('80-'82) 33 WPC  $350

In excellent cosmetic condition, fully serviced and fully tested, this Mitsubishi DA-R7 was obtained from the original owner.  If you're not familiar with Mitsubishi electronics of Japan, this excellent stereo receiver may catch you off guard.
While most folks might think of the car brand when they hear the name "Mitsubishi", to some "audiophiles", Mitsubishi might not pop up on their HiFi radar.  While they weren't the best known name in high fidelity stereo gear during the '70's, they were well established in Japan with a solid reputation a for leveraging their expertise in high-end separate component design.  This applied specifically when it came to the design of the DA-R7 along with all of their receiver and amplifier models.  

Rather than compromise on critical circuits, they reduced costs by cleverly eliminating non-essential features.  Similar to Yamaha's "natural sound" receivers, the DA-R7 has a very flat frequency response curve. If you like true reproduction of sound without coloration then you might like its sound.  Of course, the choice of speakers has a whole lot to do with the actual output of sound for any receiver or amp.

Mitsubishi's goal was to build a receiver with the performance of separate units costing much more. To do this, they used proven circuit topologies and quality parts from their separate component models. While not inexpensive compared to other receivers at the time, the DA-R7 delivered high performance and value at a reasonable cost.

This sweet DA-R7 receiver is very well built and should be considered a perfect anchor for most any entry level stereo system.  Among its many cool design features are it's rack handles, distinctive rotary tuner dial and beefy steel faceplate that gives it a very handsome and industrial look.  Even the knobs and switches have a beautiful brushed metal design.  And the stunning rosewood veneer case adds to the overall appeal; we would describe the DA-R7 as a unique and gorgeous piece of excellent Japanese vintage design history.

The DA-R7 is very conservatively rated at 33 watts per channel into 8 ohms and 42 watts per channel into 4 ohms.  It can easily drive two pairs of efficient speakers.The frequency response of 20Hz to 20kHz is delivered via all inputs and outputs in a clean, noise free manner.  And, with a THD of a very low 0.01%, it's right up there in build quality with many of the other well known names at the time.

When it came to the tuner design, The DA-R7 incorporated a sophisticated tuning mechanism that allowed precise frequency selection across the FM band. The unique tuning knob takes 15 full rotations to traverse the entire FM spectrum, enabling tuning resolution down to 100 kHz increments.  

With its distinctive styling, robust build quality, and high-quality phono stage it's a no brainer for us to admit that this classic stereo receiver by Mitsubishi of Japan is also one of the best looking units we've seen when compared to the myriad of units that have come and gone over the years..

Basic specs:
Dimensions: 18.5"W x 7"H x 17"D
Weight: 23 lbs

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receiver ('76-'78) 120 WPC  $2200  (partial recap / restored)

In excellent cosmetic condition, this Pioneer SX-1050 is rated at 120 watts (RMS) per channel into 8 ohms and 170 watts (RMS) into 4 ohms. 

Services performed in January 2024:
This powerful beauty has been completely disassembled for a complete and painstaking servicing.  All the output transistors, driver transistors and diodes in the right channel amp circuit were replaced.  Both left & right channel power amp circuits were recapped.

The protection relay was removed and the relay contacts were cleaned.  The entire front panel switches and pots were thoroughly cleaned and deoxit was applied.  After reassembly, it has been thoroughly tested.   All the inputs, outputs, switches, knobs and lamps are working correctly.  Service data sheets and parts included.

Except for a difference in power output, all of the features in the SX-1050 are the same as the SX-1250 including:

Massive toroidal transformerStep attenuator volume controlMassive power supply with "step-start" circuit

From Pioneer's brochure:
"High sensitivity, outstanding circuit design in a new AM/FM receiver.  The Pioneer SX-1050 puts every significant AM/FM receiver feature together in a strikingly handsome package.

From a highly sensitive FM front end, a high selectivity IF section, to the low distortion, big power amplifier section that delivers the outstanding continuous power output of 120 watts per channel min RMS at 8 ohms from 20 to 20,000Hz, with no more than 0.1 % total harmonic distortion, the SX-1050 radiates the excellence that the stereo buff has come to expect from Pioneer electronics.

