setting
- Pre-Amp In / Power Amp Out loop
- 'True' Tape Monitor ("True" Tape Monitors can be used with Tape decks such as Cassette Tape Recorders/ Players, Reel to Reel's, 8-Track Tape Cartridge Decks, Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS® CDR (CD recorders AS WELL AS for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc) with both RCA and DIN I/O's.
- Dual Phono inputs with built-in Pre-Amps for MM cartridges
- Aux input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRIUS®  etc.)
- 'Tape-Head' input (designed for connecting 'transport only' Reel to Reel tape decks)
- 1/4" Stereo Headphone Jack
- Rear located, full barrier strip for external antenna connections
- Rear located, AC mains protection fuse
- Mono Speaker output via rear located RCA jack in addition to normal, Stereo speaker outputs
- 'Switched' AC convenience outlet on rear panel for a capacity of 60 Watts of accessories
 - True "WORLD AC POWER" 50 / 60 cycles and 110V, 120V, 220V & 240V AC current
  
Original Kenwood KR-77 Specifications:

POWER SPECIFICATIONS:

Power Output; The Kenwood KR-77 has a continuous RMS power output of 20 Watts per channel min. @ 8 Ohms from 20 hertz to 20,000 hertz with no more than 0.9% THD (measured utilizing AUX input).
Total Music Power: 60 Watts / ch @ 4 Ohms and 50 Wpc @ 8 Ohms.
THD; 0.9% @ 20W, 20-20KHz
Signal / Noise; 70dB @ AUX
Potential power bandwidth power amp section; 20-30,000Hz
Damping factor; 23 @ 8Ω / 1KHz
Input Sensitivity AUX / Tape Monitor; 150mV
Input Sensitivity Tape 'HEAD'; 2.5mV
Bass Control; ±10dB @ 50Hz
Treble Control; ±10dB @ 10KHz
Hi Filter; 6KHz
Low Filter; 80Hz
 
TUNER SPECS FOR FM;
Freq Response; 20-20KHz ±2dB
Useable Mono Sensitivity / Quieting Characteristics (for 50 dB S/N); 2μV
S/N @ 65dBf; >60dB Stereo
Capture Ratio @ 65dBf; 2.5dB
THD Mono @ 1KHz / 100% modulation; 0.6%
FM Cross modulation rejection; 80dB
FM Image rejection; 60dB
Stereo Separation @ 400Hz; 38dB

PHONO SECTION SPECS;
Freq Response; RIAA deviation; ±0.5dB
S/N MM; >60dB, (for 10mV output / Shorted inputs)
Input Sensitivity MM; 2.0mV @ 50kΩ
Overload limit MM; 200mV @ 1k
 
Again, we have completely gone through this, late '60's, Kenwood KR-77 Stereo Receiver, as stated above and, it's 'certified' and 'Ready To Go'!
Cosmetically, there's a few scuffs / minor scratches around the Power / Speaker switch and the Vol / Bal pots worth mentioning and some scratches on the top, sheet metal bonnet (likely due to someone having a component without feet sitting on it (see photos above). The unit looks fabulous, works and sounds great!
Includes and e-copy / pdf download of the Kenwood TK-66 (essentially the same as the KR-77, except the KR-77 has 2 MM phono inputs, Power Amp In / Pre-Amp outs and a 'Tape Head' input). Receiver measures 16.5" wide x 12" deep x 5.5" high and weighs a heavy, 23 lbs unpacked. Includes our standard 30 day limited warranty.
KENWOOD KR-77 STEREO RECEIVER
Cond. 8

SOLD 4/4/2022
SHIPPING TO STAN IN TEXAS
 

(Above text property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)


 

    

NEW LISTING 6/17/2021
(Click on above thumbnails to enlarge photos) 
warranty
RESTORED / REFURBISHED / FULLY SERVICED / WARRANTED
VINTAGE AND HUGE KENWOOD STEREO RECEIVER
KENWOOD KR-8010
BIG POWER!
Circa 1978-81
#...1379
MIJ
SOLD 6/19/2021
SHIPPING TO MANUEL IN CALIFORNIA

ü Our technician has completely gone through and 'Certified' this unit.

