Circuit Overview:
Analog subtractive similar to OBXa in some ways but condensed yet more of course as technology matured. Michael Bacich notes: The OB-8 is still one of the finest synthesizers ever made. They pretty much got everything right. It was designed (mostly) by Marcus Ryle and Michel Diodic, who were very young engineers at the time. They later went
on to design the Alesis ADAT and many other groundbreaking products,then later started the Line6 company.
Service Tips:
I saw the strangest problem with this. Still need to get back and totally solve it. Intermittently computer slows down or something. I tried replacing what measured as BAD 7404 chips of whatever family they use. I put in same numbers that measured good on my chip checked..but as I did..various things started to get WORSE until I replaced the clock and it would not boot! I scraped the bad chips out of the trash and put them back in..bammo..boots up and works sort of ok again.! VCO chips fail sometimes also..More recently I found that good measuring 4051 chip was bad causing cv's to go out of bounds on one voice board. After replacing it worked...until I tried to trace the problem with the controls not responding and then apparently the DAC desided to bite it or the op amp buffer. Hopefully the latter. Here is a link to a page talking about the DAC and lots of other useful stuff alphaentek
Parts:
Aside from some of the Curtis chips and maybe CPU I stock everything all the time electronically. I've gotten the chips when needed from other techs or off ebay. Knobs may be difficult to find exact replacement. The switches are available from analogdiehard@att.net I hear.
Contact