Akai M6

The Akai M6 reel-to-reel tape deck is a quarter-track stereo recorder from the early 1960s (1961-1964), boasting advanced features for its time and tube electronics. 

It offers 3 tape speeds: 3¾, 7½, and 15 inches per second (ips), with a maximum reel size of 10.5 inches. The machine employs two permalloy heads in a stereo configuration and uses a large hysteresis synchronous motor, which results in an exceptionally low wow and flutter of less than 0.07% at 7½ ips. The signal-to-noise ratio is better than -45 dB, providing good audio fidelity. 

It outputs 6 watts per channel through two separate amplifiers, each driving an 8-inch coaxial speaker (extension speakers available that can clip together as a transport lid). The design allows vertical or horizontal operation, and it has inputs for low-level microphones and high-level line signals, plus outputs for external amplifiers or speakers. 

The deck includes automatic stop and rewind features, and its wooden cabinet dimensions are about 14 x 20½ x 8½ inches, weighing around 47 lbs (21.4 kg). It uses 9 tubes and has an NAB equalization standard, reflecting its vintage tube-based hi-fi technology and solid build quality for consumer use at the time