ü Everything was cleaned inside and out including all contacts, switches and controls (including the typically 'no-access', 'push' switches).

ü All (7X) dial / meter lamps / bulbs replaced for trouble-free service

ü FM Function and FM Stereo indicator replaced for trouble-free service (#25-995)

ü All question-able and common 'stress point' solder joints re-flowed

ü Bias current adjusted to the correct 40mVDC (had drifted to 20!)

ü Tuner has it's original Sanyo LA1231 and LA1240 IC chips

ü NO 'Black Leg' transistors anywhere inside this one...YEA!!!

ü We also aligned the tuner 'front-end' for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years. VERY GOOD TUNER! FM reception incredible, PUNCHY, with GREAT SEPARATION and IMPECCABLY CLEAN!!!

ü Tuner 'Station Indicator / pointer' aligned internally at tuning cap for position accuracy as well

ü Entire unit cleaned / detailed cosmetically inside and out. Receiver looks FABULOUS and NEAR NEW!

ü All inputs tested and both sides produce clean and even sine waves into static 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifiers / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 48 hours and into a 4 Ohm Load!

You will not be disappointed. Total restoration time investment ~11 hours.  

ü On our test bench, the internal amplifiers of this Kenwood KR-8010 receiver, #...1379 produced 36 Volts per channel @ 8 Ohms with 1KHz input for 162 Watts and 26+ Volts per channel @ 4 Ohms with 1KHz input for 169 Watts via discrete, TO-3, metal cased outputs (2x NEC 2x 2SB600 & 2x 2SD555).
ü AC Idle current at 500mA
ü DC offset measures to <25mVDC L/R
ü Bias adjusted to correct spec of 40mVDC.
ü Floor noise @ >-60dBm AC either channel.
   ____________________________

Big and Beautiful, Kenwood KR-8010 (aka; KR-8110) receiver. Classic looking, heavy, brushed-aluminum silver face panel with matching knobs / control caps. Bevel cut dial window really finishes off the elegant look of this series. These are SERIOUS receivers and this one has been 'certified' following the refurb by Oak Tree Vintage and is in great condition!!!
 
Kenwood KR-8010 Stereo Receiver Features:
 
Tuner features:
- Weighted flywheel analog "slide-rule" tuning
- 6-Gang Tuning Capacitor  
- Dual Level FM Muting Selector
- Dual analog 'Signal Strength' and 'Tuning' VU meters
- Built-In, Multi-Directional AM 'Stick / Bar' antenna 

Pre-Amp / 'Control Amplifier' features:
- A, B, A+B, & Off speaker selector
- Three-Band EQ w/ Bass, Mid and Super-Treble controls (may eliminate the need for an external EQ on your speakers since it has a 'Mid' control)
- Tone Defeat for purest signal path
- Super quality de-tented Tone and Volume controls
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound.
- 'Scratch-Filter / Hi filter for reducing tape hiss / electronic hiss & noise and record static
- 100Hz Low Filter built-in to reduce turntable and speaker rumble

Kenwood KR-8010 Inputs:
- Dual Phono / turntable input with Built-In Phono Pre-Amp (with original 'shorting plugs' included to insure noise-free, un-used input)
- Dual tape monitors with Tape monitor 'B' also featuring a DIN input as well as the standard RCA I/O's
(Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / i-gadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- AUX Input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS®  etc.)
- 1/4", stereo headphone jack

- Triple AC 'Convenience' outlets (1x switched / 2x un-switched) with a total capacity of 400 Watts

Other / Build-Quality:
- Pre-out / Main-in loop (allows feed to an additional / larger power amp, or to 'direct feed' the power-amp in the receiver with another pre-amp or audio mixer)
- Easy 'Serviceable' internal design including solvent access to potentiometers

- Multiple "Protection" systems included; Short Circuit Protection for Speaker outputs, Overload Protection for Speaker outputs if receiver / amplifier is driven beyond it's design parameters, DC Surge Protection,   Main Line fuse protection, and thermal protection

- Voltage regulator heatsinks properly 'bolted' down and not left to free-float on the regulator legs

- Huge, Vertical heatsinks for efficient cooling
 
Original Kenwood KR-8010 Specifications (specs):

