Models

Seven generations on one platform. Start from your model code or a photo, or pick your generation below.

Have the code from the rear plate? →Type it in — e.g. MX-5050-2SHTD₂ — and get the machine, with every letter explained.No plate? Identify by photo →Compare the generations side by side, with the tell-tale features of each.

Uprights

First generation

1974–79 · 2S · 4S · QX · F · 8

The early line spans the silver-face upright, four-channel QX and half-inch eight-track. Some wide-format machines carry their electronics separately; capstan drive depends on the model.

MX-5050B

by 1978 · B-2 · B-4 · B-F

Three speeds, TTL logic. The generation where the suffix letter matters more than the B.

B-II brochure photograph with a red electronic counter and two VU meters

MX-5050 B-II

by 1983 · BII-2 · BII-4 · BII-F · BII-2E

The workhorse. A microprocessor counter, selective reproduce on every channel, and the heads and audio board it shares with the MARK III/2.

B-III upright recorder from Otari's 1991 series data sheet

MX-5050 B-III

by 1990 · BIII-F · BIII-2 · BIII-2E · BIII-P · BQ-III

The last uprights, and the upright four-channel BQ line continued as the BQIII.

Desk-tops and separate electronics

Mark II

from 1977 · II-2 · II-4

Otari's second chassis: the electronics lifted out of the deck, and the DC servo made standard. On sale beside the silver-face machine, before the B existed.

MARK III

from 1981 · III/2 · III/4 · III/8 · BQ-II

The line that grew backwards: the half-inch eight-track first, the four-track next, the quarter-inch two-track last — and the BQ-II, the series' four-channel upright, introduced in January 1981.

MARK IV

by 1990 · MKIV-2 · MKIV-2E · MKIV-4 · MKIV-8

The last desk-tops, and the widest formats Otari put on the 5050 platform.

Model designations

This index gathers documented model designations, including names from sales paper and manuals; not every spelling has been checked against a physical rear plate. The suffixes are speed and capstan, not different recorders: H is 15/7½ ips, L is 7½/3¾ ips, D is the DC capstan servo, E is DIN equalisation, T is output transformers, and ₂ marks the separate-electronics machines. Every string below resolves to the machine documented under it.

27 machines. One thing is still unsettled: the B-4. Otari gives its speeds and its amplifier board, but never prints how many channels it records.

Every document, all generations →

Contribute

Every dashed card on these pages is a document this site does not hold: manuals, brochures, spec sheets, rear-plate photos. Contributed scans are credited on their card in the Library. Corrections to any page are welcome too.

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