Circuit Overview:
A digital synthesizer which utilizes special processing chips designed to support Yamaha's FM synthesis architecture. 4 operator scaled down DX7. I really suspect they released this with the Blah sounds just to give people a bad reference floor so that they would buy a DX7. :-) Whatever they did, it worked. I've heard figures that they sold about a million units of them...I'm not sure if that referred to the entire series or just the early ones (DX-1 through -9). Anyone?
Service Tips:
I've found most of these units to be fairly rock solid circuitry wise. Abused units sometimes have solder problems. I've fixed the few I've had in by just going over suspected areas of the circuit boards on related synths (DX7's).
Parts:
While Yamaha normally does not keep parts around more than 5 years or so. I try to stock what I can. Out of dx knobs.
Contact Sound Doctorin'