"The Kenwood KR-8010 has a continuous power output of 125 Watts per channel min @ 8 Ohms, from 20 hertz to 20,000 hertz with no more than 0.03% THD
 
POWER / PRE AMP SPECIFICATIONS:
Output: 130Wpc @ 8 Ohms / 1k & 135Wpc @ 4 Ohms / 1KHz
Dynamic Power Output: 360Wpc @ 4 Ohms
THD: 0.03% @ rated output but typically <0.02% @ half power and @ 8 Ohms
Freq Response of power amp section: 5-100KHz & power bandwidth of 5-70KHz
IMD utilizing AUX: same as THD ratings
Hum / Noise Ratio: 120dB!!! (w/ shorted inputs)
Damping factor: >35 @ 20Hz-20KHz & 8 Ohms
Power Amp Input Level for full output: 1V & 40k Ohms
Tone Control ranges:
Bass: +/-12dB @ 50Hz
Mid: +/-12dB @ 800Hz
Treble: +/-12dB @ 15KHz (this is one of the few I see that doesn't center the 'Treble' all the way up at 20k. MUCH more usable centered at 15k!!!)
Subsonic / Hum / Rumble Filter: -10dB / 18KHz, 6dB/octave
Hi-Cut / Scratch Filter: -10dB / 5KHz, 6dB/octave
Loudness Contour w/ vol @ -30dB: +10dB at 100 Hz
Pre-Amp Input Sensitivity at all inputs except phono & mic: 150mV @ 50k Ohms
Pre-Amp Input Sensitivity for mic: 2.0mV @ 50k Ohms
Max Pre-amp Level Input: 250mV
Pre-amp Output: 1V / 1k Ohms
Tape Output: 150mV @ 1KHz 300 Ohms via RCA jacks
Pre-Amp S/N @ 'Tape' & 'AUX': 105dB w/ 150mV input

TUNER SPECS FOR FM:
Tuning Range: 88-108mHz
Freq Response: 20-15KHz (limited by FCC regulations)
S/N @ 65dBf: >80dB Mono &  >72dB Stereo
Useable Mono RF Sensitivity for 50dB quieting: 14.1dBf / 2.8 μV
Useable Stereo RF Sensitivity for 50dB quieting: 36.3dBf / 36 μV
Useable Sensitivity (IHF): 9.8dBf (1.7μV)
Capture Ratio: 1.0dB
THD @ 65 dBf, Mono: 0.1%
THD @ 65 dBf, , Stereo:  0.15%
IF Response Ratio: >90dB
Spurious Response Ratio: >105dB
Image Rejection Ratio: >85dB
FM Alternate Channel Selectivity: 85dB
AM supression: 60dB
Stereo Separation: ~30dB @ 100Hz, >45dB @ 1KHz & ~30dB @ 15KHz

TUNER SPECS FOR AM:
Tuning Range: 520-1650KHz
Useable Sensitivity (IHF): 250μV/m
Image Response Ratio: 50dB
Signal to Noise Ratio: 50dB
Selectivity: 35dB

PHONO SECTION SPECS:
Freq Response: RIAA Standard curve +/-0.2dB
S/N: >84dB, ref w/ 2.5mV input weighted & >90dB, ref w/ 5mV input weighted
Input Sensitivity / Impedance Phono 1&2: 2.5mV @ 50kΩ (what most cartridges typically are going to be)
Overload limit: 250mV RMS @ 1KHz to not exceed the rated THD of 0.03%

VERY well built


Kenwood receiver, with great features and LOADS OF POWER!
Again, we have completely gone through this Kenwood KR-8010 Stereo Receiver, as stated above and 'certified' it's ready to go!
This is the first Kenwood KR-8010 we've had since one back in 2003!
Cosmetically, other than some scuffs on the tuning knob , the unit is in LIKE NEW condition. Looks like it was unboxed yesterday. Works great and sounds HUGE! Very 'musical' (warm) sounding pre-amp and power amp.
Includes an 'e' copy / pdf download of the Kenwood KR-8010 owners / users / instruction manual. Measures 20.25" wide x 17" deep x 7" high and weighs a HEAVY 45 lbs unpacked. Includes our standard 30 day limited warranty!
KENWOOD KR-8010 STEREO RECEIVER
Cond. 8.5+
SOLD 6/19/2021
SHIPPING TO MANUEL IN CALIFORNIA
(C) R.R.

(Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)
 

    

     
 

NEW LISTING 11/27/2021
(Click on above thumbnails to enlarge photos) 
warranty
RESTORED / REFURBISHED / FULLY SERVICED / WARRANTED
VINTAGE MARANTZ STEREO RECEIVER
MARANTZ 2245 W/ WALNUT WOOD CASE
#...6082
Circa 1971-76
 M.I.J.
SOLD 12/14/2021
SHIPPING TO TROY IN MISSOURI

ü Our technician has completely gone through and 'Certified' this unit.

ü We have completely gone through this unit cleaning everything including all switches, controls and contacts. Also, of course, general cleaning of unit internally.

ü Internal fuses checked for continuity and correct values and fortunately all were correct. (We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.)

ü Power supply circuit adjusted to correct 35VDC output and checked for 'ripple' w/ O-Scope

ü Controls were 'flooded' w/ 'De-OxId' and are quiet

ü Internal Power supply circuit adjusted to correct output and checked for 'ripple' w/ O-Scope

ü DC Offset adjusted on both R&L to 2mV & 1mV!

ü Bias adjusted to correct 10mVDC

ü We aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years.

ü Tuner string checked for any fraying then re-tensioned on Gyro-Wheel to increase traction & relieve flywheel binding

ü Dial pointer re-centered to correct position (after proper tuner, front-end alignment).

ü All dial, "Stereo Indicator" & "Dial pointer" lamps previously replaced with LED's. Source / input Bi-Pins had also been previously / recently replaced. We installed new Meter #25-090 / 8V/250mA lamps. Stereo lamp had previously been replaced as well.

ü We also checked the heat sink compound which should be good for decades.

ü All inputs tested and both side produces CLEAN and EVEN sine waves on Oscilloscope into 'brick-wall' 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 72 hours into a 4 Ohm load.

ü Full Cosmetic detail inside and out including fresh coat of lemon oil on Walnut wood case.

Cosmetically the unit is in amazingly, fabulous shape. Just a few, typical, random scuffs / scratches, most of which weren't even noticeable until we got it under the photo lights (see photos above). The face, knobs and case look good!

While this unit was originally rated at 45 Wpc, on our test bench, both this unit's amplifiers produce 20.5 Volts  per channel for 52+ Watts per channel @ 8Ω via discrete output & 18.6 Volts per channel for 86+ Watts per channel @ 4Ω via discrete, Metal cased, TO-3 outputs. (2x Motorola SJ2513 & 2x SJ2514) 

AC Idle current at 240mA, DC offset output adjusted to a VERY LOW <2mVDC either channel. YES, YOU READ THAT CORRECTLY! "<2mVDC". Bias correctly adjusted 10mVDC @ J754 to J763 TP's (just FYI, original service manual is a 'mis-print' regarding Bias which has them listed as "J753 to J754). Floor noise measured at >-74dBu w/ AUX shorted.)
   ___________________________
 
From the classic and sought after Marantz "Blue-Face" series. The Marantz 2245 Stereo receiver. Beautiful blue dial, behind smoked window, surrounded by handsome, brushed aluminum face with matching aluminum knobs. Beautiful Real Walnut and Walnut veneer, well made clone of a WC-100 case / envelope. Features huge, slide rule analog tuning scale. Very elegant when lit in a darkened room.

