Revox C115 cassette tape deck

Cassette Tape Deck - Professional Series

System

Tape transport

Dual capstan transport, 3-head system

Auto tape type

Automatic setting for IEC type I, II, IV

HX-Pro

Permanently active headroom extension to increase the overall dynamic range

 

Ease of use - minimum of training and familiarization required

Balanced arrangement of operating and control elements

Large display with high contrast lettering

Feedback for each key depression on the high contrast display and LED's

Fader start mode interlocks the keyboard

Ergonomic design - characterized by the attractive, classic and discreet design, even professionals under stress will feel comfortable with the Revox C115 Cassette Tape Deck

Large and clearly separated controls for all functions

Functional clarity minimizes operating errors

The power switch, often dreaded by professionals, has been arranged on the rear panel

Useful features and optionas - help to customize the unit and supply the professinal with a reliable tool

Different studio levels externally switchable

De-energized capstan motor in standby

Bias and calibration easily adjustable on front panel

Standardized interfaces for audio and fader control

Simple and quick access to moduls minimizes service time

Rackmount kit optional

 

Specifications

Transport:  Dual capstan tape transport with controlled spooling drive. Separate head system for record and playback; ferrite erase head

Tape Speed:  1-7/8 ips ±0,5%

Tape Slip:  <0,3%

Wow and Flutter (weight as per JIS):  <0,1% (C-60 and C-90 in playback mode)

Spooling Time:  approx. 95 sec for C-60 cassette

Tape Timer:  switchable between, min/sec , linear counter, 4 digits

Automatic Tape Type Changover:  for typ[es I, II and IV

Recording System:  HX-Pro Headroom Extension

Calibration Aid:  Rotary controls for Bias and Level via bargraph display

Noise Reduction System:  Dolby B and C type, Double Dolby System for source/tape monitoring

Reproduce Equalization:

Type I :  3180 +120 µs

Type II :  3180 + 70 µs

Type IV :  3180 + 70 µs

Frequency Response (via Tape, -20 dB Dolby NR =Off)

Type I :  30 Hz - 18 kHz ±3 dB

Type II :  30 Hz - 17 kHz ±3 dB

Type IV :  30 Hz - 17 kHz ±3 dB

Level Calibration:  200 nWb/m =0 dB = Dolby-level

Harmonic Distortion (k3 of 333 Hz at 200 nWb/m)

Type I :  <1,0%

Type II :  <1,5%

Type IV :  <1,5%

Signal-to-Noise Ratio (ref.to 3% distortion and Dolby C)

Type I :  >72 dB

Type II :  >72 dB

Type IV :  >73 dB

Channel Separation:  better than -40 dB at 1 kHz

Bias/Erase Frequency:  105 kHz

Erase Efficiency:  >65 dB at 1 kHz (Dolby C =on)

Input Sensitivity/Impedance:  70 mV for 200 nWb/m / >10 k Ω

Max. Input Level:  10 V

Outputs (rel. To 200 nWb/m)

Line Out :  -10/0/+6 dBm, R=50 Ω

Phones :  max. 500 mV, R=100 Ω

4special Function:  Faderstart, to be activated via 6-pole socket (DIN 45 322)

Power Requirements:  115 V, 90 - 130 V, (230 V, 190 - 260 V) 50/60 Hz

Power Consumption:  30 W

Dimensions (W x H x D):  440 x 143 x 366 mm

Weigth:  7,5 kg

Revox B 791 turntable

 

With the B791 (and B795) turntables, tangential tracking has been brought to the point of perfection. While conventional reproduction systems offer good compromises, Revox solves some problems that were once thought unsolvable. Disadvantages resulting from the opposing physical forces inherent in disc reproduction have been overcome by significant engineering breakthroughs. New solutions have made Revox the leader in turntable technology.

Pivoting Tonearm Module

The revox concept of a pivoting tonearm module, together with the ultra-short tangential tonearm, represents a successful synthesis of technical innovation and mechanical perfection. In this exclusive design the usual resonance problems of tubular tonearms have been eliminated and the threat of damage to either disc or cartridge stylus has become a thing of the past.

An electronic servo control keeps the stylus tracking precisely in the center of the record groove, thus avoiding playback distortions. Record warps and eccentricities are no problem. The result is a light, delicate tracking of your valuable discs from the first groove to the last.

 

Quartz-Crystal for Constant Speed

Developed and manufactured by Revox, the B791 (and B795) motor is Quartz controlled and drives the plater directly. Therefore,, use of a constant dust-removing device will not alter the locked-in speed. On the B791 the speed can be changed from -9,9% to +9,9% in precise o,1% steps, with a digital display showing the Variation. This allows the audiophile to obtain unlimited nuances for special effects, and also facilitates quick tuning of a record to a musical instrument.

