Valhalla issue

[PKRPedals]

I have noticed a couple quirky things with my Valhalla since building it. It has the same squeal/oscillation that my pineapple has when the gain is up around 2 oclock. Also when turning down the eq section all the way, it kills the volume. I run my cable from the power amp out to the front of the amp, it actually sounds better to me this way, and the pedal acts like a mute when you switch it off, but this my be normal for it to do that. Just thought I would bring it up. I have used all my guitars with this pedal and the pineapple and they all cause the squeal. I thought my Les Paul was different but turns out it does it to. These are the only 2 pedals that I have this issue with and I can't seem to figure it out. I reran my cables in the pineapple with shielded cables and that may have helped a bit, but it still has the squeal. My Thermionic and Thermionic Deluxe don't have the squeal. Now with all that said, these pedals sound amazing but I have to roll off my volume just a bit to make the squeal go away. I can deal with it but would rather it work properly. Any ideas?

 

[familybezerker]

I solved my oscillation problem! It was my switching power supply. Using a non-switching power supply fixed it.

I got the idea from one of bajamans earlier posts on FSB where he said his power supply whined.

I have no whine when the guitar is plugged in. If there is no input into the pedal, it will while above 60% gain but putting the Valhalla in front of a buffer pedal solves this.

I shielded the input and output wires but have no way of knowing without unsoldering what effect this had on the final result.

Now - since I have an real VH4 pedal, when comparing side by side they are very close. The character and sound is all there.
The real one is a bit more crisp - more hifi. I wonder if this is due to the Nichicon and Wima caps in the original plus they have an OPA2134 in IC1 and I have a TL072. I may try upgrading these components to see if it brings it close. The huge yellow Wima cap in the original may have to be bent in some way to fit inside the enclosure.

[[I ordered this Valhalla kit from Musikding. I realized after the fact that one difference between their Valhalla kit and their Benzin VH4 kit is that the Benzin VH4 kit includes the OPA2134. However Valhalla kit BOM has the correct C25k pots but I received B25k with it.]

 

[Chuck D. Bones]

Some switching power supplies are very noisy. Some have stability issues.

As for the sonic differences, it could be down to component tolerances or the opamps. If you have film caps, you probably won't hear the diff between brands. If you replace ceramic with film, that you will probably hear.