User manual STUDER REVOX B77 SERVICE MANUAL

[. . . ] 25 years ago, each recording studio contained two or three of them; to make copies or to generate echoes or to delay the signal sent to the reverberations with plate or springs. [. . . ] Several accessories appeared progressively: plates and cores CCIR or NAB and a kit to use loops of magnetic tape It left then a model 38 and 19 cm/s CCIR, generalized in the studios and, of course, most interesting, there is a model with 4 tracks stereo (1/4 of track) and a model Dolby B; to avoid both!For our use, model 19-38 is the only interesting one. Lastly, do not miss the end of this page: if you are owner of an A77, you will find there, in pdf format, all the electronic diagrams necessary to its repair. DESIGN FEATURES General principle: Tape speeds: mechanism with 3 motors, all electronically controlled 19 cm/s (7 1/2 in/s) 9, 5 cm/s (3 3/4 in/s) « ± 0, 08 % @ 19 cm/s « ± 0, 1 % @ 9, 5 cm/s <= 0, 2% maximum 26, 5 cm ( 10 1/2 in ) Horizontal or vertical equipped entirely with transistors with silicon structure double diffusion 30 Hz @ 20 kHz +2/-3 dB 50 Hz @ 15 kHz ± 1 , 5 dB 30 Hz @ 16 kHz +2/-3 dB 50 Hz @ 10 kHz ± 1, 5 dB à 19 cm/s à 9, 5 cm/s ±0, 2 % Wow and Flutter: Drift: Diameter of the reels: Position of operation: Amplifiers: Response curve recording-reading: Harmonic distortion: (maximum level @ 1 kHz) Corrections: Signal ratio/noise: (balanced with filter DC IF) Retreat of cross talk (@ 1 kHz): <= 2 % @ 19 cm/s <= 3 % @ 9, 5 cm/s recording NAB, commutable reading NAB or IEC >= 58 dB @ 19 cm/s >= 56 dB @ 9, 5 cm/s >= 60 dB, mono >= 45 dB, stereo 120 kHz, push-pull oscillator Oscillation frequency: Inputs per channel: cinch and jack DIN 5 poles cinch Outputs per channel: DIN 5 poles cinch jack Microphones commutable LO/HI LOW: 50 @ 600 ohms 0, 15 mV HIGH: 100 kohms 2, 5 mV RADIO: 33 kohms 2, 5 mV AUX: 1 Mohms 35 mV OUTPUT max. [. . . ] DESIGN FEATURES General principle: Tape speeds: mechanism with 3 motors, all electronically controlled 19 cm/s (7 1/2 in/s) 9, 5 cm/s (3 3/4 in/s) « ± 0, 08 % @ 19 cm/s « ± 0, 1 % @ 9, 5 cm/s <= 0, 2% maximum 26, 5 cm ( 10 1/2 in ) Horizontal or vertical equipped entirely with transistors with silicon structure double diffusion 30 Hz @ 20 kHz +2/-3 dB 50 Hz @ 15 kHz ± 1 , 5 dB 30 Hz @ 16 kHz +2/-3 dB 50 Hz @ 10 kHz ± 1, 5 dB à 19 cm/s à 9, 5 cm/s ±0, 2 % Wow and Flutter: Drift: Diameter of the reels: Position of operation: Amplifiers: Response curve recording-reading: Harmonic distortion: (maximum level @ 1 kHz) Corrections: Signal ratio/noise: (balanced with filter DC IF) Retreat of cross talk (@ 1 kHz): <= 2 % @ 19 cm/s <= 3 % @ 9, 5 cm/s recording NAB, commutable reading NAB or IEC >= 58 dB @ 19 cm/s >= 56 dB @ 9, 5 cm/s >= 60 dB, mono >= 45 dB, stereo 120 kHz, push-pull oscillator Oscillation frequency: Inputs per channel: cinch and jack DIN 5 poles cinch Outputs per channel: DIN 5 poles cinch jack Microphones commutable LO/HI LOW: 50 @ 600 ohms 0, 15 mV HIGH: 100 kohms 2, 5 mV RADIO: 33 kohms 2, 5 mV AUX: 1 Mohms 35 mV OUTPUT max. [. . . ]