Hey, you technically knowledgeable Moog guys.
The chorus section on the ol’ Opus seems to be on the fritz. For instance, with the chorus depth all the way up, the string voice sounds like just a saw with a slight degree of vibrato, instead of lush and… chorusy… as it usually is. It’s only done this since I powered it up a couple days ago… i took a peek inside and I can’t see anything physically wrong.
Any ideas? Thanks in advance for any insight!
In my professional opinion: It’s broken.
Seriously, you’ll probably need someone to fix it.
Bad chorus driver chip or capacitor would be my first guess, but it could be any number of several things.
If you gigged with it last, brought it home and now it doesn’t work, it could even be a cracked PCB.
The Opus boards aren’t all that strong.
My eyes lit up when I saw it was you who responded, Kevin. But ugh… that’s a more dour outlook than I was hoping for, but i imagined it was a component issue.
I have been inside it, and like i said, nothing physical jumped out at me (no cracked boards or burned-out things that I could readily see). Which capacitors should I be looking at? Or should I recap the whole damned chorus board? I wouldn’t mind doing something relatively simple like that, at least to rule it out. Any guidelines?
I wish I could offer some advice on what you could do, but it’s likely a component and a classic “schematics and scope” type troubleshooting example.
Guessing at what’s wrong, even with a small list of possibilities provided may make things worse and end up costing more.
I can provide a PDF of the service manual, but someone with a scope and some troubleshooting skills are what’s really in order.
Do you have a tech in your area that you trust?
I think you’re right. I take apart some pots and clean ‘em and suddenly I think i’m actually QUALIFIED to work on these things… tee hee. I shouldn’t be fuckin’ with capacitors.
I also think I read someone saying there are no good techs in the Seattle area. I know museslave and eegeek are from around here, I think one of them said it. I hope it’s not true… hey, I’ve got an idea…
…everybody, see my next post. 
…although, Kevin, I WOULD love a .PDF of that service manual.
I think I found a guy who can diagnose this thing. I’ll show this to him.
Thanks a million, Kevin!