 

Changing Cartridges

With Revox turntables you are not limited to the use of one cartridge. Four premium cartridges are available, factory installed and optimally adjusted. Of course you can also install practically any other cartridge that follows the international mounting norms.

 

Advanced Technology, Simple Operation

Ease of operation is practically a revox trademark, and here it begins with automatic cleaning of the stylus tip. A built-in light aids in finding specifica musical selections. All functions are activated by front panel buttons which may be operated even with the dust cover closed. With the development of the B791 (and B795), revox is once again leading the way. Precision, advanced technology, long-term reliability, and intelligent design are hallmarks of superiority.

 

Automatic Functions:

When swinging in the tone arm support - Platter starts to rotate at preselected speed

When swinging out the tone arm support - Cartridge lifts off immediately; Cartridge returns to start position; Platter stops, stylus illumination switches off

Operating

Platter Drive :  Power Switch; Two tactile feedback keys for selection speeds

Carriage:  Three tactile feedback keys for fast inward and outward movement as well as lifting and lowering the cartridge; built-in cartridge illumination

Speed:  Two tactile feedback keys for increasing or decreasing the platter speed.

Display:  5-Digit display for nominal speed and deviation in percent

Specifications:

Platter Drive:  Quartz- controlled direct drive system

Platter Speeds:  33 and 45 RPM

Speed Adjust. Range:  ±09,9%, quartz accurate

Speed Stability:  ±0,01%

Speed Indications:  Speed and synchro indicator (33 and 45 RPM)

Platter:

Diameter :  313 mm (12,32")

Weight :  2,1 kg (4 lbs 10 oz)

Acceleration Time:  less than 2 sec. to 33 RPM

Deceleration Time:  less than 2 sec. from 45 to 33 RPM

Wow and Flutter:

Weighted :  better than 0,05%

Linear :  better than 0,1%

Rumble (Unweighted):  better than -50 dB (DIN 45539A)

Rumble (Unweigted with 20 Hz high-pass:  better than -52 dB (DIN 45539A)

Rumble (Weighted):  better than -72 dB (DIN 45539B)

Tone-arm:

Linear-tracking tone arm with servoelectronic follow-up control

Tangential Tracking Error:  smaller than 0,5°

Skating Compensation:  Not required with a tangentially tracking system

Stylus Force:  Adjustable with balance weight from 8 to 20 mN (0,8 to 2 p)

Tone-arm Lowering:  Electronically controlled, pneumatically damped

Muting:  Electronic muting until stylus contacts record (approx. 1 s)

Tone-arm Follow-up:  Optoelectronic sensing with LED as light source; servoelectronics an DC motor

Run-out Switch:  Automatically activated by servoelectronics

General

Semiconductors Components:  31 ICs, 46 Transistors; 45 Diodes; 4 LEDs; 2 Bridge rectifiers; 5 seven-segment displays

Power Requirements:  100/110/120 V 200/220/240 V ; 50/60 Hz

Power Consumption:  30 W max

Power Fuse

0,4 A (slow-blow) :  100 - 120 V

0,2 A (slow-blow) :  200 - 240 V

Dimensions (W x H x D):  449 x 142 x 395 mm (17,7" x 5,5" x 15,6")

Weight:  9,1 kg (20 lbs)

Revox B 795 turntable

 

Automatic Functions:

When swinging in the tone arm support - Platter starts to rotate at preselected speed

When swinging out the tone arm support - Cartridge lifts off immediately; Cartridge returns to start position; Platter stops, stylus illumination switches off

Operating

Platter Drive :  Power Switch; Two tactile feedback keys for selection speeds

Carriage:  Three tactile feedback keys for fast inward and outward movement as well as lifting and lowering the cartridge; built-in cartridge illumination

Specifications:

Platter Drive:  Quartz- controlled direct drive system

Platter Speeds:  33 and 45 RPM

Speed Stability:  ±0,01%

Speed Indications:  Speed and synchro indicator (33 and 45 RPM)

Platter:

Diameter :  313 mm (12,32")

Weight :  2,1 kg (4 lbs 10 oz)

Acceleration Time:  less than 2 sec. to 33 RPM

Deceleration Time:  less than 2 sec. from 45 to 33 RPM

Wow and Flutter:

Weighted :  better than 0,05%

Linear :  better than 0,1%

Rumble (Unweighted):  better than -48 dB (DIN 45539A)

Rumble (Unweigted with 20 Hz high-pass):  better than -50 dB (DIN 45539A)

Rumble (Weighted):  better than -70 dB (DIN 45539B)

Tone-arm:

