Nakamichi System-One // Vintage Stereo System // 620 Amplifier / 630 Preamp-tuner / 600 II Cassette Deck / Timer

The Nakamichi System One is peak late-’70s Japanese hi-fi cool—a beautifully matched separates system that shows just how serious Nakamichi was about sound long before they became cassette legends. Designed as a cohesive stack rather than random components, System One delivers a sound that’s clean, dynamic, and effortlessly musical, with that unmistakable Nakamichi precision and refinement. Everything feels intentional: the minimalist industrial design, the silky controls, and the way the system presents music with clarity and balance rather than brute force. It’s understated, elegant, and quietly confident—hi-fi that doesn’t shout, but absolutely knows what it’s doing. A true collector’s setup that captures Nakamichi at the moment they were becoming something special.

This system was designed to use a single stereo amp. Instead of closing that space with the metal cover that it came with, we decided to put a second (non-functional) amp in its place... because it just looks cooler :) And great as a parts unit for the working amp.

Production

1975-79

Condition

9/10

Serial No.

1101616 / 4201365 / 02401 / 4102071 / 4105352

Orig. MSRP

$1850

Restoration

• 2 new large power supply caps in the working 620 amp
• Re-glued pot knobs as necessary
• Verified radio tuner and associated functions
• Right channel was out on the tape player, opened it up and Tom worked his magic; no issue since.
• Re-installed all units back in rolling rack

• Tested together all good, (except the 2nd broken/irreparable stereo amp on the bottom, obviously).

   

  For the cassette deck:

   

• Replaced belts and idlers
• Replaced "Tape" switch
• Burnished contacts on Record/Play switch
• Adjusted azimuth
• Adjusted record and tape bias
• Cleaned tape path
• Adjusted speed
• Cleaned control contacts

Factory Specs

The System One is a unique concept.The unitizing of a group of no-compromise products to form a nucleus around which an ultimate music system can be built is a concept several years ahead of its time, and clearly Nakamichi. The System One Rack with built-in Program Timer is simple to assemble and enjoy. The included Program Timer is a sophisticated device capable of many functions. It is the result of the latest MOS IC technology and features all-electronic control as well as an LED type display. The timer allows unattended recording of radio broadcasts and sleeping or waking to radio or tape in addition to functioning as a very accurate digital clock.

 

620 AMPLIFER

Power output: 100 watts per channel into 8Ω (stereo)

Frequency response: 5Hz to 100kHz

Total harmonic distortion: 0.005%

Damping factor: 100

Signal to noise ratio: 120dB

Semiconductors: 3 x ICs, 46 x transistors, 41 x diodes

Dimensions: 15.75 x 7.44 x 9.76 inches

Weight: 27.56 lbs

 

630 FM TUNER PREAMPLIFER

Frequency response: 20Hz to 50kHz

Total harmonic distortion: 0.004%

Input sensitivity: 2mV (MM), 100mV (line)

Signal to noise ratio: 80dB (MM), 100dB (line)

Output: 400mV (line), 1V (Pre out), 5V (Pre out MaxDimensions: 15.75 x 6.69 x 9.33 inches

Weight: 15.43 lbs

 

6OO II CASSETTE DECK

Type: 2-head, single compact cassette deck
Heads: 1 x Record/Playback (Crystalloid Super Head), 1 x Erase
Tape Speeds: 4.8 cm/s (3-3/4 ips)
Tape Types: Type I (Normal), CrO2 (Chrome), Metal
Noise Reduction: Dolby B, Dolby C
Frequency Response: 20Hz - 20kHz (Metal tape)
Signal-to-Noise Ratio (S/N): 68dB (Dolby C) / 70dB (Dolby C)
Wow & Flutter: 0.06%
Total Harmonic Distortion (THD): ~1.0% - 1.2%
Motors: 1 x Reel, 1 x Capstan, 1 x Mechanism
Features: Manual Tape Type Selection, Manual Record Level/Bias, Test Tone Generator, 4-Digit Counter, Auto Stop. 

The History of Nakamichi

Nakamichi was founded in 1948 by Mr. Etsuro Nakamichi, starting from a small research institute in Tokyo, Japan that provided R&D for major brands, government entities, universities and organizations. Since then, it has established a reputation for high-end source components, like tape decks and CD...
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Liner Notes

Nakamichi's 620 Complete Mirror design brings a level of performance to class B amplifiers that was formerly associated only with class A amplifiers.The 620 is closer to a pure class B amplifier than anything else that has gone before. The first stage of the 620 is a differential amplifier with "current mirror" loading. The final section of the amplifier is a four stage push-pull circuit.All four stages are full complementary direct coupled, and each stage employs a unique double NPN/PNP combination for the positive and negative halves. This design eliminates the errors inherent in even the most carefully matched pairs of NPN/PNP output devices. These errors, furthermore, are eliminated without the use of bias diodes, bias adjustments and high idle currents. The 620, in fact, idles at approximately 1/20 the current of conventional class B power amplifiers of comparable output power. This new approach takes full advantage of class B efficiency with the freedom from switching and crossover distortions that was once thought possible only with class A amplifiers.

 

The 600Ⅱ is an updated version of the Nakamichi 600 two head cassette console, and was produced from 1978 to 1979. The 600Ⅱ uses a new crystalloid super head with a 0.9 micron gap, which allows recording and playback at 20 kHz. Other features include Dolby B noise reduction, a 19kHz multiplex filter for FM radio recording, Type Ⅰ and Ⅱ (EX, SX) tape selection with manual record and bias adjustments, and test tone generator. It uses a precise mechanical transport with a sensor for tape end auto-stop, is capable of auto-play on power on, has a memory stop function, and will also stop and release the transport on power-off.

Stock No.

9257407414493