Because it was expensive compared to other consumer models and had exceptionally good mechanical performance and durability, the B215 was used primarily by professional customers—radio stations, recording studios and real-time[a] cassette duplicators.

The B215 differed from the B710 and competing decks of the period in having an unusual, computer-like control panel and elaborate automation performed by three Philips microcontrollers.

Objective, independently measured and verified specifications of the Revox matched or surpassed those of the best competing decks; comparative tests placed the B215 on the same level as the Nakamichi Dragon and above the flagship models by ASC,[b] Harman Kardon, Tandberg or TEAC.

Reviewers praised the Revox for its exemplary mechanical quality and the expected durability of its tape transport, but criticized it for lower-than-expected dynamic range and shortcomings in usability.

Studer AG, a privately owned Swiss manufacturer of professional audio equipment, began development of high fidelity cassette recorders in late 1970s.

[1][2] However, the decline of reel-to-reel recorder sales, the commercial success of Nakamichi and "designer models" by Bang & Olufsen, coupled with pressure from within the company, persuaded Studer to invest in the cassette format.

[2] Marino Ludwig, designer of the Revox B77 reel-to-reel recorder,[3] examined the best cassette decks on the market and advised Studer on a course of action.

[2] The B710 stood apart from the competition in having a true, four-motor direct-drive tape transport: each of the two capstans and the two reels were driven by their own electric motor without any intermediate belts, gears or idlers.

[1] Marino Ludwig wrote that the development coincided with a flood of new features (German: der Flut von Neuheiten) introduced by the Japanese, and only a few, like automatic tape type recognition, could be implemented within the deadline.

[8] A professional derivative, the Studer A721, was very similar to the B215 but was equipped with balanced inputs and outputs, and traditional rotary volume controls in place of up-down buttons.

[11] Ludwig wrote that the price decrease reflected cost savings achieved through the use of larger printed circuit boards and automated assembly.

[15] The improved, cosmetically redesigned B215S, introduced in 1989, was priced at $2800–$2900[14][15]—more than the Dragon, and three to four times more than contemporary flagship decks by Onkyo, Pioneer or Sony.

[16] New Revox-branded cassette decks sold under Harman management, the consumer H11 and the professional C115,[17] were in fact rebadged Philips FC-60 / Marantz SD-60 models, and had nothing in common with the Revoxes of the past.

[20] The enclosure measures 45 by 15 by 33 centimetres (17.7 in × 5.9 in × 13.0 in)[20] and is a standard Studer pressed steel box with two internal stiffener rails that carry the tape transport.

[23] Tape transport and recording mode controls, placed on the upper aluminum strip, are visually set aside from secondary buttons.

[29] A Revox deck works differently, directly driving each capstan with its own motor, equipped with a massive flywheel and a 150-pole speed sensor.

[31][c] In 1985, the only other deck with a similar direct-drive arrangement was the five-motor Nakamichi Dragon (the nearest contender, the four-motor Tandberg 3014, used a single capstan motor).

[34][22] According to Howard Roberson of Audio magazine (USA), operation of a new B215 transport "...was very quiet, even in play mode - perhaps the quietest of any deck ... tested to date... very well constructed, with a definite look of long-term reliability".

[41] Subtle phase control networks in the active filter were tuned to best possible step response; Ludwig wrote that they enabled "square-wave reproduction off the tape of truly professional quality".

[43] Finally, a CMOS multiplexer, coupled to a low-Q bandpass filter centered on 4 kHz, selects the desired mid-range equalization setting.

The third microcontroller manages the digital-to-analog converters, CMOS switches, multiplexers and recording level meter; it executes the tape calibration program and stores current settings in non-volatile memory.

[52] Meinrad Liebert criticized the IEC for failing to impose strict standards: the organization simply followed the market, periodically adapting its set of reference tapes to arbitrarily chosen "industry averages".

[50] Unchecked spread of incompatible cassettes made traditional fixed-bias decks almost unusable for recording; this, according to Liebert, explained sudden demand for calibration features that did not exist in the 1970s.

For example, the B215's wow and flutter rating of 0.1% is a maximum value interpreted according to DIN 45507 / IEC 386,[56] while the competitors usually provided far lesser root mean square (RMS) numbers.

[44][36][28][58] Craig Stark of Stereo Review admitted that the figures were so close to the limits of test instruments that any measured differences between the decks in this class were probably immaterial.

[44] Long-term absolute speed, typically for all quartz-controlled double-capstan transports,[g] was consistently 0.2–0.3% faster than standard, and almost insensitive to fluctuations in mains voltage.

Howard Roberson of Audio suggested that the narrow overload margin of the Revox was a price paid for its wide frequency response.

[21][61] Replay frequency response, measured with test tapes, is exemplararily flat,[21][61] on a par with the Nakamichi Dragon, and noticeably better than the Tandberg 3014.

"[28] In comparative tests by Stereo Review (United States, 1988) and Audio (West Germany, 1985), the B215 was ranked one of the two best decks on the market, the other being the Nakamichi Dragon.

[58] Sonically, both the B215 and the Dragon surpassed equally expensive ASC[b] and Tandberg decks and the much cheaper flagship models by Harman Kardon, Onkyo and TEAC.