Ibanez CS-9 Stereo Chorus

Jered · January 20, 2009, 04:28:21 PM

Does anybody have one they can open up and get the settings of the two trimmers? I'd really appreciate it.
Thanks, Jered

iaresee · January 20, 2009, 04:49:26 PM

I've owned three CS-9's over the years and the trim pots were set differently in each one. No doubt they're used to bias some piece of the circuit. Sorry that's not a terribly helpful answer. Maybe there's a biasing guide for them hidden on here some place?

Jered · January 20, 2009, 10:11:51 PM

Damn. Well if anybody can help me out with target voltages I'd be greatful. Schematic is here:
http://www.schematicheaven.com/effects/ibanez_cs9_stereochorus.pdf
Thanks guys

Jered · January 21, 2009, 06:52:18 PM

Nobody?

iaresee · January 21, 2009, 09:39:37 PM

Wish I could help you. Looks like one of them is VR101 -- it's near the label that says CLOCK. And the other is VR102 near the label that says BIAS.

What if you start at noon on both and tweak from there?

Jered · January 21, 2009, 11:25:01 PM

I've been reading all the MN3102 and MN3207 info I could find but its limited because these chips are out of production. I tried dialing it in by ear but it just isn't right. If nobody here can help I guess I'll try commonsound and ampage.
Thanks.

oskar · January 22, 2009, 12:08:56 AM

I don't think any of them are set for a voltage originally. Guessing here but the clock trimmer is probably set for a specific clockrate at max potentiometer action. Like this CF-7 instruction...
http://www.ibanez.com/parts/2004_PARTS/electronics/tonelok/other/CF7_adjust.html
The other trimmer could have been set with a sinewave and a scope to allow for maximum signal before clipping.
Hope that was of any help...

Jered · January 22, 2009, 03:00:53 AM

Thanks Oscar. That just might be enough info to get me there. Thank you very much.

News:

Ibanez CS-9 Stereo Chorus