“Vintage 1972 TR-33 Rhythm Machine by Roland. In good condition given its age. Please see pictures. I have taken close ups of any nics I see.
Will send a link to a 26-page manual that includes schematics with purchased item. Also had an 1/4 stereo plug output and potentiometer output for volume at the rear. The TR-33 is a drum machine analog transistor (TR = Transistor Rhythm).
Has sounds such as bass drum, cow bells, bass drum, congas, claves, rimshot and more. It uses a circuit “resonance granted” (Tuned Resonance). Through modulation of a white noise generator, it has sounds like the snare, high hat, maracas and cymbals.
The TR-33 and it’s sisters, the TR-55 and TR-77 were the first products of their brand. The TR-33 was initially designed to be mounted under the keyboard of an organ or piano; hence the “L” shape. ” Click here to visit listing on eBay