Linear-tracking tone arm with servoelectronic follow-up control

Tangential Tracking Error:  smaller than 0,5°

Skating Compensation:  Not required with a tangentially tracking system

Stylus Force:  Adjustable with balance weight from 8 to 20 mN (0,8 to 2 p)

Tone-arm Lowering:  Elecrtonically controlled, pneumatically damped

Muting:  Electronic muting until stylus contacts record

Tone-arm Follow-up:  Optoelectronic sensing with LED as light source; servoelectronics an DC motor

Run-out Switch:  Automatically activated by servoelectronics

General

Semiconductors Components:  21 ICs, 19 Transistors; 29 Diodes; 4 LEDs; 2 Bridge rectifiers

Power Requirements:  100/110/120 V 200/220/240 V ; 50/60 Hz

Power Consumption:  30 W max

Power Fuse

0,4 A (slow-blow) :  100 - 120 V

0,2 A (slow-blow) :  200 - 240 V

Dimensions (W x H x D):  449 x 142 x 395 mm (17,7" x 5,5" x 15,6")

Weight:  9,1 kg (20 lbs)

Revox B780 receiver

In its B780 receiver Revox has achieved a truly symbiotic relationship between tuner and amplifier. Each retains its identity; the circuitry and performance of both the B760 Digital Frequency Syntesizer FM Tuner and the Revox B750 Integrated Amplifier are combined in the B780. instaed of trading flexibility for single-unit convenience, however, the capabilities of each unit have been enhanced by their merger into the Revox B780.

What makes the B780 more than the sum of its component parts is a microprocessor unit that takes over switching functions that would normally require an inordinate number of hard-wired connections and printed circuits. At the same time that it serves to increase the reliability of the B780, the microprocessor control system makes the receiver even easier to use.

As the nerve center for your entire component high-fidelity system, the Revox B780 provides connection and control facilities for two loudspeaker systems and for fourstereo sources in addition to its built-in FM tuner; a phono cartridge, two tape recorders, and an auxiliary source, such as a Tv set, AM tuner, or the like. Each input is fully buffered, and so, can be used independently. That is to say, if you wish, you can record an FM broadcast on your open real deck at the same time as you are listening to the playback of an LP. in place of the usual rotary "Selector Switch", your choice of input signals is electronically routed through the amplifier via individual pushbuttons ( with lighted indicators) that command the microprocessor to switch to the appropriate source. Even when the B780 is turned off, the microprocessor retains the last-selected program source in its memory, so when you turn the unit on again. It "wakes up" properly switched to that input.

Lighted digits show which program source is going to the recorder circuits. These pushbutton choices are also retained in the microprocessor memory, giving you the convenience of mechanical switching with vastly improved reliability.

The same principle of all pushbutton operation is applied throughout the tuner section of the B780. there is no conventional FM dial for the selected station frequency, as it is indicated ( to two decimal places ) on a digital red-out. There is no conventional FM dial for selected station frequency, as it is indicated on a digital read-out. There is no conventional tuning knob, with its dial cord and pulleys; rather; pushbuttons cause the tuner to scan upward or down-ward in frequency in 50 kHz incrementes, stopping at each receivable station, or at each stereo station, or switching into mono when the station's signal strength is not adequate for proper stereo reception.

Because of its quartz-crystal controlled frequency synthesizer, tuning is always exact; only by using a laboratory FM generator and distortion analyzer could such precision be obtained with normal manual tuning. And the pushbutton memory system of the B780 allows you to store the frequencies of up to 18 favorite stations for instant recall.

Long awaited, the Revox B780 receiver embodies the most up-to-date technology, in its most convenient form, in the service of the one goal that inspire all Studer Revox products; to bring you the most faithful possible reproduction of musical sound.

 Specifications:

Tuner Section

Tuning Range:  87,50 - 107,975 MHz

Tuning Accuracy:  ±0,0025%

IHF (30-dB) Monophonic Usable Sensitivity:  19,µV / 300 Ω (10,8 dBf)

IHF (IHF-T-200) Monophonic 50 dB Quieting Sensitivity:  2,5 µV / 300 Ω (13,2 dBf)

IHF (IHF-T-200) Stereophonic 50 dB Quieting Sensitivity:  30 µV / 300 Ω (34,8 dBf)

Image Rejection:  106 dB

IF Rejection:  110 dB

Spurious Response Ratio:  106 dB

Capture Ratio (at 65 dBf):  2 dB

Selectivity Adjacent Channel:  16 dB

Selectivity Alternate Channel:  78 dB

 AM Suppression:  70 dB

Subcarrier Product Rejection:  72 dB

Frequency Response:  30 Hz - 15 kHz ±1 dB

Deemphasis:  50 or 75 µs (switchable) with built-in Noise Reduction Unit 25 µs

Total Harmonic Distortion(at 65 dBf):

