Build Your Own Clone Message Board

The pedal works fine with the battery but hums loud and produces a very weak fuzz signal when I try to use an external power supply.

give this a quick read: http://www.buildyourownclone.com/board/viewtopic.php?f=51&t=6108

it sounds like something simple, but we'll really need to see some pictures.

If your power supply is an unregulated generic wall wart type throw it away. These should never be used to power an audio circuit. If you don't know if the PS's output is regulated or not measure it's output with nothing attached to it. If it is regulated the output will be within 1/10 of a volt or so of it's rated output. If the output is 12 to 13 volts or higher it is unregulated and should not be used. Your PS may work with other pedals but that doesn't necessarily mean it will work with ALL pedals. Some pedals have better on board PS filtration than others.

Here are three pics. Hope this helps.

those are about best pics i have every seen. everything looks to be in order, did you see what stephen was saying about the wall wart?

Since the battery power routes up through the DC adapter jack, it's using the same circuitry to power the pedal as the wall wart does. So if the pedal works perfectly with a 9V battery and not the wall wart, the problem is almost certainly with the wart.

I went through my collection of wall warts and most of the 9v warts read between 12 and 13 volts. But I found one that read 8.75v and tried it. Same hum. Since these warts work on my other pedals I'll just keep a battery in the fuzz. Thanks for your help.

Seems like an opportunity for a BYOC multi-output power supply kit. Or at least a pre-built, BYOC approved, supply, available from BYOC.