Otari MX5050 B2HD Fully Rerstored 1/4" Mastering Tape Deck, JRF Heads, A Gem!

OTARI MX5050 B-2HD 2-Track/4-Track Professional Mastering Reel-to-Reel — Extensively Restored — JRF-Lapped Heads — 3 Speeds

This Unit

This Otari has received an extraordinarily thorough restoration — more overhaul than routine servicing. On the mechanical side: takeup tension arm relubricated and readjusted, I/O converted to pin-2-hot standard, supply and takeup reel turntable heights adjusted, deteriorated rear panel foam replaced, rubber bumpers installed on the rear chassis, counter and direction belts replaced, meter bulbs replaced, mute and record relays replaced, speed and EQ curve switches cleaned, pitch control pot/switch replaced, pinch roller replaced with a high-quality used unit, capstan and pinch roller lubricated, SRL LED replaced, and spring-loaded NAB reel hub adapters added. Heads were professionally lapped by JRF Magnetic Sciences; their full test report (included in the photos) shows all four heads passing final inspection with excellent inductance and DCR figures.

On the electronics side: complete power supply rebuild with new diodes, bridge rectifiers, and capacitors; all nine ICs replaced; all remaining electrolytic capacitors replaced; all seven transport control relays and flyback diodes replaced; multiple corroded and cold solder joints desoldered and resoldered; all male connectors resoldered. The unit was then fully aligned at 250 nWb/m.

The technician describes this restoration as complete enough that the deck performs essentially like new, both electronically ("It's +/- 0.5dB all the way to 20k. 2dB bump @31.5 hertz. Not terribly far from an ATR.") and mechanically. Cosmetically, the unit shows a light patina consistent with careful handling over several decades — this is a working professional tool, not a display piece, but it presents very well for its age with no significant cosmetic issues. 

About the Otari MX5050 B-2HD

The Otari MX5050 series was built for broadcast, recording studios, and mastering houses rather than home hi-fi use, and it shows — this is a genuinely professional-grade machine, engineered for continuous duty and long-term reliability rather than living room aesthetics. The B-2HD configuration offers 2-track record capability with both 2-track and 4-track playback, making it a flexible choice for both original recording work and playback of quarter-track consumer tapes.

Direct-drive, servo-controlled capstan (no drive belt in the capstan path) delivers the speed stability professional mastering work demands. The three-motor transport — a capstan drive motor plus two reel motors — combines with heavy-duty logic transport control for smooth, reliable operation across all three tape speeds.

Balanced XLR inputs and outputs, adjustable output level and equalization curve (IEC/NAB) switching, adjustable record level, and mic attenuation round out the rear panel. The MX5050 accepts up to 10.5-inch reels and includes a built-in splicing block and cueing lever.

Verified Specifications

• Track system: 2-track/4-track configuration (2-track record; 2-track and 4-track playback)
• Heads: 4 total — erase, 2-track record, 2-track playback, 4-track playback
• Motors: 3 — direct-drive servo-controlled capstan motor, 2 reel motors
• Tape speeds: 3¾, 7½, and 15 IPS (defeatable variable pitch at all speeds)
• Reel capacity: up to 10.5-inch reels
• Frequency response: 30 Hz–18 kHz (7½ IPS, ±2dB); 35 Hz–22 kHz (15 IPS, ±2dB)
• Wow & flutter: less than 0.05% (NAB weighted)
• Signal-to-noise ratio: 62 dB (unweighted)
• Crosstalk: greater than 55 dB
• THD: less than 1% at 1 kHz, 200 nWb/m
• Inputs: -15 dBm line, -70 dBm mic (balanced XLR)
• Outputs: +4 or -10 dBm (balanced XLR)
• Power: 117V AC, 50/60Hz, 100W
• Dimensions: 21½ x 21 x 17" (546 x 533 x 432mm)
• Weight: approx. 51 lbs (23 kg)

📦 Worldwide shipping available – Securely packed and insured. Local pickup near 01810 also welcome.
Quoted international shipping rate is to Australia, the furthest destination from my location in the USA. Please inquire for shipping rate to your particular non-US address. The package will be large, heavy, delicate, and insured for full value, so shipping may be a significant expense.