Akai M7

The Akai M7 reel-to-reel tape deck is a mid-high fidelity, four-track stereo recorder made in Japan between 1964 and 1967. It features tube electronics and uses the NAB equalization standard. The tape deck supports tape speeds of 1 7/8, 3 3/4, and 7 1/2 inches per second with a maximum reel size of 7 inches. It employs three permalloy heads—record/playback, bias, and erase—configured for four-track stereo operation. The M7 uses a single hysteresis synchronous two-speed motor with capacitor start.

Key technical specs include a wow and flutter under 0.15% at 7 1/2 ips, frequency response between 40 Hz and 23 kHz (±3 dB at the highest speed), and a signal-to-noise ratio of around 40 dB. Total harmonic distortion is under 3%, and channel crosstalk is about 53 dB. The machine outputs 6 watts per channel through tube amplifiers to either internal or optional external speakers (two 8-inch coaxial extension speakers available). Inputs include low-level high-impedance microphone and line inputs, with multiple input jacks for microphones, pickups, and phono/radio sources. It also features two large VU meters for level monitoring, and controls for volume and tone for each channel.

Physically, the deck measures about 14 x 20.5 x 8.5 inches and weighs approximately 47.3 lbs. It can be used both horizontally and vertically, with a rugged wooden cabinet construction. Notable is the world's first cross-field bias recording system used in this model, enhancing sound fidelity.