Buzz/Hum with Catalinbread Katzenkönig

[Philtre]

Hi, new to the forum and I've successfully built a few pedals from the layouts here. But today I have a problem...

I've built the Catalinbread Katzenkönig from this layout - http://tagboardeffects.blogspot.co.uk/2017/05/catalinbread-katzenkonig.html. It works, and the pedal controls do what they are supposed to do, but there is a loud buzz/hum from the output even if nothing is connected to the input. Done all the usual checks for solder joints and even tried swapping out some of the caps. The noise makes the pedal unusable. Would appreciate some help in where to focus my attention.

Phil

[induction]

Could be power supply noise. What are you using for power? This type of circuit often only behaves well with a battery or a regulated adapter.

[Philtre]

Just a 9v battery. Also with a regulated supply. The buzz is the same sound as when you put your finger on the end of an input jack.

[induction]

It's worth a try, but if it hums with a battery then it's probably something else.

I'd try
1. looking for solder bridges and cold solder joints, especially on ground connections
2. use an audio probe to trace the signal path and figure out where the hum first shows up.

[Travis]

Did you ground the enclosure? I have this problem if the enclosure is not properly grounded, it will buzz even in bypass

[Philtre]

I'm testing it outside of an enclosure. I have it hooked up to some pots and sockets.

If the volume control on the effect is all the way down there is no buzz which makes me suspect it's something in the circuit.

[Philtre]

Actually, Travis, I think you may be right. I took an enclosure, soldered a wire to it and connected it to ground on the circuit, then covered up as much of the input wires and vero as I could. This mostly eliminated the buzz. This must be a high gain thing on the input.