Need help with a stompbox/noise problem....

Hey,

I built 2 of the Sansamp GT-2 and I just got a Radio Shack 9V 800ma power supply. When I run each off of their own 9v battery I don't have any noise.
But, after I wired the in parallel off of the same 9v power supply it sounds like an engine is running. Noisy as hell!

May I shouldn't be wired two boards in parallel off of a 9v power supply?

It is probably because those Plug in AC/DC adapters have very noisy DC....
Batteries are a Pretty Clean source of DC but AC/DC adapters are very Dirty and there is a lot of Ripple.....

Try putting a Large Value Capacitor(100uF) between the Pos and 0v Power supply Rails on each of your Units and the power supply noise should become conisiderably less....


Cheers

I screwed with that thing for a few hours going through each potential problem. I finally said screw it and I'm now powering each channel off of its own 9 volt battery with an on/off switch on each channel.

I could've just wired a TRS 1/4in jack for the input and used that to break the power connection when a cable isn't connected, but I already had a hole in the enclosure for the power plug. I removed the power plug and drilled a second hole and popped in two mini toggle switches so I can turn on/off each channel as I wish.

I was going to etch the enclosure, but instead bought full sheet labels and printed the artwork on that. It actually looks pretty friggin' cool.

Thanks for your help.