fetzer valve help...scratchy noise from trimpot?

[Night0wl]

Hi all,

I just built a Fetzer valve FET booster from runoffgroove.com and it actually works but.... I trimmed the voltage to 4.5 and the boost is fine but there is a scratchy noise coming and going constantly. When the trimpot is touched it makes that noise and the signal is lost. If I turn the trim slightly I hear a pop and the signal is gone. Then I turn it back and I get sound with the scratchy sound aswell. The only time the scratchy sound goes away is when the trim is backed off but the signal ends up softer than the bypass.

Any ideas?

Thanks,
Shane

[Night0wl]

*bump*

can anyone help me with this?

[vanhansen]

Sounds like a bad trimpot to me or a bad solder joint somewhere in that area.  Double-check all the solder joints and if that doesn't stop it, change out the trimpot.

[Night0wl]

Thanks Erik I will try that

Cheers,
Shane