Marantz 2245 Features include:
  
- Marantz's "Gyro-Tuning" Weighted flywheel analog tuning
- A (Main), B (Remote), or A+B speaker positions plus "Off" speaker position
- Separate L&R Bass, Mid and Treble controls via concentric knobs and feature high quality de-tented pots
- Hi filter for reducing the 19KHz pilot tone in FM and tape & AM hiss / electronic hiss
- Low (Subsonic) filter for reducing turntable rumble and sub-frequencies from speakers
- FM muting with rear located FM Muting Level control
- Stereo / Mono selector not only for FM, but for entire pre-amp as well
- AUX input for (Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / Smart Phone / MP3 / XM® / SIRUS® etc.)
- True Tape Monitor' (Tape Monitors can be used with Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / Smart Phone / MP3 / XM® / SIRUS® etc. and Dubbing can be used with CDR (CD recorders) units)
- Tape 'Dubbing' / inputs via front mounted 1/4" phono jacks with dubbing capability
 (Tape Monitors can be used with Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPad® / iPhone® / iTouch® / iGadget / Smart Phone / MP3 / XM® / SIRUS® etc. and Dubbing can be used with CDR (CD recorders) units)
- Phono input for standard "magnetic" turntable cartridges
- Loudness control
- Antenna Attenuator for attenuation of strong or bleeding stations
- Front mounted 1/4" stereo headphone jack
- Tuning window features dual large, Analog meters for tuning and signal strength
- FM Quadradial RCA output
- Pre-Amp Out / Main / Power-Amp In loop via standard RCA's (original, Marantz shorting bars installed)
- Rear located, full barrier strip for external antenna connections
- Dual AC convenience outlets on rear panel with 1 switched and 1 un-switched for a total capacity of 300 Watts of accessories
  
 SPECIFICATIONS:
"Rated continuous (RMS) power output per channel, both channels operating simultaneously, 20Hz to 20,000 Hz 45 Watts @ 4 or 8 Ohms."
Comparable Total Music Power: 135 Watts @ 8 Ohms
High Level Hum & Noise: -80dB
Dynamic Range Phono to Rec Out: -80dB
Damping Factor @ 8 Ohms: >45dB
THD: 0.3% THD at full rated power
Freq Response Bandwidth of power amp section; 7Hz-70,000Hz
Line input for 40W output; 180mV
Line input impedance; 100k Ohms
Channel Separation 20-20k; >35dB
 
TUNER SPECS FOR FM;
Freq Response: 50-15KHz (limited by FCC regulations)
RF Sensitivity; 2.3 μV
Selectivity; 60dB
Noise Quieting for 5 μV; -55dB
THD @ 400Hz / 100% modulation: 0.2% Mono & 0.4% Stereo
Subcarrier Rejection: >60dB @ 38KHz
Capture Ratio: ~1.5 - 1.8dB
IF rejection:  > 90dB
FM Stereo separation: >40dB @ 1KHz

PHONO SPECS;
Cartridge input for 40W output; 1.8 μv
Cartridge impedance; 47k Ohms
 
Again, we have completely gone through this receiver. Everything is in great cosmetic condition and unit has been cleaned to near beautiful condition, inside and out! Just a few minor striated areas / scuffs / scratches to mention (see photos above). Really gorgeous in the Walnut cabinet. Looks and sounds great! Very nice looking when lit up at night or in a darkened room! Measures 18.25" wide x 7" tall x 16" deep and weighs an impressive 45 lbs unpacked. Includes our standard 30 day limited warranty.
MARANTZ 2245
Cond. 8.5++
SOLD 12/14/2021
SHIPPING TO TROY IN MISSOURI
(C) R.R.

 (Above text, in it's entirety, property of www.oaktreevintage.com / Oak Tree Enterprises, LLC. See 'Copyright Information' page for details)
 

         

NEW LISTING 6/8/2021
(click on above thumbnails to enlarge photos)
warranty
REFURBISHED / FULLY SERVICED
VINTAGE MARANTZ STEREO RECEIVER
MARANTZ 2252
 #...0183
 Circa 1977-78
 Classic 'Blue Face'
 MIJ
SOLD 6/14/2021
SHIPPING TO SCOTT IN MINNESOTA

ü Our technician has completely gone through and 'Certified' this unit.

ü We have completely gone through this unit cleaning everything including all switches, controls and contacts. Extensive cleaning of unit internally.

ü Internal fuses checked for continuity and correct values. No issues found, fortunately. We don't like seeing incorrect fuses having been installed in a unit as that could mean it had prior issues, or if a fuse value was 'increased' it could have allowed too much current through an 'ailing' circuit causing un-due / un-necessary damage.

