Rat whines without input

[nonost]

Hi. I've just build a RAT using the main layout. Sounds awesome but I've noticed that there's a continuous hight pitch noise when no input guitar cord is connected. Of course when the circuit it's ON, in bypass there's no noise whatsoever.

Is it supposed to do that?

Cheers!

[KT]

If i remember correctly, I've noticed that as well, don't have a rat at hand at the moment

[lasermonkey]

Yeah, it does that. I built a stereo Rat for a synth guy and I ended up using switched jacks so that any unused channels were grounded. That way it could be used in mono without the squeal from the other channel.