At 100 Hz :  0,15% (mono);  0,35% (stereo0

At 1 kHz :  0,1 (mono);  0,25% (stereo)

At 6 kHz :  0,2% (mono);  0,2% 9stereo0

Stereo Separation [Mono]:

At 100 Hz :  40 dB

At 1 kHz :  42 dB

At 10 kHz :  33 dB

Signal-to-Noise ratio 9at 65 dBf):

Mono :  78 dB

Stereo :  74 dB

Muting Thresholds:

Mono :  17,3 - 37,3 dBf

Stereo :  25,2 - 65,2 dBf

Antenna Inputs:

60 -75 Ω coaxial

240 - 300 Ω balanced

Audio Outputs:

75 kHz deviation/400 Hz equals 0,7 volt at the output Tape 1

15 kHz deviation/400 Hz produces 70 watts/ 8 Ω at the output Speakers A/B

Oscilloscope Output:

Vertical :  50 mV /75 Ω, RF =1 Volt

Horizontal :  75 kHz deviation = 2,8 Volt pp

Amplifier Section

Power Output:  70 watts/channel min. RMS into 8 Ω from 20 Hz - 20 kHz with no more than 0,05% T.H.D.

Total Harmonic Distortion:   0,03% at rated output

IHF Intermodulation Distortion (14 kHz/15 kHz):  less than 0,03% at rated output

TIM Distortion (Otala, lowpass 10 kHz):  less than 0,08% at rated output

Dynamic Headroom:  1 dB

Slew rate:

15 V/µs ( limited by internal low pass filter)

30 V/µs (without low pass filter0

Frequency Response:  20 Hz - 20 kHz +0 dB/-0,7 dB

Damping Factor:  better than 100 at 8 Ω and 1 kHz

Inputs Sensitivity (for 70 watts [8 Ω])/Impedance

Aux, Tape 1, 2 :  150 mV/50 k Ω

Phono :  3 mV/47 k Ω, 220 pF

PWR In :  1 V/50 k Ω

Input Overload Margin (phono, Aux, Tape 1, 2):  better than 30 dB

Outputs;

DIN Connector Tape 2/Out:  5,5 mV/R 10 Ω

Speakers A, B :  23,7 V (8 Ω)

Tape 1 :  135 mV/R min. 47 k Ω

Pre Out (DIN connector) ;  0,85 V/R min. 10 k Ω

Pre Amp Out (jack) :  0,85 V/R min. 47 k Ω

Phones :  11,8 V/R 220 Ω

Signal-to-Noise Ratio (RMS value, unweighted 20 Hz - 20 kHz relative to 70 W/8 Ω)

Aux, Tape 1, 2 :  better than 90 dB

Phono 1 + 2 9ref. 5 mV, A-weighted):  better than 82 dB

Crosstalk (at 1 kHz):  better than 70 dB

Phono Equalization:  20 Hz - 20 kHz ±0,5 dB (in accordance with IEC 98, MOD 4 1976, consistent with RIAA)

Tone Controls:

Bass  :  ±8 dB at 120 Hz

Treble :  ±8 dB at 8 kHz

Presence ;   ±8 dB at 3 kHz

Filters:

Low :  50 Hz, -3 dB (12 dB/oct)

High :  8 kh, -3 dB (12 dB/oct)

Loudness (Vol-40 dB):  100 Hz +5 dB , 10 kHz +6 dB

General Section

Semiconductors:  122 Transistors;  99 Diodes;  19 variable capacity Double Diodes:  46 ICs:  1 micro-processor; 4 K x 8 Bit, 5 Bridge Rectifiers, 9 7-Segment Displays

Electric Current Supply:  100, 120, 140, 200, 220, 240 V AC ±10% (voltage selector) 50/60 Hz

Power Consumption:  550 W max.

Dimensions (W x H x D):  452 x 151 x 420 mm (17,8" x 6" x 16,5 ")

Weight:  17 kg (37 lbs)

Revox A 50

Revox A50 Stereo Amplifier

The A50 amplifier is a unit of central importance within a hifi music system. Its power handling capacity is a decisive factor for high quality sound reproduction from tape, disc or off the air. For this reason, extremely careful attention has been given to every design detail of the Revox A50  Stereo Power Amnplifier, whose sine wave rms rating of 2x40 watts will satisfy the most discriminating demands. Silicon transistors are used throughout its circuitry, which is made up of pluggable PC-boards. From the softest sounds up to the rated output power, distortion remains negligible. pre-set level controls eliminate any volume changes when switching between different signal sources. A separate button provides for off tape monbitoring through the power amplifier. Step-type bass and treble controls permit exactly reproducible settings for each channel, as well as a defined Linear response. headphone outputs and switchable filters round up the many distinctive features of the outstanding revox A50 Stero  Power Amplifier.

