Boss CS-3 power/noise problem

[jpiddy118]

Got called up for a country gig this weekend, hadn't fired up this pedal in a couple years... never had a problem with it before (black label MIJ model). As first pedal in my chain, with isolated 9v from a Cioks DC5, the LED only lights dimply, and there is a horrible distortion underneath the notes, which increases when the sustain knob is turned up (pedal passes buffered signal fine in bypass). After unplugging 9v supply and popping in a battery, the pedal worked fine for a few moments, but the noise gradually comes back. Any experience with this or thoughts??

Thanks,
JP

[GGBB]

Older boss pedals were designed for use with their ACA power supply which was an unregulated "9V" supply that actually put out about 12V. Internally those pedals drop the voltage a bit to compensate for the over supply, so when they are fed a true 9V, they end up not having enough voltage. There is a simple mod to make it work with 9V. Check the label on the back to be sure yours is an ACA unit, but I'm pretty sure anything Japanese made would be in the that category - my Taiwanese CS3 is ACA and was made later than the Japanese ones.

[digitalzombie]

I concur with this. I bought a used CS-3 a while ago, demoed it at a guy's house with a battery and it was fine. Got it home and plugged it in to my power supply and it acted exactly as you describe. You either need the correct adapter, or if you have a Voodoo Lab Pedal Power you can flip  the DIP switch to the on position and that'll work.

[GGBB]

Here's some more technical explanations along with mod instructions. Thanks Stinkfoot (one of my favorite sites).

http://stinkfoot.se/archives/726
http://stinkfoot.se/archives/1019