It was produced in the period from 1979 to 1980. It is a model of the company Akai with the logic control system "IC logic" and noise reduction Dolby. With 12 holes on the head block cover, the Akai GX-635D is similar to the GX-266D. The recorder has a speed adjustment, as well as the ability to mix a line signal and a microphone. It was the first tape recorder with a mechanical counter of real time (only for a speed of 19 cm / s).
A reverse selector is also installed, which reacts to the installed metal foil on the film passages. The linear output is adjustable.Akai GX-635D has six heads, one for the main motor and the drive shaft 2 for reel motor. There are two color variations: silver and black. This model was extremely popular, and still occupies the top lines of resale all over the world.