Specifications:

Continuous Sine Wave Output:  2 x 40 W at 4-8 Ω  ( 2 x 25 W at 16 Ω )

Music Power:  2 x 70 W at 4-8 Ω  (2 x 40 W at 16 Ω )

Distortion:  less than 0,1% at 1 kHz (less than 0,3% from 40 Hz to 15 kHz)

Intermodulation:  less than 0,3%

Frequency Response:  20 Hz - 20 kHz ±1dB

Powertbandwidth:  10 Hz - 40 kHz

Inputs Sensitivity/Impedance:

Micro :  3 mV/100 k Ω

Phono Magnetic :  3 mV (2 - 7 mV) / 47 k Ω

Tape, Tuner :  100 mV (better than 90 mV)/ 100 k Ω

Auxiliary :  100 mV (better than 90 mV)/ 330 k Ω

Phono Ceramic :  230 mV (better than 180 mV)/ 800 k Ω

Tape Monitor :  250 mV (better than 180 mV)/ 50 k Ω

Signal-to-Noise Ratio (unweighted),

At nominal sensitivity reffered to 40 W, 8 Ω load

Phono :  better than 65 dB

Tape, Tuner, Aux :  better than 75 dB

Tape Monitor :  better than 80 dB

At nominal sensitivity reffered to 50 mW, 8 ohm load

Phono :  better than 50 dB

Tape, Tuner, Aux :  better than 50 dB

Tape Monitor :  better than 50 dB

Intrchannel Crosstalk:  better than 60 dB (1 kHz)

Damping Factor:  better than 20

Tone Control (4 dB steps):  ±12 dB at 60 Hz; ±12 dB at 12 kHz

Low Filter :  -8 dB at 60 Hz (12 dB/oct)

High Filter :  -15 dB at 12 kHz (12 dB/oct)

Loudness Control:  60 Hz : -5 dB/1 kHz: -16 dB / 12 kHz : -12 dB

Phono Equalization (RIAA):  ±1 db / 50 Hz ... 15 kHz

Power Supply:  110,130, 150, 220, 240, 250 V 50/60 Hz

Semiconductor Component:  30 Silicon Transistors;  3 Silicon Rectifiers;  14 Diodes

Dimensions (W x H x D):  415 x 160 x 245 mm

Weight:  8,2 kg (18 lbs)

Revox A 76

A76 Revox Builds the tuner of the future.

The conventional design concepts for tuners are not satisfactory any more if one wants to reach the optimum in freedom from distortion and signal interference. Therefore, Revox have tossed overboard traditional ideas and by designing the "third generation tuner" they have  a whole leap forward.

The approach  has been thoroughly professional and without compromise. The input section features "dual gate" field effect transistors and quadruple variable capacitor tuning, while the IF-strip consists of a passive Gauss Filter, followed by an amplifier which is made up entirely of integrated Circuits (bandwidth 5 MHz). delay-lines are employed for demodulation without deteriorating the five megahertz bandwidth. A76 khz oscillator runs phase-locked to the subcarrier and supplies  after binary scaling the switching frequency to the stereo demodulator. Supplementary circuits permit silent tuning and effect automatic stereo changeover, they triogger a visual signal in th ecase of multipath reception and provide for th eindication of signal strength, centre tuning and the presence of a Stereo modulated carrier. To describe the distortion and noise free performance of  this tuner is virtually impossible.

Special Features:

Antenna Inputs:  60 ohms unbalanced (BNC); 240 ohms balanced (DIN)

RF-Input circuit with 2 MOS-FET and 4-section variable air - capacitor

Passiv gauss IF - Filter

Wideband IF - amplifier with 5 integrated circuits

Delay-line demodulator

Subcarrier regeneration with "phase locked loop" oscillator

Separate subcarrier demodulation with subsequent matrixing

Automatic stereo-mono selection

Silent tuning

Meters for Fieldstrength and Centre tuning indication

Stereo indicator light

Multipath warning light

Specifications

Tuning Range:  87,5 - 108 MHz

Sensitivity (60 Ω, 30 dB S/N, deviation 15 kHz):  1 µV

Static Selectivity 9at 300 kHz separation):  60 dB

Operational Selectivity (for two signals 100 µV and 1 mV, 40 kHz dev.at 1 kHz, 300 kHz separation):  80 dB

Spurious Response:  90 dB

Image Response:  70 dB

Bandwidth:

 IF Filter:  130 kHz

IF Ampl. And Demodulator :  5 MHz

Capture ratio:  1 dB

Pulse Noise Rejection (signal 100 µV and 1 mV peak per 100 kHz pulse noise, 75 kHz deviation):  40 dB

