BYOC Spring Reverb weird noise

[rockybottom16]

I just finished a BYOC "spring reverb" kit yesterday, and it sounded wonderful. Today, it has a faint high-pitched whine or whistle that gets louder as you turn up the reverb level. Maybe the noise was there yesterday and I didn't notice it because I was excited about the new build. But I really think I would have noticed it. Who knows. I've built amps, but this is my first pedal build; and I don't even know where to start looking for the cause of this noise. It's a shame, since the pedal sounds glorious otherwise. Has anyone else encountered this problem with one of these pedals?

 

[Peegoo]

@rockybottom16

"Chopstick" it. This is a basic troubleshooting process that can help find problems in audio circuits.

Here's how.

Open it up and plug it in. Replicate the undesirable sound and while it's doing that, go through the entire circuit, gently tapping on each wire and component with a wooden chopstick or other small non-conductive tool. Include the pots and jacks. You are checking if there's a microphonic component in the circuit that may be oscillating.

If there's a microphonic component, it will bark at you when you poke at it.

 

[rockybottom16]

That is actually the first thing I tried last night. I poked, prodded, and tapped on everything; but nothing seems microphonic. BYOC doesn't seem to offer any tech support. They do have a forum, but after multiple tries it still won't let me register. So at this point I can't make any inquiries there. I'm hoping not to end up with an 80 dollar door stop.

 

[Peegoo]

@rockybottom16

Two other things to check:

-Proper polarity on diodes and polarized caps. If these are installed backwards, it can cause beeps and squeaks

-Correct wiring on control pots. Double check your work against the diagram. Improper control routing can cause issues like this. Get a second set of eyeballs on it because it is too dang easy to simply 'not see' a mistake you made. It has happened to me a lot.

 

[rockybottom16]

The pots are hard mounted to the pcb, so no wiring there. The odd thing is that both controls work as they should, and the reverb sounds really nice. There are no beeps or squeaks, just a constant high pitched whine that goes up in volume as the reverb level knob is turned. It's not terribly loud, but it is loud enough to be very annoying. I did notice that if I rap on the board on one side, I hear a very faint reverberation sound. Another thing is when I switch the unit on with the footswitch, I hear a very faint static sound. I will start reflowing the joints I can get to and the switch terminals later today.

 

[rockybottom16]

I seem to have found an answer. I tried two different 500mA power supplies, and they were both noisy. But when I tried a 1000mA supply, the noise was gone. This being the case, I'll bet this pedal would eat up some batteries if I tried to use them. I don't know for sure if the pedal really needs all that current, or if the other supplies I tried are just noisy. I may never know. But it works now and is pretty quiet, so I'm happy.