Studer Revox A 77 CH1 Analog Tape Recorder

The ReVox A 77 was introduced in 1967 and replaced the A-G 36 series. It no longer contained tubes, but only transistor technology and a new circuit technology. The unit was launched in a series of four main versions: Mk I- IV, as well as many special versions for different applications. In total, ReVox supplied 186 different versions of the A77, including different speed and track versions, Dolby B noise cancellation, for studio use with balanced audio inputs and outputs at speeds of 19 and 38 cm/s (ReVox A77 ORF). The ReVox A76 tuner, the ReVox A78 amplifier, the dynamic microphone type 3377, which Beyerdynamic manufactured for ReVox, and a cable remote control were also included.  
Between 1967 and 1977, over 450,000 units were sold, making the A 77 one of the most successful tape recorders. Production ended with the successor model B 77, which was introduced in 1977.

Technical data

Drive: 3 Papst outrunner motors
Electronically controlled capstan motor
Belt speeds: 9.5 cm/s and 19 cm/sas a special version also with 19 cm/s and 38 cm/s
Pitch fluctuations:
at 19 cm/s better +/- 0.08%,
at 9.5 cm/s better +/- 0.1%
Frequency response across band:
30 Hz to 20 kHz + 2 dB to - 3 dB at 19 cm/s
30 Hz to 16 kHz + 2 dB to - 3 dB at 9.5 cm/s
Signal-to-noise ratio:
66 dB (2-track), 64 dB (4-track) at 19 cm/s
63 dB (2-track), 59 dB (4-track) at 9.5 cm/s
with Dolby:
67 dB (2-track), 65 dB (4-track) at 19 cm/s
64 dB (2-track), 62 dB (4-track) at 9.5 cm/s                                               
Spooling speed: approx. 8 m/s
Electronics:(Portable device) 54 transistors, 32 diodes, 4 silicon rectifiers, 1 photoresistor, 4 relays
Even back then, the information was incomprehensible to most users!
Power consumption: approx. 70 - 100 VA
Weight: 15 kg
Mass: 41.5 x 35.9 x 18.0 cm