MARK III

Otari's book for the half-inch four-track MARK III: ½″ tape at 7½ and 15 ips, in ten sections over 154 pages — general information, installation, operation, maintenance, routine maintenance and conversion, tape transport maintenance, performance testing and electronic alignment, major component replacement, troubleshooting, and parts lists and schematics. OS3-035 is on the cover and again in the standard-accessories list. The manual prints no date of its own; a drawing near the back carries 22 DEC 1983 in its title block.

It also carries an addendum headed “(MX-5050 BQ-2, MK-3-4, MK-3-8)”: one sheet of changes for the BQ-II and both half-inch MARK III machines together. The copy has a text layer, and every page carries a “Downloaded from www.Manualslib.com” line from the copy it came from.

The book for the BQ-II, the MARK III series' quarter-inch four-track: ¼″ tape, four tracks at 0.94 mm, 7½ and 15 ips. Ten sections over 130 pages, in the same order as the MKIII-4 manual, from general information and installation through tape transport maintenance, performance testing and troubleshooting to parts lists and schematics. The catalog numbers are neighbors too: OS3-031 here, OS3-035 there.

Know what this copy is before relying on it. It is not a scan but a retyped transcription, laid out in Word with the figures pasted in as images, and typing errors came along — Table 1-2 lists an “Extension Board Ashley”. Even the catalog number is a reading: the accessories table and a packing list both give it as “053-031”, which reads as OS3-031.

Otari's ten-page brochure for the desk-top family, © 1984: a page each for the MARK III/2 two-channel, MARK III/8 eight-channel and MARK III/4 four-channel recorders, then remotes, accessories and options, and a comparison grid across the MARK III/2, III/4, III/8 and the upright BQ-II — channels, tape width, speeds, equalization, frequency response, signal-to-noise, and wow and flutter.

Its accessory list says which machine each part fits: the RK-2B rack kit for the BQ-II, the CB-102 remote for every 5050 except the MARK III/8. Pages 33–42 of worldradiohistory.com's Otari catalog bundle.

The first printing of Otari's two-sided sheet for the Model 5050 MARK III/2 ¼″ two-channel recorder, © 1983 from Belmont. Its performance figures match the 1984 B-II sheet's — the same speed pairs and four-head stack, wow and flutter under 0.04% at 15 ips, 72 dB unweighted signal-to-noise, 25 Hz to 22 kHz at 15 ips — as a machine sharing the B-II's heads and audio board should. It adds a vinyl-covered wood case, the RK-32 rack kit, a 34-pin external control connector and an 89 lb shipping weight.

Pages 7 and 8 of worldradiohistory.com's Otari catalog bundle.

The same sheet reprinted four years on, © 1987, form BP6872.5K — and the figures moved. Signal-to-noise now reads 68, 71 and 69 dB unweighted at 15, 7½ and 3¾ ips, against 72, 72 and 70 in 1983; frequency response is 30 Hz to 20 kHz at both 15 and 7½ ips, against 25 Hz to 22 kHz and 20 Hz to 20 kHz; and the measurements move from 3M 226 to Ampex 456 tape. The features list now describes the external control connector as an interface for SMPTE/EBU time-code synchronizers and editors.

Pages 23 and 24 of worldradiohistory.com's Otari catalog bundle.