Scully 280B
A pro tape machine advertised with a number instead of a name, and a 72 dB signal-to-noise claim that nobody else could match.
Overview
Scully built the 280B as a professional recorder/reproducer. When the company announced it in 1973, it leaned hard on one figure: a signal-to-noise ratio of up to 72 dB at mastering speeds. The advertising copy in Recording Engineer (June 1973, p.36) made the boast plain - nobody else could give you an S/N ratio up to 72 dB. It also framed the machine's simple model number as a deliberate contrast to fancier names on the market. The same announcement described the 280B as having completely redesigned electronics and a new tape motion sensing system.
The motion sensing system was called OPTAC. It was an optical scheme that did away with the deck plate sensor mechanisms common to earlier transports. Scully also reworked the electronics around what it described as a mother-daughter board layout, with all test and adjustment points readily accessible for maintenance. DB Magazine (May 1973, p.20) reported the same two headline features, redesigned electronics and the new tape motion sensing system, and specified bandwidth as essentially flat, within ± 2 dB from 30 Hz to 18 kHz.
The 280B appeared in multiple configurations. A separate 280-B listing notes an AC motor variant running 7½/15 ips in a console. These are used-market listings, not manufacturer documentation. Treat the configuration details as a sample of what actually circulated, not a complete catalog of factory options.
The 280B belongs to the professional broadcast and studio world, not the home hi-fi world. It was sold into facilities that ran tape all day, and the design priorities (maintenance access, motion sensing, headroom in the electronics) reflect that. At the time, the 72 dB figure was a genuine differentiator for a mastering-speed machine, and Scully's advertising treated it as the whole story.
Original pricing is likewise not documented here. The only figures in the available material are 1980 classified asking prices for used machines, which say nothing reliable about what the 280B cost new.