Revox B77
built from 1977 - 1989
The Revox B77 replaced the Revox A77 in 1977. With the release of the B77, Revox became the global standard for semi-professional tape machines. These machines are still in use today. Approximately 220,000 were produced. Compared to the A77, the B77 features improved tape drive control and improved winding characteristics. The B77 was available in the following versions:
MKI
1977 - 1980
The B77 was introduced at the IFA in Berlin in 1977 with the B760 tuner and the B750 amplifier. The machine quickly became the world standard for semi-professional tape machines and is still one of the most popular devices today.The high stability and quality of the B77 prompted Revox to upgrade the B77 to a PR99 and offer it as a PR99.
MKII
from 1980 and from serial number 100,000
The B77 MKII has a Variable Speed control located under the front panel. This allows the tape speed to be adjusted by +10% to -10%. There is no longer a Dolby version of this.
Technical data
| Drive: | Three-motor drive 2 AC winding motors 1 AC sound motor electronically controlled |
| Belt speed: | SLS 2.38 cm/s and 4.75 cm/s |
| LS 4.75 cm/s and 9.52 cm/s | |
| NS 9.52 cm/s and 19.05 cm/s | |
| HS 19.05 cm/s and 38.1 cm/s | |
| Pitch fluctuation: | 38 cm/s, 0.07 %, |
| 19 cm/s, 0.08 %, | |
| 9.5 cm/s, 0.10 % | |
| Coil size: | bis 26.5 cm ( 10.5 inch) |
| Rewind time: | 135 seconds for 1100 m tape |
| 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: | 67 dB (2-track), 63 dB (4-track) at 19 cm/s |
| 64 dB (2-track), 60 dB (4-track) at 9.5 cm/s | |
| Squeak: | max. 0,2 % |
| Equipment: | 11 ICs, 1 optocoupler, 4 triacs, 60 transistors, 33 diodes, 5 LEDs, 2 bridge rectifiers, 3 relays |
| Power consumption: | max. 80 VA |
Accessories for Revox B77
Pause function
Since 2004 we have been manufacturing the pause circuit for all Revox B77 (MK I and MK II) and PR99 (MK I to MK III).
more information
I was tired of having to hold down the pause button while the moderators were commenting!
Since 2014 we have been offering you the particularly convenient plug-in version.
Wired remote control
Every now and then we receive the cable remote controls for the Revox B77. They're really rare, and the cable remote controls are still in their original packaging, as shown in the photo.
If you're looking for a remote control, please feel free to contact us. Even though the cable remote control is very limited, we only sell our remote controls in serviced and tested condition!
Dust protection frame
We offer you new plexiglass backs for the dust covers of the Revox B77 in smoked glass look.
The back parts are glued and have 4 tabs that fit exactly between the upper front panel of the Revox B77 and the housing.
Cleaning kit B77
In our experience, most recording or playback problems are caused by dirty tape heads and tape guides.
Wow and flutter and poor winding are also part of the error pattern!
NAB-Adapter
Are your nab adapters worn and unsightly? Is the mechanism worn and jammed? Can you no longer lock the adapters? Are the spools no longer holding properly?
Then it's time for new nab adapters!
Precise mechanics, German manufacturing, new production
Spare parts for Revox B77
New drive control
Brand new and modern drive control for virtually all Studer Revox B77s. With electronic brake, version adjustable via DIP switch, galvanic isolation of the operating voltage and motor voltage, very low power consumption, and more.
more information
Quarz control
Quartz-accurate control of the tape speed, precise and fast regardless of temperature. Genuine plug and play, no soldering, no adjustment. Vari-Speed is retained if available. The synchronisation display can be led out.
Audio cards
We offer six new circuit boards for the audio section of the Revox B77. 22 years of Revox experience and nearly 50 years of experience with audio electronics have gone into these boards. The concept, implementation, layout, and production are all done in-house. This allows us to respond to customer requests particularly quickly and effectively.
We offer the following circuit boards:
Interconnection PCB 1.177.211
Input board 1.177.223
Record board 1,177,239
Oscillator board 1,177,235
Reproduce board 1.177.259
Monitor board 1.177.261
Pressure roller B77
A thing in itself!
Although pressure rollers made of polyurethane have been known for two decades for hardening, causing noises on the capstan, or for the PU to liquefy and run into the device, causing serious damage, pressure rollers of this type are still being sold!
It was a long road until we were able to offer you the rubber pressure rollers in the current quality!
We now only use sintered bronze bearings and genuine rubber. After production, all pressure rollers are round-ground. This is the only way we can maintain Revox's original specifications.
Counter B77
Since 2003 we have been manufacturing the digital counter for all Revox A77, Revox B77 and PR99 MK I. After developing a display for cable lengths using LED technology and a bit of boredom (those were the days), we came up with the idea of making a digital counter for Revox tape recorders.
The first counters were constructed exclusively with leaded components. The display height was 7.6 mm; smaller displays were not available. Only 7-segment displays using SMD technology were available with 5.1 mm digit heights. White 7-segment displays with 5.1 mm or 7.6 mm digit heights are manufactured specifically for us.
other Revox tape recorders
