This is a service manual for the Sony MZ-R70 portable MiniDisc recorder
The Sony MZ‑R70 Service Manual provides detailed technical data, safety warnings, and step‑by‑step repair instructions for the portable MiniDisc recorder. It includes specifications such as laser diode characteristics, audio input/output levels, power requirements, and battery life, as well as a complete parts list and exploded views.
The manual also contains service notes, disassembly sequences, test mode procedures, and electrical adjustment guidelines, helping technicians diagnose and fix issues while ensuring compliance with safety standards.
| Frequency response | 20 to 20,000 Hz + 3 dB |
|---|---|
| Wow and flutter | Below measurable limit |
| Microphone input level | 0.35‑1.38 mV (stereo mini‑jack) |
| Line‑in input level | 69‑194 mV (stereo mini‑jack) |
| Optical digital input | Optical (digital) mini‑jack |
| Audio output level | 5 mW + 5 mW into 16 Ω (stereo mini‑jack) |
| Dimensions | ≈ 81 × 74 × 26.2 mm (W × H × D) |
| Mass (recorder only) | ≈ 115 g |
| Laser diode wavelength | 790 nm |
| Laser output power | < 44.6 µW (measured at 200 mm) |
| Power requirements (US model) | 120 V AC 60 Hz |
| Power requirements (UK/HK model) | 230‑240 V AC 50/60 Hz |
| Battery type (rechargeable) | Nickel‑cadmium (NC‑WMAA) |
| Maximum recording time (MDW‑80 stereo) | 80 minutes |
| Maximum recording time (MDW‑80 monaural) | 160 minutes |
| Maximum recording time (MDW‑74 stereo) | 74 minutes |
| Maximum recording time (MDW‑74 monaural) | 148 minutes |
Up to 80 minutes of stereo recording can be made on an MDW‑80 disc.
The US model requires 120 V AC at 60 Hz.
The optical pick‑up uses a GaAlAs laser diode with a wavelength of 790 nm.