Revox B700 series
Studio technology for the living room.
The most important devices of the B700 series
Revox B710 (MK I and MK II)
Cassette tape recorder (1981 - 1984)
The world had to wait patiently for Studer Revox to develop a cassette recorder but once it was finally launched on the market, the Revox B710 very soon became the market leader.
At the core of the development was a 4 motor drive, that lived up to the high professional demands of the company. The drive worked without belt, friction clutches and mechanical brakes. Instead it had two quartz-synchronised direct drive capstan motors and two take-up motors with optical tacho-generators that also took care of the braking. The complete movement process was controlled by a microprocessor. This resulted in a previously unknown protection for the delicate cassette tape while at the same time achieving record-breaking spooling speeds. This precision drive was later to be built into the professional cassette machines.
The amplifier electronics had four Dolby™ B processors. With the MK II version, you could even switch between Dolby™ B and C. That together with the professional 3 head technology (sendust-ferrite), resulted in a perfectly "dolbyised" read-after-write. Two LED chains, each with 24 LEDs was ´built in to give optimal output control. The electronic press button control and an electronic counter with timer function ticked all the boxes when it came to operating the device.
In 1981, the Revox B170 was voted "Most outstanding new development of the year" at the Consumer Electronics Show in Los Angeles. Three years later at the same show in 1984, it was again voted "Most outstanding new development of the year in the area of magnetic sound and studio technology".
Revox B780, FM Tuner - Amplifier (1980 - 1984)
The idea of combining the technology of the B750 amplifier and the B760 tuner into a new compact device, the B780, appeared in the first instance to be a step backwards in the radio era, had there not been a completely new component in the mix. The secret was called "3278" and was a microprocessor whose 4 kB ROM concealed around 2,000 program instructions for controlling the B780. This microprocessor really played a part in all aspects of the device and there was scarcely an HF or NF component that didn't communicate with the microprocessor. This was why it was important to have the tune and amplifier next to each other.
The microprocessor enabled the press button control and a range of new processes such as scanning in both directions, numerical frequency input, storing 18 station frequencies and 7 antenna rotor positions, the electronic switching of inputs and outputs on the preamp, switching the speaker outputs, controlling the digital display, monitoring the outputs and a further raft of additional functions such as converting the de-emphasis, stereo filter, muting, etc. The "Microcomputer controlled synthesizer FM Receiver" was the start of a new era. There wasn't much left to improve in terms of the technical data. Operational comfort on the other hand, increased continually in significance.
After carrying out exhaustive tests on the Revox B780, Hans-Günther Beer wrote the following under the title of "Wonder boy", in the July 1980 edition of the German magazine "AUDIO": "The Revox receiver can be certainly be said to have an excellent price-to performance ratio. Where else can you get a tuner as good as that alongside such a high-quality amplifier, coupled with extremely high operator comfort for 3,000 marks?"
Revox B795, Record player (1979 - 1984)
With the B795, Revox offered a slightly downsized, lower priced version of the B790. At the same time, the design was changed and it was better matched to the metal finish of the hi-fi equipment. In addition, the slightly sloped operating bar was given a cleaner and clearer look. The savings to be able to reach a retail selling price of under 1,000 CHF were made possible by dispensing with the digital speed display and the speed fine control option.
On the other hand the weight of the turntable was practically doubled to 2.1 kg. The signal-to-noise ratio increased to 70 dB. The remaining technical data remained more or less unchanged.
Peter Thomas from the BBC in London achieved a particularly interesting application with the tangential pick-up arm. In order to be able to play Edison wax cylinders with the minimum impact on the cylinders themselves, he built an Edison player using the exceptional servo drive from the B795. The question of the cylinder drive was also elegantly resolved by using the capstan motor from a Studer A80 tape recorder, complete with its electronics.