Distortion (40 kHz deviation at 1 kHz):  0,2%

Signal-to-Noise Ratio (unweighted, 75 kHz deviation):  70 dB

Stereo Separation:  40 dB 91 kHz)

Pilot Signal and Subcarrier Suppression: 40 dB

Audio Output (75 kHz deviation; adjustable, low internal impedance):  1 V

Frequency Response:  30 Hz - 15 kHz, -1 dB

Deemphasis:  50 µs

Semiconductor Complement:

Dual Insulated-gate FET :  2

Intergated Circuits :  6

Silicon Transistors :  41

Diodes :  27

Silicon Rectifiers :  2

Power Supply:  110, 130, 150, 220, 240, 250 V, 50/60 Hz

Power Consumption:  20 W

Dimensions (W x H x D):  415 x 160 x 245 mm

Weight:  7,8 kg (17,5 lbs)

Revox G 36

 Widely acclaimed throughout the world for its superb craftsmanship, the ReVox tape recorder is now available for the first time in U.S. and Canadian markets. The discriminating audiophile is well aware that there can be no compromise with quality and that the excellence of tape recordings is directly dependent on the skill and care used in the manufacture of their tape recorder. Quality control, constant checking and testing during every phase of ReVox manufacture and the use of highly rated components are the hallmarks of this superior instrument. ReVox is backed by a tradition of almost two decades in the manufacture of studio and broadcast tape equipment. The experience gained has resulted in ideas which have been incorporated into each ReVox. The ReVox, the instrument of choice by amateur and professional tape recordists, is also used in numerous industrial applications, in universities, as a teaching aid.. And as the focal point in home entertainment centers.  Its applications are seemingly limitless. Its quality is singular.

 Professional Features of the ReVox

Push-button electrical control of all operating modes.

Spool turnscounter.

Remote control facility.

Recorder can be used as an amplifier by switching off the capstan motor.

Additional low-impedence speakers can be connected.

Handy carrying case with pockets for two 10 ½" reels.

Constant speed hysteresis-synchronous heavy duty Pabst motor using direct drive of capstan. No belt of friction drives for the capstan shaft.

No pressure pads to clean - no pressure pads to wear out. This assures long head life and avoids longitudinal vibrations of the tape.

Three ring-core heads (2- or 4-track).

Separate pabst Outer-Rotor motors fro wind and rewind.

Tape speeds of 7½ and 3¾ i.p.s. obtainable through pole switching of capstan motor.

Reel size selector assures uniform tape tension for reels up to 10 ½ inches.

Recorder may be operated horizontally or vertically. Tape reels can be locked on to their shafts.

Two separate recording and replay amplifiers.

Cathode-follower low-impedance outputs.

Six-watt built-in monitor amplifier.

Two VU-meters with dynamic characteristics as per the ASA for individual record level control.

Both inputs may be mixed for mono-recordings.

Duoplay (sound with sound), Multiplay (sound on sound) and echo are possible wihout accessories.

Special Design of The ReVox

Three PABST Outer-Rotor Motors

Three motors are usually found only in professional tape recorders. This rather costly design assures optimum performance especially regarding to wow and flutter, and it is mechanically simple without containing any fast wearing parts.

 A design unique for an amateur recorder. Consisting of five diecastings, these parts, when attached to one another, from the very rigid unit which carries  the head-block and tape-guides. This assures perfect and permanent head alignment under the roughest operating conditions. The powerful Hysteresis-Synchronous-Motor and the heavy accurately balanced flywheel are mounted in a diecast cage. The runout of the capstan shaft must not exceed 0,001 mm in order to pass inspection. This is a degree of accuracy found only in studio an broadcast equipments.

 6/12 Hysteresis-Synchronous  Motor

The heavy-duty direct drive capstan motor is a hysteresis synchronous unit. The speed is electrically changed by controlling the number of poles. Maximum playing time can be had by setting the tape speed at 33 ¾ ips or superior quality by using a tape speed of 7 ½ ips.

Anti-Wow ans Anti-Flutter Design

The speed of the heavy-duty Pabst motor for the capstan is locked in with the power-line frequency, assuring remarkable uniformity of capstan shaft speed rotation. The motor is completely shielded, eliminating any stray megnetic motor flux. Precision bearings on the drive shaft removes the lateral pressure caused by the pinch roller and protect the motor from any uneven load.

Tape reels Up to 10 ½" Diameter

Maximum recording or playback time is assured through the use of reels having a diameter of 10½". These reels will accommodate up to 4800 feet of Lptape. Rewind can be accomplished in a few moments. Tape tension is controlled with a simple, easily operated, readily accessible control, which is designed so that large reels cannot be placed into position when it is set for reduced tape tension.

