USED UNIT, SERVICED AND IN WORKING CONDITION In the early '60s, before Japan had established itself as the electronics juggernaut it would become, Akai introduced "Roberts" – rebadged Akai gear designed to appeal to Americans. The 770 was one of the first, essentially an Akai M-7 with cross-field heads. While the Roberts 770X is fairly common, the early 770 with built-in tube amp is a fairly obscure 4-track deck. Factory Specs Type 4-track, 2-channel, stereo/monaural open reel tape system Heads 1 x record/playback, 1 x bias, 1 x erase Motor 2 speed hysteresis synchronous Reel size up to 7 inch reel Tape speeds 1 7⁄8 3 3⁄4 7 1⁄2 ips Wow and flutter 0.15% (7 1⁄2 ips) Frequency response 40Hz to 23kHz (7 1⁄2 ips) Signal to Noise Ratio 40dB Total harmonic distortion 3% Crosstalk 53dB Output 800V (line) Speakers 5 x 7" oval Valve complement 2x EF86, 2x 12AD7, 2x 6BQ5, 2x 6X4, 1x 6AR5 Dimensions 20.08" x 13.39" x 8.90" Weight 47.40 lbs.
