SOLVED Abyss and other chorus pedal twitching sound

[Grazza]

Hi all,

I finished an Abyss yesterday and everything works and the pedal sounds great apart from this digital kind of twitching sound, almost in the background of the effect. It doesnt overpower the effect at all but it is definitely there. Also, probably not coincidentally I built another chorus pedal a couple of months ago and a couple of weeks ago it started making a very similar twitching sound when the pedal is on too. Hard to describe the sound. It is based on a boss CE - 2 i think, called a BBE Lich King (https://www.diyguitarpedals.com.au/shop/index.php?main_page=product_info&cPath=35&products_id=601) Really great sounding pedal, both are in fact, and I'd love to get them working properly but I have no idea where to start with this. I'm not bad at putting them together these days but not great at harder troubleshooting.

Gut shots below if it helps. Any help would be greatly appreciated. The green one is the abyss and the one on the left is the Lich King.

 

[Grazza]

I think it is a DBE Lich King, sorry.

 

[Erik S]

Get a recording of the sound if you can. Without hearing it, cell phone interference is the first thing that comes to mind.

 

[Grazza]

I'm not sure that I have the capacity to make a recording, will give it a go. I don't always have my cell phone with me, however I have just moved a router to that room, will try them in another room too.

 

[jwin615]

I'd try different/isolated supplies or a battery as well.
Is it always present or only when playing?

 

[Grazza]

OK, took both pedals down to the computer to try to record the noise and I couldnt hear it. The pedalboard on my computer has a few drives on it, into an interface and the same power supply as the one I'm running for my little effects loop pedalboard that these two pedals sat on. Mosky ISO 10, not the most expensive supply but has proved to be really quiet so far. There are 2 computers and a router in the study, and just a router and TV where the amp is. I have recently added a UAFX DELVERB which is bluetooth connectable also, I will explore further but I dont think there is anything wrong with the pedals, I left the backs off the enclosures too if that makes them more susceptable to noise. there may have been a faint whining from the abyss, was a bit hard to tell if it was the effect or interference.

 

[Grazza]

will test battery power too.

 

[Grazza]

It's not the UA delverb, I don't have them means to test with a battery as power at the moment, I didn't build either effect to run off battery. The pedals usually sit on a small board on top of the amp plugged into the effects loop with the power supply under the board, I'm assuming any of those transformers could cause interference. Interesting that it doesn't do it with the other mod and delay pedals on that board.

 

[jwin615]

It's not the UA delverb, I don't have them means to test with a battery as power at the moment, I didn't build either effect to run off battery. The pedals usually sit on a small board on top of the amp plugged into the effects loop with the power supply under the board, I'm assuming any of those transformers could cause interference. Interesting that it doesn't do it with the other mod and delay pedals on that board.

Next tayda order, grab a barrel jack and a few battery clips. Wire one to the barrel jack. Another to Dupont wire(for breadboard use)
Good to have for troubleshooting and also initial bench testing. I'd rather accidentally short a 9v than an AC adapter.
But it definitely sounds like there's something interfering in the room.
The first thing is change is power. Everything else the same(room, pedal chain, etc), put the pedals on separate power. It could be a different pedal adding noise on the ground and it's leaking in. Could be a lot of things. But only change 1 thing at a time to narrow it down. Remove 1 pedal from the board at a time. Turn 1 light of at a time (LED and CFLs are very noisy in term or RFI). Etc.
Take into consideration that you may have a transmit and receive issue and may need to address both the symptom and the cause once you determine the cause. And don't take anything for granted. IIRC @jimilee and @bean had similar (to each other) noise issues a few years back at finally determined that it was the tyada blue LED they both used in different builds.

Could you possibly just make a phone recording? Turn your guitar down and you amp up and grab a 5 second clip?
Hope this helps and happy hunting.

 

[Grazza]

Update:
Turns out there was another mod pedal, a Dr. Scientist Cosmichorus two pedals back in the line that was causing the noise in both the abyss and another chorus/Vib pedal. I moved it futher down the line past those pedals and the noise has stopped. Who woulda thought! Probably you guys, but I've learnt something new! I really appreciate everyones help and suggestions!
Thanks.

 

[jwin615]

Update:
Turns out there was another mod pedal, a Dr. Scientist Cosmichorus two pedals back in the line that was causing the noise in both the abyss and another chorus/Vib pedal. I moved it futher down the line past those pedals and the noise has stopped. Who woulda thought! Probably you guys, but I've learnt something new! I really appreciate everyones help and suggestions!
Thanks.

It's probably interplay between charge pumps. Isolated power should fix it. The mosky/Moorer/etc pedal supplies aren't isolated.
Swapping to another charge pump of a different frequency may help as well.
Glad you got it sorted.

 

[Grazza]

I didn't realise there were charge pumps at different frequencies, another thing I've learned today. I will upgrade the power supplies eventually, I just started building pedals and they multiplied so fast I couldn't keep up and needed power quick. I must admit for $60AUD I wasn't expecting much but they have exceeded expectations by far, and have been issue free til now. Thanks again

 

[spi]

Good you found the cause. I think you can mark troubleshooting threads as solved.