ü Previously replaced, and INCORRECT Power switch replaced as well as 'clamping' capacitor as one leg was not letting DC surge protection relay close

ü Power supply circuit adjusted to correct 35VDC output and checked for 'ripple' w/ O-Scope

ü Ungrounded, 2-Prong AC cord replaced with Grounded, heavy-duty, 3-Prong power cord prior to arriving to us

ü Controls were 'flooded' w/ 'De-OxId' and are quiet

ü Internal Power supply circuit adjusted to correct output and checked for 'ripple' w/ O-Scope

ü DC Offset adjusted on both R&L to 0mV+/-0.4mV!

ü Bias adjusted to correct 8mVDC

ü Phono pre-amp originally not working. The tech discovered a burned foil and bad resistor at position R429. Also found transistors; Q405 & Q406 shorted E to B. He replaced ALL 6 transistors in the phono PCB, as well as bad resistors and a couple of electrolytic caps.  


ü We aligned the tuner front-end for optimum AM & FM performance as older internal tuner components have always drifted on vintage gear over the years.

ü Tuner string checked for any fraying then re-tensioned on Gyro-Wheel to increase traction & relieve flywheel binding and re-centered pointer to correct dial position (after proper tuner, front-end alignment).

ü All dial, "Stereo Indicator", "Dial pointer" & meter lamps 'proactively' replaced (7x Dial & Meter 8V/200mA, 1x Stereo Indicator lamp #25-160 / 8V/35mA and 1x Pointer lamp #25-140 / 8V/70mA)

ü We also checked the heat sink compound which should be good for decades.

ü All inputs tested and both side produces clean and even sine waves into 'brick-wall' 8 & 4 Ohm loads! No power supply hum of any kind. It's dead silent! All functions test fine.

ü Following restoration procedures, the unit was run continuously at medium volume, as all our amplifier / receivers are, into a load with "Loudness" on and both Tone Controls at 10 for 72 hours into a 4 Ohm load.

ü Full Cosmetic detail inside and out

Cosmetically the unit is in overall fabulous shape. There's just three or four minor scuffs near the midrange control (see photos above). The balance of the face, knobs and case look good!

On our test bench, this particular Marantz 2252, #...0183 amplifiers each produced 22+ Volts per channel for 60 Watts per channel @ 8 Ω via discrete output & 20+ Volts per channel for 100 Watts per channel @ 8Ω via discrete, "MARANTZ" branded (originals) TO3 Metal Cased outputs (2x 2SA753 & 2x 2SC1343)
AC Idle current at 400mA, DC offset output adjusted to 0mVDC either channel. YES, YOU READ THAT CORRECTLY! "ZERO" mVDC. Bias correctly adjusted to 8mVDC across emitters. Floor noise measured at >-60dBm w/ AUX shorted.)
   ___________________________
   
Classic 'Blue Face' Marantz, 2252 stereo receiver. Elegant looking Face is milled from a solid plank of Aluminum with matching milled aluminum controls. This unit looks great!

Marantz 2252 Features include:
  
- Marantz exclusive "Gyro-Touch" weighted flywheel analog 'Slide Rule' tuning w/ ''PLL' (Phase Locked Loop) circuitry
- A-B, A+B or Off speaker selector
- Separate 'LEFT AND RIGHT' Bass, Mid and Treble utilizing high quality 'Alps' brand pots
- Tone centers selectable for either 100 Hz to 250Hz and 1KHz to 4KHz
- 'Pre-Out' / 'Main-In' loop
 - Built-in Hi filter for reducing 19KHz pilot tone and 38KHz Harmonic in FM broadcasts & Tape hiss.
  - FM muting, separate from FM stereo selector and has adjustable level (on rear panel)
 - Stereo / Mono mode selector for Pre-Amp section or FM tuner (depending on function selected)
- "Loudness" function to boost Bass and Treble in relationship to Mid frequencies at lower volume levels for a much fuller sound
 - Phono / turntable  input
- Aux input (may also be used for Video / CD / DVD /DAT / VCR / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS®  etc.)
- Real 'Tape Monitor Loop' and second 'Tape Input'
  (Tape Monitors can be used with Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc)
- Analog VU 'Tuning' & 'Signal Strength' meter
- Fully shielded tuning capacitor
- Built-In AM 'Stick' antenna
- Antenna attenuator
- 'Quadradial' RCA tuner output (not of much use today)
- 1/4" Stereo Headphone Jack
 - Internally located protection fuse bank
- Separated L & R output heat sink sections featuring large, vertically finned heat sinks
 - Dual AC convenience outlets on rear panel with 1 switched and 1 un-switched for a total capacity of 300 Watts of accessories
  
