Revox B 77

General

The Revox tape machine B77 has famous ancestors. The successful A to G36 series changed the then young world of magnetic recording as early as 1954. The successful A77 series has been running in quantities of over half a million since 1967; it can be found in tireless use from the tropical rainforest to the Antarctic.

Experience in building professional equipment has taught STUDER REVOX to be at the forefront of technology - preferably years ahead. Revox units run and retain their value for years, even decades.

Data

General

• Manufacturer: Revox
• Model: B-77
• Years of manufacture: 1977-1982
• Manufactured in: Germany, Löffingen
• Color: Nexel-coated (gray)
• Remote control: optional
• Dimensions: 452 x 414 x 207 mm (WxHxD)
  • Dimensions with 26.5 cm coils:
    • largest width 538 mm, largest height 463.5 mm
• weight: 17 kg
• original price approx.: 2'200 DM
  • Option dust cover: 100 DM

Option remote control: 250 DM

• • Option retrofit unit for slide projection: 500 DM

Connections

• Microphone: 0.15 mV / 2.2 kOhm
• MIC (asymmetrical): for microphones from 50-600 Ohm
• LO position: jack plug 6.3 mm

• Microphone: 2.8 mV / 110 kOhm
• MIC (asymmetrical): for microphones from 50-20 kOhm
• HI position: jack plug 6.3 mm

• Radio
  • 2.8 mV / 20 kOhm
  • Plug: 5-pin according to DIN
• AUX

40 mV / 220 kOhm

• • Connector: Cinch
• Overload resistance of all inputs: 40 dB (1:100)
• Outputs, per channel (level at 0 VU +6 dB resp. 514 nWb/m)
  • Output
    • 1.55 V/ Ri 390 Ohm, max. 1.5 kOhm
    • adjustable with level control, max. -26 dB
    • Connector: Chinch

Radio

• • • 1.55 V/ Ri 390 Ohm, max. 4.7 kOhm
    • adjustable with level control, max. -26 dB
    • Plug: 5-pin according to DIN

Phones (headphones) (2 ×) max.5,6 V/ Ri 220 Ohm short-circuit proof, optimal for headphones 200-600 Ohm Plug stereo jack, 6.3 mm

• Other connections

Remote control with drive functions Remote control varialble tape speed

• • Slide projector or cross-fade unit (retrofittable)

Technical data

• Motors
  • Three-motor drive, 2 AC winding motors; 1 AC capstan motor, electronically controlled(direct drive)
• Belt speed
  • 19 cm/s and 9.5 cm/s, electronically switched. Tolerance of target speed ±0.2% (with external add-on: variable speed 6.5-28 cm/s, with built-in speed control on MK II: ±10%).

Slip

• • max. 0.2 %
• Pitch fluctuation
  • (according to DIN 45507)
  • at 9,5 cm/s better than 0,1 %
  • at 19 cm/s better than 0.08 % * coil size
• Coil size
  • up to 26.5 cm (10.5 in.) diameter (minimum core diameter 6 cm). Tape tension switchable (for small core diameters)
• Rewinding times
  • approx. 135 sec. for 1100 m tape
• Uninterrupted playing time
  • With long playing tape 1100 m
  • 3 hrs. 12 min. at 9.5 cm/s
  • 1 hr. 36 min. at 19 cm/s
• Counter
  • 4-digit counter
• Drive control
  • Integrated logic for arbitrary function transitions with belt run sensor, motors contactless, electronically switched. All functions remote controllable. Timer operation with remote control possible.
  • Audio electronics
• Equalization
  • (according to NAB)
  • 9.5 cm/s: 90 µsec / 3180 µsec
  • 19 cm/s: 50 µsec / 3180 µsec
• Frequency responses
  • (measured over band, at -20 VU)
  • at 9.5 cm/s
    • 30-16,000 Hz +2/-3 dB
    • 50-10,000 Hz ±1.5 dB
  • at 19 cm/s
    • 30-20,000 Hz +2/-3 dB
    • 50-15,000 Hz ±1.5 dB
• Full scale
  • 514 nWb/m corresponds to 6 dB above 0 VU
• Level meter
  • VU meter according to ASA standard, with LED overdrive indicators

Distortion factor (referred to Revox 631 Mastering Tape, 2-track)

• • at 0 VU (257 nWb/m)
  • at 9.5 cm/s <0.5 %
  • at 19 cm/s <0.2 %
  • at 0 VU (514 nWb/m)
  • at 9.5 cm/s <1.5 %
  • at 19 cm/s <0.5 %
• Noise-to-voltage ratio(measured over band according to ASA-A).
  • 2-track:
    • at 9.5 cm/s >64 dB (A)
    • at 19 cm/s >67 dB (A)

2-track:

• • • at 9.5 cm/s >60 dB (A)
    • at 19 cm/s >63 dB (A)
• Crosstalk attenuation
  • (at 1000 Hz)

Stereo >45 dB Mono >60 dB

• Cancellation attenuation
  • at 19 cm/s >75 dB
• Componentry
  • 11 IC, 1 opto-coupler, 4 triac, 60 transistors, 33 diodes, 5 LED, 2 bridge rectifier, 3 relay
• Power supply
  • 100-240 V ~ ±10 % switchable: 100 V, 120 V, 140 V, 200 V, 220 V, 240 V. Mains frequencies 50 to 60 Hz without switching. Power consumption 80 watts
  • Mains fuses: 100 to 140 V: 1 AT, 200 to 240 V: 0.5 AT ***For 230 V mains***Voltage selector switch always on 240 V***.

Special Equipment

Remarks

• Other models of the same series:
• Revox A 77, predecessor.
• Revox A 700
• Revox B 77
• Revox PR 99

Pictures

• Image: Revox B 77

• Picture: Revox B 77

• Picture: Revox B 77

• Picture: Revox B 77

• Picture: Revox B 77

• Picture: Revox B 77

• Picture: Revox B 77

• Picture: Revox B 77

Test reports

• Revox B77 Dolby compared to ASC 6002, HiFi-Stereophonie 1979-05 (Arndt Klingelnberg)

• Report in "FonoForum" 9 / 1978

Links

• Revox A77 user manual, Revox B77 service manual
• tape machines on Revox website, July 2015