Such features as a phase locked loop IC in the MPX section, the audible multipath switch that helps eliminate FM wave interference, and the highly advanced equalizer section are not just extra touches in this receiver, but exemplify the considerable thought that has been applied to the overall design and circuit of the SX-1050.

Other important contributions to flawless sound include the Pioneer Twin Tone Control, the Toroidal-core transformer, the two very large capacitors in the power supply section - all calculated to reproduce the sound spectrum with stability amid full component protection in the inimitable Pioneer style."

Basic specs:
Power output: 120 watts per channel into 8Ω (stereo)
Frequency response: 10Hz to 50kHz
THD: 0.1%
Dimensions: 21"W x 6.8"H x 17.8"D
Weight: 52 lbs

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 receiver ('78-'81)  80 WPC  $500

Designed and built in Japan during the 70's, this rare, attractive and well built Project/One Mark 800 receiver is cloaked in mystery due to the many *rumors about the origins of the brand itself.  The receiver's original MSRP was about  $599 in 1978.  

Suffice to say that when viewed in person, the Mark 800 appears to be a closely designed Pioneer-style copy but it's not;  while the cosmetics may look similar to Pioneer, the internals are more closely aligned with Hitachi.
There is easy access to the boards featuring neat wiring assemblies and generous high quality caps along with Alps switches.  Good stuff! *NOTE: (for accurate info about the origins and background see the section below "About Project/One").

On this Mark 800, a simple spin of the heavily weighted tuning knob is like a smooth flywheel that glides the dial pointer along across and behind the crystal clear glass.  The heavy solid metal knobs and switches are also of top shelf design.  

This is a large receiver in comparison to most of the mid-level units of the era. It measures 21" wide x 20" deep x 7" high and weighs about 42 lbs.  The real walnut veneer case is sculpted on both front sides.  The heavy aluminum faceplate is pristine.  There are pre-out / amp jumpers on the back so it can be used as a standalone amp or preamp.

Bias is set and all the functions on this unit are working perfectly.  Although the Mark 800 is rated at 80 WPC (8 ohms) and 95 WPC (4 ohms) actual measured output is about 92 watts per channel in 8 ohms and close to 100 watts per channel in 4 ohms.  

The Mark 800 has connections for two turntables, three pairs of speakers, aux and two tape inputs.

Unfortunately, as in almost all Project/One units, the meters are sketchy (defective) at best.  We solved that problem by using a modern set of backlit power meters sitting on top of the case.
NOTE: The Project/One audio designers sourced all their meters from another Japanese company that subsequently went out of business in the early 80's.  In a pinch, it's been claimed that meters from the Pioneer SX-XX80 series have been known to work as replacements with a little "minor surgery".

Note: This Project/One Mark 800 receiver is identical to the Telefunken TR-800 receiver that appeared in Germany during the same era with the only difference being the black faceplate on the Telefunken.  This only added more mystery to the history of Project/One units.

Specs:
Power Output:  80 WPC w/ 8 Ohm, 20 Hz to 20 kHz (95 WPC w/ 4-ohm)
Rated THD: 0.1%
Frequency Response:  Phono, RIA±1 dB
HighLevel 10Hz to 35kHz, ±0.5 dB.
High 8 or 12 kHz (12dB/octave)
Low 15 or 30 Hz (12dB/octave)
Original MSRP: $599.00 (1978)

About Project/One and Playback Electronics...
Around 1969, Radio Shack's parent company Tandy Corporation purchased Allied Electronics. A few years later the courts made Tandy divest itself of Allied and it was sold to Shaak Electronics. One of Allied's main players, Shelby Young and a group of his top management people left and started the Playback store chain in 1972.  At the time, Playback was just another division of Hydro Metals, a company that owned GC Electronics, a manufacturer of electronic parts and accessories that was a major supplier to Allied. When Tandy took over Allied they replaced most of the GC inventory with the Radio Shack brand. However, Playback used GC for most of their accessories.