 Marantz 2252 Stereo Receiver Original Specs:
   "The Marantz 2252 has a continuous power output of 52 Watts per channel @ 8 from 20 hertz to 20,000 hertz with no more than 0.1% THD (measured utilizing AUX input)"
Comparable 'Music' power = 135 Watts
  
POWER / PRE AMP SPECIFICATIONS:
THD: <0.1% @ 8Ω @ full rated power
Freq Response of power amp section;
 @ full rated power 20-20KHz
Dynamic Range; 96dB
IMD utilizing AUX; 0.1% @ 8Ω
Damping factor: >45 @ 8Ω full bandwidth (FYI; almost twice the damping factor of one of it's 'little brothers' the 2220)
 Input Sensitivity: 180mV for output of 52 Watts @ 8 Ohms
Main Power-Amp in: 1.5V for output of 52 Watts @ 8 Ohms
Input Impedance AUX or Tape: 85k Ohms
S/N AUX: 88dB (3dB more than the 2250)
Pre-Amp Out Levels; ref. 180mV @ AUX input = 1.5V
ref. 500mV @ AUX input = 4.2V
Record Out Levels; 180mV
Bass Control;  ±10dB @ 100Hz
Mid Control;  ±7.5dB @ 700Hz
Treble Control;  ±10dB @ 10KHz
Low Filter; 100Hz @ 6dB Oct
High Filter;  7KHz @ 6dB Oct
"Loudness" Contour;  +9dB @ 50Hz, +8dB @ 10KHz (w/ volume set at -30dB)
 
TUNER SPECS FOR FM:
Freq Response: 30-15KHz (limited by the FCC)
Useable Mono RF Sensitivity for 50dB quieting: 17.3dBf / 4.0 μV
Useable Stereo RF Sensitivity for 50dB quieting: 37.2dBf / 40 μV
Capture Ratio: 1.5dB @ 45dBf
THD w/ 100% modulation @ 1000Hz, Mono: 0.15%
THD w/ 100% modulation @ 1000Hz, Stereo:  0.3%
Spurious Response Rejection: 90dB
Image Response Rejection: 70dB
I.F. Rejection: 95dB
Alternated Channel Selectivity: 70dB
AM Suppression: w/ 1000μV = 50dB
19KHz Subcarrier Rejection: 60dB

TUNER SPECS FOR AM;
S/N; >49db
Useable Sensitivity; 20μV / m with external antenna
Alternate Channel Selectivity; 46dB
I.F. Rejection; 40dB
Image Response Rejection; 45dB
 
 PHONO SECTION SPECS:
Freq Response: 20-20KHz (typical RIAA is limited to 30Hz to 15KHz)
Input Sensitivity: 1.8 mV @ 47kΩ
Dynamic Range: 96dB!!!
S/N Phono: 76dB!!! (typical would be about 68dB and a dB more than the 2250)
Overload: 100mV @ 1KHz
  
Again, as stated before, we have completely gone through this Marantz 2252 Stereo Receiver cleaning and testing all and it gets our full certification. Brushed aluminum face and all original, milled knobs in fabulous shape. After restoration, receiver looks, performs and sounds great! This is a VERY 'Musical' sounding tuner/pre/power-amp. Very 'full, warm and phat'. Great 'low-end' depth at any volume. Tone controls have a lot of influence. Overall a pleasing unit to listen to in all aspects. Measures 17.25" wide x 14.4" deep x 5.5" high and weighs 31 lbs unpacked. Includes our standard 30 day limited warranty!
MARANTZ 2252 STEREO RECEIVER
Cond. 8.5++
SOLD 6/14/2021
SHIPPING TO SCOTT IN MINNESOTA
(CONS. R.R.)

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