What it is
The MX-5050BII is the generation after the MX-5050B, on sale by 1983: the earliest dated Otari paper for it is the 1983 5050B-II brochure and Edition 3 of the instruction manual, issued March 1983 (scan). Its upright outlined MX-5050 front badge differs from the BIII's embossed silver plaque; neither badge prints the model suffix (identification guide). The BIII was introduced to replace it in 1990 (the B-III's history). The B-II's own press record is on its History page.
People sometimes call the BII a "MkII", though Otari's earlier MARK II is a different machine. The wider family argues the distinction at length. This page exists so the argument has the BII's own paper behind it.
Its factory book describes a DC-servo direct-drive capstan running two speeds, 15 and 7½ ips, user-convertible to 7½ and 3¾ (specifications, p.1-5), two six-pole induction reel motors, active balanced input and output circuits, a built-in two-frequency test and cue oscillator, motion sensing, an edit control, a memory stop, and a computerised elapsed-time indicator with an LED display. The amplifier panel carries a reference flux level indicator and a standard reference level output switch — the front-panel descendants of the SRL trimmers the Mini Pro hides behind two holes in its faceplate.
Specifications
Only what this site's own copy of the factory book states. Table 1-1 of the instruction manual, in its own terms:
| Model | Head format | Speed | Tape |
|---|---|---|---|
| BII-2 | 2-track, 2-channel | 15 and 7½ ips | ¼″ |
| BII-4 | 4-track, 2-channel | 15 and 7½ ips | ¼″ |
| BII-F | Full track, mono | 15 and 7½ ips | ¼″ |
| BII-2E | 2-track, 2-channel DIN | 15 and 7½ ips | ¼″ |
Read the second row carefully. The BII-4 is a quarter-track, two-channel machine, not a four-channel one. Otari's suffix digit counts tracks, not channels, exactly as it does for the 4SH — the Specs page makes the same point about the first generation.
All four convert to 7½ and 3¾ ips by the procedure in the manual's section 6.4 (Section VI).
Have one, or paper for it?
The book is here; the machine is not. A BII owner with a rear plate, a head-block photo, or the separate service documentation would turn this from a page about a manual into a page about a recorder. See how to contribute.
Sources
B-II documentation
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Instruction manual, OS3-038 — Edition 6, September 1984. Table 1-1 for the model list, Section 1.1 for the system description, p.1-5 for the two speed pairs, section 6.4 (Section VI) for the speed conversion.
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Instruction manual, OS3-038, Edition 3 — the cover, "Edition No. 3 Issued Mar. 1983".
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5050B-II brochure (1983) — © 1983. Page 8 lists the two-channel machine's accessory codes.
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5050 B-II data sheet (1984) — form BP6847K. Page 2 independently lists the two-channel options.
Period catalog
- Video Images catalog (1988–89), Otari listing — a local copy of the catalog cover and original page 252, listing CB-102 for the MX-5050 series except MARK III/8 and FC-2B for B-II/BQ-II. Its family wording does not establish a separate BII-2 fit; the model-specific Otari sheets above do. The complete 460-page catalog remains at WorldRadioHistory.
B-III and MARK family references
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MX-5050 Series data sheet OA-321C — © 1991, the earliest dated paper for the B-III. The scan is at /manuals/otari-mx5050-series-data-sheet-1991.pdf.
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Service training binder — head assembly KH-41IA serving "BII2, MKIII-2", the cross-reference that ties this machine to the MARK line.
Wider family context
- The wider family — why a MkII is not a BII, and where the BII sits in the line.