Separate VU-meters for each channel

The VU-meters on the ReVox are precision instruments with dynamic characteristics as required by the A.S.A. in the standard for volume measurement of complex waves. Accurate control of recording level is possible. Scale illumination of these meters is switched with the channel selector for added operating convenience.

 Solenoid Operated, Oversized Brakes

The brake bands are lifted off the linings during any operating mode. The required tape tension is achieved electrically by counter-torque on the winding motors. This assures minimum wear of mechanical parts. Braking is quick and positive from fast wind, even in the event of power failure.

Mechanical tape Stop

Because of the very fast winding speeds used by the ReVox, the instrument does not depend on metal contacts for stopping the recorder. A microswitch senses the end of the tape and turns off the motor circuits automatically after a real has been rewound. Automatic motor shutoff also takes place when a tape splice has opened.

Bulit-in Mixing Facilities

The mixing arrangements provide for the one pre-amplifier not in use for recording to be coupled with the other pre-amplifier through which the recording is being made, with neither gain control acting as a master. Thus any two signals may be mixed and recorded in the mono mode. The same controls are used for adjusting level and balence when recording stereophonically. Additionally, one channel can be set to playback while the other recording and all forms of sound-on-sound and sound-with-sound are possible.

Separate record and Playback - Amplifiers for both channels

The record amplifier hs a reserve gain of 14 dB before any distortion. Through the used of separate heads for record and play, continuous monitoring becomes possible.

Hum level

Every effort has been made to keep hum at an absolutely minimum level. The first stages of the amplifier have D.C. heated filaments. Teh power transformer has a grain oriented strip-wound core providing a minimum of stray magnetic field, reducing hum pickup.

 With the use of three motors the ultimate in simplicity can be achieved. Two motors for winding and rewinding and a third, the Capstan motor, for smooth and even tape transport during recording and replaying. There are no belts - other than that for the counter - no levers and no gears required for engaging the various operating modes

A glance at the amplifier chassis revoalscomponents of the highest quality not gonerally found in home equipment. Simple and easy to follow wiring takes the problems out of servicing.

Tubes

In addition to three silicon diodes and three selenium rectifiers, the ReVox uses a total of twelve dual function tubes. Each stage has been designed for single function operation. No simplification, with attendent tachnical compromise, has been permitted.

Oscillator Bias

A 70 kc push-pull oscillator is uded for highest erase efficiency, optimum signal-to-noise ratio and low signal distortion.

Specifications

Tape Speeds:  7½ and 3¾ i.p.s.

Speed Accuracy:  ±0,3%

Wow and Flutter:  max. ±0,1% at 7½ i.p.s.

Tape Speed Deviation:  0,3%, or less, from nominal

Frequency Response:

40 to 18,000 Hz at 7½ i.p.s.

40 to 12,000 Hz at 3¾ i.p.s.

Equalization:  NAB standards

Replay S/N Ratio:  better than 50 dB (referred to peak level)

Overall S/N Weighted:  55 dB at 7½ i.p.s. (for half-track operation)

Cross-Talk Rejection [Mono / Stereo]:  55 dB / 45 dB

Bias oscillator:  70 kc push-pull

Inputs per Channel:

Microphone : 3 mV at 1 megohm input impedance, 600 mV maximum 

Tuner : 50 mV at 1 megohm, 10 V maximum

Aux : 50 mV at 47,000 ohms (diode)

Outputs:

Two cathode-follower outputs

2-track  : 0,7 V

4-track  : 0,5V

Impedance:  5,000 and 100,000 ohms

Tubes and Semiconductors:

5 x ECC81;  1 X ECC82;  4 X ECC83;  2 X ECL86;

3 Silicon Diodes;  3 Selenium Rectifiers

Line Voltage:  117 V 60 Hz ( USA and Canada)

Power Consumption:  120 watts

Case Dimensions:  18½ x 12¼ x 11½ inches

Weight:  45 lbs approx.

Color:  Gray and aluminum frame with blue-gray plastic

Revox B 790

Will Studer developed the revolutionary Revox b790 true tangential tracking turntable. It replaces the conventional tonearm and all its problems with a unique, patented opto-electronic playback servo-system. The cartridge moves up, down and laterally guided by a beam of light. It's easy on your record grooves and easy on your nerves. It's so simple and goof-proof even a child can safely play your most treasured records.

The new revox B790 looks and performs better than any turntable you've ever seen or heard. ...

The Revox B790 record player with quartz-controlled direct drive and tangential pick-up arm was not just exciting because of its advanced design but because of a complete range of functional innovations. The B790 united security and simplicity of operation and essentially offered new solutions to old problems.

