Why is the guitar so good at picking up mains hum or are my guitars wired wrong? I have made two kit guitars a Strat & Les Paul. A similar problem of mains hum with volume position exists on both but the LP has unique wiring so I will just concentrate on the Strat. If the volume is set around 75% it makes the guitar a perfect aerial for mains hum. At full volume there is zero pickup as shown in the picture. Both pictures are 2mV/div so there is almost 10mV of hum. :o Is it my guitar and wiring...

If I set the guitar volume to less than 95% the pedal seems to tune in to mains hum. The guitar has no hum when plugged into my Zoom 3000 so why would the Boss pedal give trouble? I bought the Boss off Ebay so I did a factory reset that went fine but setting the pedal sensitivity or range of the toe & heel switches didn't do what the manual said. It appeared to log the two positions with the right led states but pressing the switches a second time was supposed to switch it to normal mode. Is...

Hi Everyone,

I've just recently been given a Peavey Backstage Plus 35W Solid State guitar amp for nothing, and I'm currently working on it to get it back to a useable state, so, what's wrong with it?

Well, the original speaker is a no-worker but the rest of the amp seems to work fine, I verified this by plugging my pair of headphones into the headphone socket, I get normal sound through my headphones but no sound through the speaker.... :thumbsup

I've managed to find what I think should...

Hey Folks. New to this site. I repair old amps and occasionally old pedals.

Trying to understand and get this pedal working correctly.

The pedal is working but I notice the following

The red check LED does not light up. I believe it should be ON when the pedal is active. Or, maybe the older versions did not do this?

When running on a battery I see the full battery voltage at the board.
When running on a wall wort there is a 3V drop at the board which I trace back to the PS adapter socket...

Hey Everyone,
Been a while since I last contributed a new thread to the forum, anyway, thought I would start a thread about a Tube amplifier I built a few months ago, okay, so what is it? I hear you ask, it's an OTL (Output Transformerless) Tube amplifier I built using three Svetlana 6N1P medium mu twin triode tubes I bought online from Evatco, I built the amp so that I could connect my pair of Audio Technica ATH-M50X headphones to my 43 inch Blaupunkt smart TV, the TV does not have a built-in...

Hi. I built WattAmp pedal. (
It is preamp pedal with 3 transistors. It works great, but even on low gain have some loud noise.
I recorded it. Can anyone classify this noise? What should i check?

I posted the gut shots to this a while back here

The original thread for this was for the first version which was different and the schematic pics are long gone.

I got around to tracing it myself, it's slightly different than a phase 90, just some different part values and an extra resistor on the output. Enjoy.

JoyoVintagePhase.png

Hello guys. Just built UniCab from pedalPcb.
It sounds not bad with guitar. But when i tried it with bass, there was not enough low frequencies for me.
So i want to change values of some filters to just add more bass.

I hear that Size and Resonance pots are changing bass. Am i right that i have to try different values for C8 and C10?

Ok, I might intentionally have double posted this :D. I do apologise, but I think this might be of interest to more people.

I have some Qtron (+) mod questions:

1. Volume mod. I presume it would be done by adding a A10k in a standard way like this?

2. R32 mod. Is it the R32 as in the schematic of this thread ? And with what should it be replaced? I think it is already altered in this version as I read it was replacing the 100k with a 47k or lower. Am I correct?
3. Mix mod. Am I correct in...

I know the IP Police are hot on anyone posting current EH schematics but if someone has it and could PM me I'd be most appreciative.

Ok so this is a known good design to get round 24 to 25V. However how much current will it be able to draw? Will it be enough to feed a Qtron+? Or will i need to place an extra separate LT1054 in parallel (as image below)?

IMO a really good sounding distortion with a pretty good range of settings.
Heavy metal housing, good mechanical and electrical workmanship.
ONERR DST-2 Topview.jpg
ONERR DST-2 Knobs.jpg
OnerrDST-2_PCB_Componets.jpg
OnerrDST-2_PCB_SolderSide.jpg
OnerrDST-2_PotentiometerPCB.jpg
OnerrDST-2_Wiring.jpg
OnerrDST-2_PCB_Layout.JPG
ONERR DST-2 Schematic.JPG

The pedal works perfectly in 8 second mode. However, when I switch to 2 or 1/2, the effect doesn't work. When it kicks in, it basically doubles the signal overtop of the input, i.e. Just makes the sound a little warmer. There are no trails, echos, or repeats. The delay controls don't seem to change anything. The controls all work perfectly in 8 second mode however. I've recapped and swapped ICs. I get the voltages on the 4066 when sliding the selector switch. Interestingly, if I jump pins 3&4...

another blatant Klon clone, nothing new under the sun...
But in V2 they introduce 3 extra transistors? One is a run of the mill 2N3906...
Pics snapped from this video

V1 2022
centavo2022.png

V2 2024
centavo2024_02.png centavo2022_sideview.png

Hi,

I made a vero layout of an Ibanez BP10 bass compressor, based on the schematics of GGG. I checked it several times but could not find an error so far. But my build does not work. I checked the layout again and did the typical soldering troubleshooting, but no success. So I give up and will do some other build. If anybody wants to continue and do some debugging - here it is for free use.