According to some of the people who actually worked at Playback, rumors that the Project One receivers were made by Pioneer was started by someone at Playback.  Salesmen were telling customers that it was Pioneer and corporate would neither confirm or deny the rumors.  However, according to the actual technicians at Playback (the guys that actually opened them up and worked on them) the Project/One line looked to have been manufactured by Matsushita (Technics).  It's no secret that Matsushita was the largest Japanese manufacturer of electronics at that time anyway.  Even today in 2021, when nosing around inside the Project/One gear (especially the receivers) there's nothing remotely connected to Pioneer.  The bottom line regarding Project/One was that they were reliable performers. As with most Japanese Audio of the day, they did exhibit that tell-tale upper-midrange edginess, so difficult to eliminate in even the best audio of that time, and even today.

About "house brands"...
In earlier days, it was simple to regard stereo receivers as being in two distinct classes: Those manufactured by major, well known companies and those manufactured by lesser known makers under contract to retail chain stores. Today, it is almost impossible to distinguish between these two receiver categories, as some of the retail chains of audio dealerships had grown to the point where they could hire the engineering and production facilities of highly qualified high-fidelity component manufacturers. In fact, it was rumored that many of the "name brand" manufacturers also produced "private label" sets for such retail outlets. The Project/One brand is one that was developed for the Playback, Inc., retail outlets based in and around the Chicago area.

At one time, during the 70's and 80's, there were many HiFi shops and electronics chain stores all over the country.  The West Coast was dominated by three large chain stores (and we worked at two of them back in the day). There was Pacific Stereo (Concept and Reference models) and University Stereo and, finally, Federated Electronics.

There were a few other smaller outfits while the Midwest (mostly Chicago) was covered by the "Playback" chain of stores (their motto was "the electronics playground").  Besides the usual big names (Pioneer, Sansui, Yamaha, etc) Pacific Stereo, University Stereo, Federated and Playback also had their own house brands.  At Playback, Project/One was their top tier line (followed by the Skanda, and Kingsway models).

Most of the very early Project/One receivers were built by Matsushita (Panasonic/Technics) and rebranded by Playback.  Hence, today, some of the better receivers like the Mark IV and Mark IIIB and others are now considered very collectible and are beginning to command high prices.  As the mid-70's rolled out and the competition became fierce, Project/One equipment (tape decks, turntables, etc) were eventually sourced to other Japanese suppliers Often confused with the other "ProJect" brand are the high end turntables currently made in Czechoslovakia.  Project/One however is a completely different brand with no connection whatsoever.

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('76-'78) 32 WPC    $300

This Yamaha CR-450 is in pristine cosmetic and operating condition.  It was part of the excellent "CR" design series from Yamaha.  The CR-450 replaced the earlier CR-420 and CR-400. The entire lineup was just flat out gorgeous.  Besides our usual intensive bench servicing that includes all pots/switches/bias and new diodes on the board that controls the lighting. 

The conservative rating of 32 watts per channel into 8 ohms was  more robust than the later CR-420.  Power output is actually closer to 35 WPC and the output into 4 ohms is about 38 WPC.Packed with all discrete components, it's late 70's design reflects the rapid improvement in receivers that made them lighter, more powerful and relatively easy to work on.  

Yamaha's famous "Natural Sound" is part of the attraction in the CR-450, along with the loudness compensation feature that made the Yamaha CR Series unique.  Perhaps "natural sound" is best described as having a neutral sound stage with less emphasis on colorization to the music. Of course, as usual, it's always about the quality and efficiency of the speakers but the natural sound has always been part of Yamaha's legacy.  Something else that's unique to this Yamaha series is the OTS (Optimum Tuning System), which is an easy-to-use feature that automatically locks in the exact center of the tuned channel - for the lowest possible distortion.  Stereo Review magazine once said (and still applies today) "the muting and OST systems operated flawlessly and the harmonic distortion of the CR-450 was so low that without the most advanced test instruments it would have been impossible to measure it."

Among Yamaha's most significant features is the *continuously variable loudness control. By using this control, the frequency balance and volume are adjusted simultaneously to compensate for the ear's insensitivity to high and low frequency sound at low volume settings. Thus, you can retain a natural-sounding balance regardless of listening level.
*NOTE: How does Yamaha's Loudness control work?
Theoretically, the degree of loudness compensation should vary with the listening level: The greater the reduction from "real" sonic levels, the greater the compensation. In the Yamaha CR-420, you first turn up the loudness all the way and set the volume control to the highest listening level you'd be likely to want, which will, of course, depend on your taste, the efficiency of your speakers and the acoustics and size of your room. For subsequent level adjustments, turn down the loudness, which boosts the lows and, to a smaller extent, the extreme highs relative to the midband to maintain a natural sounding balance.

