OBERHEIM SYNTH group photo

Yahoo Groups archive

OBERHEIM SYNTH

Index last updated: 2026-04-28 23:39 UTC

Message

Re: M6R Help

2019-11-06 by andy.birko@...


Thanks - I've already swapped the 3396 and the problem stayed with the voice, not with the 3396.

I just ordered a semi ok scope from banggood but it won't be here for a few weeks. Those IC's are cheap so I might just order some up anyway. I might wait until I get the scope so I can actually see where the fault is rather than just shotgunning parts. Knowing that might also be able to help someone else down the road.

I posted this on another group too (M6/1000 FB group) and someone else suggested the MUX right away

Anyone know if there's a *readable* scan of the M6 schematics somewhere? I found a re-drawn version for the M1000 which is probably the same but just in case.

Also, one last question - have I assumed correctly that pins 4 & 8 are the clock input for the DCOs on the 3396?

Thanks!

---In oberheim@yahoogroups.com, <mrspring_eire@...> wrote :

Swap the CEM chips about, and see if the fault moves with the chip.

If it's the channel and not the chip, then replace the MC14051BCP (8 channel mux/demux chip) and/or the 74HC32N (quad 2 input "OR" gate) - worked for me on my M6 when a voice channel went mad.

I have never personally seen a 'wide body' 3396 go bad, but the 'slim body' version as found in the M1000 has had a very poor record for me, with 5 out of 6 failing in my 1000 over time.




Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.