Rangemaster question

[Kinski]

So, I've built the rangemaster with switchable input caps, along with a voltage inverter. Both layouts from this site.

I've build 2 of them. And both have a very faint but audible, and very annoying, high pitch whistle. Almost like a dog whistle. Its certainly not the voltage inverter, because if I remove the chip completely, I still get the whistle.

Any ideas what this could be and/or how I could fix this? Is there some sort of filtering I can do?

Here are the layouts I used for both builds:

http://tagboardeffects.blogspot.com/2012/05/rangemaster-with-switchable-input-caps.html
http://tagboardeffects.blogspot.com/2012/05/negative-voltage-inverter.html

[Kinski]

Messed around some more. Its pretty much gone when using a voodoolab pedal power. And most audible using my crappy onespot daisy chain.

[dbat69]

Kinsky
I would try a 100R resistor in series with the power.  It has worked for me when I've got a squeal.

[Kinski]

Cool. I'll try that. Thanks!

[Travis]

I think like you already discovered the power supply is often the culprit here.

If you're still getting oscillation, try socketing a small value cap between the base and collector. Start small and increase gradually until the noise disappears. If you go too high, the sound will become muffled. The best results should be somewhere between 10p-470p

It does change the sound of the Rangemaster slightly, but I personally like it if you don't take away too much high end. It can shave off just the right amount of harshness and the lower noise is a huge benefit

[Kinski]

Thanks for the help guys. Seems I was mistaken. The whistle was from the inverter IC. I started swapping ICs and found one that is dead quiet. Seems some are more noisy than others.

[dbat69]

THanks for getting back Kinski and letting us know - I will bear that in mind if I come across the same issue when using an inverter