Strange noise issue, Neovibe

[Kimster]

Hi!

I´ve recently built me a neovibe with ggg pcb and I have a really strange noise issue. I´ve tried three different adapters, but it is still there...
The unit works good and sounds good, but... after a couple of minutes (or sometimes from start) there is a whining that follows the LFO, rather high freq. Usually it´s increasing during 2-3 sec and then is there for a couple of minutes, then it suddenly disappears and is gone for a couple of minutes, then it comes back again... The neovibe works fine all the time except for the noise.
Anybody have an idea? Could it be a bad capacitor that works occasionally? The noise is there both in vib and chorus mode.

// Kim

[R.G.]

Either you have an intermittent solder joint or wire, perhaps an intermittent contact on a jack or switch,
or
you have an intermittent heating problem on something, perhaps the voltage regulator, perhaps a cap,
or
you have an intermittent self-oscillation problem.

If it were mine, I would put an oscilloscope on it and see where in the circuit it starts. Failing that, I would resolder all the PCB joints and feel for anything getting hot on the board. If that didn't help, I'd start reading DC voltages with no signal.

[Kimster]

Ok, I´ll try it in that order! Wish me luck and thank you R.G. both for making the layout for this and help me!

// Kim

[Kimster]

It was the voltage regulator! Thanks again!

// Kim