Otari MX-5050
Parts →Accessories →

MX-5050 · an archive for the whole line

Keep your MX-5050 playing

Identify your machine, find its factory documents, and follow the work of keeping the whole MX-5050 line alive.

Identify by rear-plate code →Compare family photos ↓

−2010753210123+20406080100%VUOTARI
Ted's collection of labelled audio tape boxes

Why this site exists

Ted's tapes started this archive
Finding a way to hear my father's recordings led from one silver-faced machine to an archive for the whole MX-5050 line.

Read the backstory →

The Mini Pro's electronics open on the restoration bench

On the bench · MX-5050-2SHT

Restoring the Mini Pro
Bought listed as broken, then repaired, recapped and aligned. Follow the work and measurements as the project continues.

Follow the restoration →

Find your machine

Choose the closest family photo to open its identification page. Photos are a starting point; confirm the exact model from the rear identification plate before choosing a manual. Use the full identification guide →

Silver-face first-generation MX-5050 with two VU meters below the transportFirst generationMini Pro3 format examples1974–79Mark II recorder pictured in Otari's November 1976 preliminary specification sheet, with meter electronics above a horizontal tape deckMark IISeparate electronicsfrom 1977MX-5050B front panel from the 1979 brochure, with printed callout linesMX-5050BPlain Bby 1978B-II brochure photograph with a red electronic counter and two VU metersB-IIUprightby 1983Colour brochure photograph of the MARK III/2 with two meters in a raised rear electronics unitMARK IIIIncludes upright BQ-II4 format examplesfrom 1981B-III upright recorder from Otari's 1991 series data sheetB-IIIIncludes BQIII2 format examplesby 1990MARK IV tabletop recorder with meters raised behind the reelsMARK IVDesk-top3 format examplesby 1990

Read the original paper in a new way

Digital editions

Our linked transcriptions make factory manuals easier to search and navigate. Open the source PDFs alongside them to check the original pages, with selected figures restored for clear viewing.

First generationMaintenance Manual →BIIInstruction Manual →BIII and Mark IVOperation Manual →

Browse the whole document library →

Restored reel-table cross-section from an Otari maintenance manual
Test leads clipped to an MX-5050 during VU meter calibration

For the workbench

Service and repair

Find calibration guidance, documented OEM accessories, and possible donor machines for a part you can no longer buy new. A shared factory part number is a lead; check the fit against your machine before using a donor.

Explore service guides →Find donor parts →Check accessories →

Looking for period context? Browse the contemporary press archive →

Latest from the log

2026-09-24

The Mark II sheet arrived
The eBay copy of Otari's November 1976 Mark II preliminary specification sheet arrived on paper. Both pages are now scanned at 600 and 1200 dpi, transcribed as a digital edition, and used to replace the site's thin Mark II photograph and sparse specifications.

2026-09-18

Paper in the post
Six eBay lots bought in one run and due over the next month: two wanted cards filled, the first sales paper this site will hold for the eight-channel machine, a form number it has never recorded, and paper originals of the two books the library currently holds worst. All of it read off listing photographs until it lands.

2026-09-12

Zero in, zero out
The record side aligned for the first time — bias, record azimuth, record level, record EQ and SEL/REP — and the reproduce side run again underneath it, after a jumpy trimmer sent the session back to the meters and a channel reading 0.23 V turned out to be a pot, not a pad. The closing check: 1 kHz in at 0 VU, 1 kHz back off the tape at 0 VU and 1.23 V, both channels.

All log entries →