Signal leaking through power supply?

[Gaz]

First, here's the schematic of the amp that's annoying the crap out of me (the channel switching is a relay):

[IMG864]http://i56.tinypic.com/73ecf5.png[/img]

While testing this new build, I noticed a faint distortion in the Normal channel. I assumed that the Boost channel was somehow leaking into the Normal channel. I stole the switching scheme directly from the Budda Superdrive, and was suspicious that something else might be going on.

[IMG1224]http://i51.tinypic.com/33js7jl.jpg[/img]


I was able to silence the bleed by grounding the grid of the second "Boost" stage, but didn't understand exactly how the distorted signal was still getting to the grid of the following stage.

I found that the amp was leaking signal to the third stage (driving the CF), even with it's grid completely disconnected, which leads me to believe that's it's coming through via the power supply. I really have no idea how to trouble shoot this, and would appreciate any theory behind why this is happening.

I'm also curious if this is normal to a certain extent, and if I need to simply add an additional relay to mute the grid of the second stage while not in use.

Thank, and sorry for the looooooong post.

[Structo]

That's strange.

Do you have a scope?

The Dumble Overdrive Special grounds the grid of the OD channel when in clean mode.

[Andy Le Blanc]

scheme looks good, how was the ground implemented as you dressed the amp?