KrupaX

Cheers Mike, that's all very good advice, I'll definitely bear it in mind - especially the bit about taking chips from the sockets before soldering... I think I'll probably give it a good while and a lot of thought, maybe an expert eye in person before taking any more action - the 6581s are getting 12 volts, I did check that right at the start as it seemed obvious... I might pull them and try then in a eurorack module I have to make sure they're not DOA... it feels as though all the buttons are fine tbh, and I haven't noticed any of the LEDs not lighting, just that they're not always indicating the right thing - controls like the envelopes and filters all seem to work ok.... I'm getting a lot, in fact most, of what I want from just MIDI CC control anyway fro now - sample tastic! thanks again, really good stuff to know, Chris

Hi, I've just come into possession of one of these; it works quite well over MIDI on the first three channels, but not the fourth (which is a pair of 6581s rather than the first three which are 8580s..) I haven't been able to determine any broken paths or components around the fourth voice, and have tested it with every MIDI channel in case that affected it - there's no noise at boot, though there is some clicking that can be heard when feeding it notes and CC data... It also has interface issues; the panel lights but each character is blanked / filled and while many of the knobs and buttons work, they're often unpredictable and not entirely reliable in various ways... Inspecting the wiring between the main board and the interface panel, it doesn't entirely look like many of the builds I've seen photos of; a good few wires lead from the main board directly to points higher up on the display board, rather than to the corresponding pin as it appears to do on photos I've seen here... one or two have broken away even with the very gentle manipulation I've given it, so maybe it's a lot of dry jointing (the unit was fully functional 10 years ago according to the previous owner / builder, but he's not inclined to fix it himself now - I guess his fun was had :) ) Is there a definitive build guide to be found anywhere? I'd like to unravel all this as soon as I can, but without some eejut proof guidance I might be a bit stuck! In any case, I'm probably going to seal it back up and MIDI control it so I can sample it to death in case I later muck it up somehow... In general, if resoldering this sort of PCB, is there some clever way to make it work nicely? - I've messed up before and not found enough metal to get a decent solder / contact to ... many thanks for any answers / guidance! Chris Krupa