When it comes to the Yamaha CR-450, all this adds up to a lot more than most could logically expect of the "low man on Yamaha's receiver lineup totem pole", even in view of their minimum performance standard policy. The tuner section is several cuts above the conventional. The phono preamp is eminently quiet, the flexibility of the rest of the preamplifier section is also impressive.  Essentially, the Yamaha CR-450 was unique in its price range. 
Main features are the outputs for two pairs of speakers, phono, FM, Aux (perfect for streaming) tape in/out.   The teak veneer case is flawless and the brushed aluminum faceplate is literally mint!

SPECS:
Power output: 32 watts per channel into 8 ohms
Frequency response: 20Hz to 20kHz
THD: 0.05%
Speaker load impedance: 4Ω (minimum)
Dimensions: 13.1"D x 6.5"H x 18.3"W
Weight: 21 lbs

('78-'80) 22 WPC    $300

Obtained locally from the original owner, this Yamaha CR-420 is in pristine cosmetic and operating condition. 

The CR-420 is part of the "best" design series from Yamaha that included the 620, 820, etc. They were all just flat out gorgeous.  Besides our usual intensive bench servicing that includes all pots/switches/bias, it also has all new lamps and new diodes on the board that controls the lighting.  The conservative rating of 22 watts per channel into 8 ohms is closer to 25 WPC and the output into 4 ohms is 30 WPC.

Packed with all discrete components, it's late 70's design reflects the rapid improvement in receivers that made them lighter, more powerful and relatively easy to work on.  

Yamaha's famous "Natural Sound" is part of the attraction in the 420, along with the loudness compensation feature that made the Yamaha CR Series unique.  Perhaps "natural sound" is best described as having a neutral sound stage with less emphasis on colorization to the music. Of course, as usual, it's always about the quality and efficiency of the speakers but the natural sound has always been part of Yamaha's legacy.  Something else that's unique to this Yamaha series is the OTS (Optimum Tuning System), which is an easy-to-use feature that automatically locks in the exact center of the tuned channel - for the lowest possible distortion.  Stereo Review magazine once said (and still applies today) "the muting and OST systems operated flawlessly and the harmonic distortion of the CR-420 was so low that without the most advanced test instruments it would have been impossible to measure it."

Among Yamaha's most significant features is the *continuously variable loudness control. By using this control, the frequency balance and volume are adjusted simultaneously to compensate for the ear's insensitivity to high and low frequency sound at low volume settings. Thus, you can retain a natural-sounding balance regardless of listening level.

*NOTE: How does Yamaha's Loudness control work?
Theoretically, the degree of loudness compensation should vary with the listening level: The greater the reduction from "real" sonic levels, the greater the compensation. In the Yamaha CR-420, you first turn up the loudness all the way and set the volume control to the highest listening level you'd be likely to want, which will, of course, depend on your taste, the efficiency of your speakers and the acoustics and size of your room. For subsequent level adjustments, turn down the loudness, which boosts the lows and, to a smaller extent, the extreme highs relative to the midband to maintain a natural sounding balance.

When it comes to the Yamaha CR-420, all this adds up to a lot more than most could logically expect of the "low man on Yamaha's receiver lineup totem pole", even in view of their minimum performance standard policy. The tuner section is several cuts above the conventional. The phono preamp is eminently quiet, the flexibility of the rest of the preamplifier sec- tion is also impressive.  Essentially, the Yamaha CR-420 was unique in its price range. 

Main features are the outputs for two pairs of speakers, phono, FM, Aux (perfect for streaming) tape in/out.  It also has all new incandescent lamps including the light that travels with the tuning needle up and down the dial.
The teak veneer case is flawless and the brushed aluminum faceplate is literally mint!

Specs:
Power output: 25 watts per channel into 8 ohms
                     30 WPC into 4 ohms
Frequency response: 20Hz to 20kHz
THD: 0.05%
Speaker load impedance: 4Ω (minimum)
Dimensions: 12.8"D x 6.5"H x 17.8"W
Weight: 20 lbs

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