Terecorder M6

Akai M6 Tape Recorder

The Akai M6, also marketed as the Terecorder and the “Multi-Four” in the UK, is a quarter-track stereo tape recorder designed for both advanced performance and versatile operation. It supports both vertical and horizontal use, and offers three tape speeds—with a maximum of 15 inches per second (ips)—enabling high-fidelity recording and playback.

Drive and Transport:

• The M6 features a large hysteresis synchronous motor that ensures extremely stable tape motion, resulting in a wow and flutter rating of just 0.07% RMS, notably low for its era.
• Rewind speed is efficient, capable of rewinding a 1,200 ft reel in approximately 2½ minutes.

Amplification and Monitoring:

• The machine is equipped with two identical valve amplifiers (marked “left” and “right”), a design inspired by the Ampex 601.
• Each amplifier delivers 6 watts per channel and can independently drive an 8″ coaxial extension speaker (optional), which also serves as the unit’s transport lid when clipped together.
• The upper (left) amplifier powers a built-in loudspeaker for onboard monitoring.
• Extension speaker sockets are provided for both channels, enabling stereo playback through external speakers.

Inputs and Outputs:

• Inputs:
  • Low-level, high-impedance microphone input
  • High-level line input
• Outputs:
  • High-impedance head output (for connection to external amplifiers)
  • 8/16 ohm amplifier output (for driving external speakers)

Audio Performance:

• Signal-to-noise ratio: Better than -45 dB
• Crosstalk: 80 dB at 1 kHz
• Quarter-track stereo format allows for extended recording time and flexible playback options

Here you find 620 models, 574 with images and 202 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Akai Electric Co., Ltd.; Tokyo