Valhalla Distortion issues

[ammendes]

Hello, I'm new to the forum.
Built a couple of pedals before (a delay, a noise gate and a compressor. No issues there).
My knowledge on circuitry is not the best compared to the craziness I read around this forum, so bear with me.

I built a Valhalla Distortion and I'm getting the famous squeaking.

I went through every component, and found that all of them are correct and correctly placed on the board.

When using the POWER OUT, with the pedal off there is no sound, as expected. When I turn it on I get a big squeak that can be played around using the EQ and Gain knobs on the pedal. I can make the squeal go away by lowering everything. I can hear my guitar with distortion, but very muddy and far away.

When using the normal output, the bypass sound is perfect, no buzzes. When I turn the pedal on it goes into squeak and hum mode.

Funny fact, when I have it on, just touching the pots on the pedal or the ones on my guitar, and also touching the strings, changes the frequency of the noise. Also, when I throw a chord on the guitar, the squeak kind of goes away. It squeaks when the guitar is idle most of all.

I've read around threads, and saw a fix involving adding a buffer pedal before the valhalla. I don't have a boss pedal. Tried adding in a noise gate I got from Musikding, that pretty much clears the sound totally. Also saw people introducing a second board on the pedal itself, but the reason for that goes beyond my knowledge.

Can I get some help here please? How should I go about troubleshooting this?

Thanks!

Here's some pics of what I have. I use a 3d printed enclosure, and I removed everything from there except the DC input to take the pics. Happy to take more pictures of any detail you wish

 

[ammendes]

The quality of the parts. Disk ceramic caps. Stamped metal pin IC sockets. An out of date circuit board. 1/4W resistors where 1/8W would be a better fit. I don't buy from Musikding, but I have read many stories in this troubleshooting forum from people who have. It is not uncommon for the parts kit to be incorrect or incomplete. Those are not high-quality jacks. Look at how a 1/4" plug engages in the jack and tell us if it fits properly. Lower quality jacks have the wrong shape or dimensions and the plug does not snap in completely. I bought some jacks at the local electronics store and I had to insert a plug into every one to see if the engagement was good. I rejected about 20% of the ones I checked. They look a lot like yours.

It's the only EU based seller I know

Their service is horrible for sure.

The jacks snap and they fit the socket properly.

Now, I was looking at the board on the pedal PCB catalog and it looks just like the one I have. Would you mind telling me what's different between the V1 and the V2?

 

[Robert]

You have the current version of the PCB.

 

[ammendes]

Update on the issue.
After rewiring the pedal (pix below) I did some rudimentary tests:

I used the normal output of the pedal for everything. Volume knob always at 100%, Deep and Presence at 50%. So, the values I'm refering to next are the Treble, Mid, Bass and Gain, by this order.
---------------------------------------
0 0 100% 0 - no squeal

0 0 100% 100% - no squeal

0 100% 100% 100% - squeals, pitch lowers when I touch Bass or Gain knobs, also a bit when touching the Deep

100% 100% 100% 100% - squeals, higher pitch than before, therefore increasing Treble ups the pitch. Now when I touch the Gain knob instead of the pitch changing, the sound kinds of brakes intermittently at very high frequency. Also, when I touch the Volume or Medium, the squeal just becomes more present.

100% 0 100% 100% - squeals as before but with higher pitch, therefore increasing Mids lowers the pitch.
----------------------------
Now, I plugged my old Zoom G2.1u before the pedal and have it on bypass. It squeals. When I turn the noise gate on, there is a threshold where the squeal almost completely goes away and I'm left with guitar sound and lots of hum when guitar is idle.

Then I went to get a scientific control and plugged the Zoom only, without the Valhalla. Turns out, that if I use distortion with the Zoom and no noise gate, I also get a squeal, which rules out the pedal being the culprit. I guess it just amplifies the signal resulting in a squeal, just like any Gain pedal would.

Then I noticed something in my amp. It's an old Roland Cube 15W, the version without the effects (only has clean and distortion channels). When the volume knobs are at 0, I still hear the guitar and also some abnormal hum. Could the amp be the culprit?

 

[music6000]

The plastic enclosure is the main issue here as Chuck noted earlier.
It really needs to be in a metal enclosure!

 

[ammendes]

The plastic enclosure is the main issue here as Chuck noted earlier.
It really needs to be in a metal enclosure!

Is there any clever way to ground the plastic box?

 

[Erik S]

Is there any clever way to ground the plastic box?

See Chuck's recommendations on page 1.

Also check out @DailyDovetails build reports page.

 

[DailyDovetails]

See Chuck's recommendations on page 1.

Also check out @DailyDovetails build reports page.

You can get a passably low level of hum with lower gain and volume. I had been pretty happy with even the unshielded pedals until I got into playing some metal stuff recently. You can get a passably quiet enclosure with copper tape shielding and shielded input and output wires. The reason I have primarily stopped doing the 3D printed enclosures is that by the time I design, print and shield the enclosure the cost is only 1-2$ less than the metal enclosures and the time spent is much more.

That being said if you enjoy 3d printing and modeling I encourage you to continue doing it as you will learn a lot throughout the process.

 

[ammendes]

You can get a passably low level of hum with lower gain and volume. I had been pretty happy with even the unshielded pedals until I got into playing some metal stuff recently. You can get a passably quiet enclosure with copper tape shielding and shielded input and output wires. The reason I have primarily stopped doing the 3D printed enclosures is that by the time I design, print and shield the enclosure the cost is only 1-2$ less than the metal enclosures and the time spent is much more.

That being said if you enjoy 3d printing and modeling I encourage you to continue doing it as you will learn a lot throughout the process.

I do a lot of 3d Printing but I guess you're right.
I play mostly metal, high gain, so it's always a battle against hums and noises.

Thanks for the advice. For now I've settled with settings that dont squeal but still put out a lot of power.
I was hoping my noise gate pedal would do something but it doesn't, something's probably wrong with that one as well.

Will try proper enclosures in the future to see where that goes.

 

[DailyDovetails]

I do a lot of 3d Printing but I guess you're right.
I play mostly metal, high gain, so it's always a battle against hums and noises.

Thanks for the advice. For now I've settled with settings that dont squeal but still put out a lot of power.
I was hoping my noise gate pedal would do something but it doesn't, something's probably wrong with that one as well.

Will try proper enclosures in the future to see where that goes.

You can print lots of pedal parts and templates that you might find helpful. I have been thinking of doing faceplates recently. Nearly every build I do has some 3d printing involved.

 

[ammendes]

Just wanted to give you a big thank you for all the replies and a briefing on how this ended up.

I believe the squeal is more related to the incoming signal than anything else. Afterall, any high gain like this pedal allows gives me the squeal I complained about. It's not specific to this pedal. I found some settings that produce the sound I'm looking for, and those don't give a squeal.

About the enclosure shielding and grounding, I went on a tried covering the inside of the plastic enclosure with aluminium foil and glue. I made sure to get continuity between the top and bottom of the enclosure. Pics below.

Overall I'm satisfied.

It was also nice to join this forum. Lots of knowledge and nice people.

Best