The Revox B77
tape recorder
The Revox B77 Tape Deck
Proven Professional Design.
Precision Transport
Precision Three-Motors Drive
The capstan motor employs a precision-machined set of teeth at the circumference of its motor. As the motor turns, these teeth create a series of pulses that are read by a tachometer head and whose rate is compared against the frequency of a stable internal oscillator. In this way, even very slightest speed variations are immediately detected through a fast-acting servo system. To reduce wow and flutter even further, the direct-drive capstan shaft is machined to an accuracy of one one-thousandth of a millimeter, is hard chrome-plated and is artificially aged during the manufacturing process to ensure long-term stability
.Precision Heads and Electronics
The head nest of the B77 also contains space (1) for the inclusion of a fourth head, to be used for slide-projector synchronization or other audio-video control purposes, in addition to the regular erase, record play units. An infrared sensor within the head area (2) actuates automatic shut-off in the event of tape run-out or breakage.
Three-Head Monitoring and Special Effects
- Duoplay, where both recorded tracks are used simultaneously but for different, interspersed information, as in language laboratories.
- Simuplay, where a running commentary musical part, or translation is recorded on one track and a synchronized musical part or other accompanying material is recorded on the other.
- Sound-on-Sound, where a single individual, by playing various musical parts and successively mixing his live part with a previously recorded section, can build up an entire performance.
- Echo/Reverb, where tape-delayed echo or ambience can be added to a recorded track.
Precision Editing Facilities
Fine Speed Adjustment
Technical Data |
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Tape transport mechanism: |
3-motor tape drive, 2 AC driven spooling motors; 1 AC driven capstan motor, electronically regulated |
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Tape speeds: |
3.75 and 7.5 ips or 7.5 and 15 ips, electronic change-over |
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Tolerance from nominal: |
± 0.2%from: 2.5 ... 11 ips (3.75/7.5 ips machines) 5 ... 22 ips (7.5/15 ips machines) |
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Wow and flutter |
at 3.75 ips less than 0.1% |
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Tape slip: |
Max 0.2% |
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Reel size: |
Up to 10.5 inch diameter |
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Winding time: |
Approx. 135 sec for 3600 ft of tape |
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Tape transport control |
Integrated control logic with tape motion sensor provides for any desired transition between different operating modes. Contactless electronic switching all motors. Remote control of all functions and electronic timer operation are possible. |
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Equalization |
3.75 ips: 90 µsec / 3180 µsec |
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Frequency response |
At 3.75 ips: At 7.5 ips: At 15 ips: |
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Peak recording level: |
514 nWb/m corresponds to 6 dB above 0 VU |
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Level metering: |
VU meter as per ASA standard with LED peak level indicators |
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Distortion |
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At 0 VU |
At 0 VU + 6 dB |
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At 3.75 ips: |
< 1% |
< 2.5% |
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At 7.5 ips: |
< 0.6% |
< 1.5% |
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At 15 ips: |
< 0.6% |
> 1.5% |
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Signal to noise ratio |
Half track |
At 3.75 ips better than 64 dB |
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Quarter track |
At 3.75 ips better than 60 dB |
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Crosstalk |
Stereophonic |
Better than 45 dB |
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Erase depth: |
At 7.5 ips better than 75 dB |
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Inputs per channel |
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MIC (unbalanced) |
Position LO: |
0.15 mV / 2.2 kOhms |
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Position HI: |
2.8 mV / 110 kOhms |
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Radio: |
2.8 mV / 20 kOhms |
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AUX: |
40 mV / 220 kOhms |
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Overload margin on all inputs: |
40 dB (1:100) |
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Outputs per channel |
OUTPUT |
1.55 V, internal resistance 390 Ohms adjustable with preset control, max. attenuation -26 dB (Rj max. 1.5 kOhms) |
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RADIO: |
1.55 V, internal resistance 4.7 kOhms adjustable with preset control, max. attenuation -26 dB |
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PHONES: |
(2 x) max 5.6 V, internal resistance 220 Ohms, short-circuit proof, optimum matching impedance 200 ... 600 Ohms |
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Connectors for: |
Remote control of tape transport functions |
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Semi-conductor complement: |
11 IC, 1 opto-coupler, 4 Triac, 60 transistors, 33 diodes, 5 LED, 2 full wave rectifiers, 3 relays |
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Electric current supply |
100,120,140,200, 220,240 V |
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Main fuse: |
100 ... 140 V: 1 A slow-blowing |
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Weight: |
Approx. 37 lbs. 7 ozs (17 kg) |
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Dimensions (W x H x D): |
17.8 x 16.3 x 8.14 inches |
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Required clearance for 10.5 inch reels: |
Max width: 21.2 inches (538mm) |
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All figures quoted are minimum performance values normally exceeded by all units. Subject to change. |
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Revox B77 tape recorder equiped with:
dust cover, professional NAB hub adapters and aluminum reels
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