The B790 features adjustable speed over a '7% range and a four-digit LED indicator which displays the measured rate of rotation, but otherwise the two models are the same. The tonearm design provides straight line (tangential) tracking which maintains a constant lateral tracking angle and thereby reduces certain forms of playback distortion, since record masters are always cut with tangential heads. Distortion due to skating is said to be eliminated by this design as well. Another goal of the Revox design was for the moving system to have very low effective mass. This was achieved by hanging the cartridge from a horizontal rail system. The "arm" on which the cartridge is mounted is just four centimeters long and its dynamic mass is claimed to be only 3.75 grams.

The Revox system is sold at present with either an Ortofon or an AKG cartridge. Users can buy a kit which facilitates the installation of other cartridges. Tests by Revox have shown that the fundamental resonance of this arm with most cartridges lies between 10 and 11 hertz where it would not readily be stimulated either by record warps or recorded audio signals.

The arm and cartridge are guided along the rail system by a small motorized carriage. A block assembly which contains these rails and the carriage, arm, and cartridge is then pivoted in much the same way as a conventional tonearm. To put on or to remove a record, one sets the block assembly into its "at rest" position out of the way of the platter. And to play a record, one sets the assembly over the record's surface into a detent with a claimed repeatability of ± 0. 01 mm! This starts the turntable motor, but the stylus stays lifted above the record's edge until the user presses a button to lower it. While it is lifted, cuing can be accomplished with two other push buttons.

As a record is played, the carriage is propelled forward in response to signals from an ingenious optical and electronic system. Time constants of the system are chosen so that the arm moves smoothly, and so that an eccentric groove is tracked about in the center of its range of excursion. (The back-motion is absorbed by the free-swinging arm, not the servo. )

The little tonearm has only one point of contact with the motorized carriage, a jeweled bearing which forms the lower pivot point. The vertical shaft of the tonearm is held captive by the field of a small, oblong, concave, permanent magnet. This magnet keeps the arm from rocking laterally, yet adds no friction to the system.

The mechanical suspension for the overall turntable system has its basic resonance at or below 3 Hz, rendering it quite insensitive to feedback even if it is set directly atop a subwoofer cabinet. This was demonstrated.

The dustcover, which is transparent and removable, is contoured such that it can be opened or closed even when the turntable is placed flush against a wall, and is sprung to "stay put" in any position. All operating controls are outside the locus of the dustcover.

Specifications

Turntable drive: Quartz-controlled direct drive

Speeds: 33,33 and 45 rpm, crystal accurate

Speed accuracy: ±0,01 %

Speed indication: 4-digit LED readout, quartz precise

Manual fine adjustment: ±7%

Platter diameter: 313 mm (12,32 inch)

Platter weight: 1,1 kg (2 lbs 7 ozs)

Run-up time: better than 2 sec. at 45 rpm

Braking time: better than 1,5 sec. from 45 to 33,33 rpm

Wow and Flutter: better than 0.05 % (weighted); 0,1% (unweighted)

Signal-to-noise ratio: better than 65 dB

Rumble to signal ratio:

A weighting: better than 48 dB

A weighting +20 Hz high-pass: better than 51 dB

Bweighting: better than 68 dB

Transmission characteristic for rumble measurement: Replay response -3 dB at 20 Hz

Tonearm: Linear tracking tonearm with servo electronic follow-up control

Tangential tracking angle error: less than 0.5 degrees

Tracking force: adjustable of 5... 20 mN (0.5... 2 p)

Tonearm lowering: electronically controlled, pneumatically damped

Muting: electronically muted, until the stylus contacts the record

Tonearm follow-up: Opto-electronic sensing with LED as light source, servo-electronics and DC motor

Run-out switch: automatically activated via servo-electronics

Operating controls:

Turntable drive:

3 tactile feedback keys for 33,33 and 45 rpm as well as for variable speed operation

Tonearm:

3 tactile feedback keys for fast inward or outward movement plus lowering and lifting of the pick-up cartridge; cartridge illumination built-in

Automatic functions:

Swinging the tonearm support in: Platter stsrts to rotate at the selected speed

Swinging the tonearm support out:

Immediate lifting of the cartridge

Tonearm returns to start pposition (run-in groove of a 12 inch disk)

Electronic braking of the platter

Components: 29 ICs, 30 transistors, 24 diodes, 1 LED, 4 seven segment displays and 3 bridge rectifier

Power supply: 100/110/120/200/220/240 V, 50/60 Hz

Dimensions (W x H x D): 452 x 142 x 382 mm (17,8 x 5,6 x 15,03 inches)

Weight: 11 kg 924 lbs 4 ozs)