Technical Details
Brand: Revox
Model:A77
Category:Mid High Fidelity
Application:Consumer
Electronics:Solid State
Equalization:NAB , IEC
Country of Manufacture:Switzerland
Release dates:1967 - 1977
Original Price: $799
Tracks:1/4 Rec/PB
Speeds: 1 7/8, 3 3/4, 7 1/2, 15
Max Reel Size("): 10.5"
Number of heads: 3
Dimension: 15½ x 16 x 7 in - 415 x 359 x 180mm
Head Composition: Permalloy
Head Configuration: Stereo
# Motors: 3
Auto Reverse?:No
Voltage(s): 110-120v, 220-240v
Outputs: RCA
Frequency Response:30Hz - 20kHz @ 7½ ips
Wow and Flutter:.08% at 7½ ips - .1% at 3¾ ips
Signal-to-Noise Ratio: 58 dB at 7½ ips - 56 dB at 3¾ ips
Sound quality rating:7 / 10
Long-term reliability rating: 9/ 10
Weight: 34 Lbs. (15.5 kg)
Additional Details
Description
The A-77 was the first solid-state machine produced by Revox and had a remarkably long production run that featured four different variations
MK I (1967), MKII (1968), MK III (1971) and MK IV (1973)
The definitive reel to reel of the late 1960s – early 70’s. You couldn’t walk into a radio station or recording studio without seeing at least one….
First produced in 1967 the A77 was a true semi-professional recorder. Solenoid controlled 3 Motor transport with electromagnetic braking , 10½” reel capability, three heads, NAB/IEC equalization, servo-capstan drive and a choice of 15 and 7½ ips or 7½ and 3¾ ips. 1 7/8 ips was also available for utility applications. The rugged three-motor design and easy tape handling made these machines a hit in the late sixties and many found their way into radio stations and recording studios where some are still doing service.
Additional Info
Early-production models of the A-77 had a few issues –
Nylon brake shoes, which were soon replaced with cotton-pad brakes for smoother transition between functions.
Early models were prone to excessive heat from the motors.
Restoration Article with good Pics
Distortion at full modulation: 2% at 7½ ips and 3% at 3¾ ips (maximum) / Crosstalk: mono better than 60 dB, stereo better than 45 dB / Bias frequency: 120kHz, push-pull / Semiconductors: 54 transistors, 32 diodes, 4 silicon rectifiers, 1 photo resistor / Rewind speed: 62 seconds for 1200 ft / Audio output power: 2 x 10 watt plug-in optional amplifier boards / Inputs: Mic (switchable) low: 50 – 600 ohm, 0.2 mV. high: 100 Kohm, 2mV Radio: 2 mV 33 Kohm), Auxiliary: 40 mV 1 Mohm) / Outputs: line: 2.5 V / 600 ohms (max). radio 1.2 V / 2.5 Kohms (max) / Speaker(s): four with suitcase model only / Dimensions: 14½ x 16¼ x 7″ (388 x 413 x 178 cm) / Weight: approx. 34 lbs (15.5 kg) / half-track stereo with quarter-track version released in 1968