Foxx Tone Machine - Ringing Noise

[Minimallamb]

Hi there, I'm having trouble with a Foxx Tone Machine built from the layout on this site (http://tagboardeffects.blogspot.co.uk/2012/03/foxx-tone-machine.html)

It sounds just like it should except theres is a high pitched ringing noise constantly on, even when there is no guitar plugged in. I can't tell if the gain knob effects it but the tone a level pots do. It becomes harsher and higher pitched with all pots on full and is present in both the normal and octave up modes. Has anyone had any problems like this on a pedal before, I've built around 20 now but have never come across this sort of sound.

I'd be so so grateful if someone could help me out with this as i LOVE how the pedal sounds but the ringing sound just makes it unusable.

Im using 2N5088s


Q1
C-2.08
B-0.71
E-0.14

Q2
C-7.58
B-2.08
E-1.49

Q3
C-6.83
B-0.81
E-0.23

Q4
C-7.30
B-0.82
E-0.27

[Travis]

Welcome to the site! Nice looking build overall, I like that dark stripboard

I see many potential solder bridges on the bottom of the board. I’m not sure what’s going on with the black stuff at the bottom corner near the green and yellow wires

I would first use a small file or knife to clear all solder from between the strips. Those could create a feedback loop causing oscillation

[Minimallamb]

Ahh thanks so much, I didn't think to try running a knife down them

I got in a bit of  mess when I'd soldered in most of the components and then realised that I had some cuts in the wrong place


I'll try and tidy it up a bit now and post the results

[Travis]

You’re welcome. Most of us here will clean the underside of the board to some degree on every build. It’s such a common problem to have a tiny spec of solder kill the whole board, it’s easier to just clean it every time

Your soldering looks good overall. The Tone Machine is a fantastic pedal

[Minimallamb]

I've cleaned it up a bit with some IPA, ran a scalpel blade along the tracks and tidied up some of the blubber bits of solder but still ono luck

[Addy Bart]

Are you using a trustworthy power supply? Nearly everything I make benefits from a low value resistor (47R usually works well) between the DC jack and board. (I use a cheap 1spot).

Build looks good and I like that dark brown vero too. Hope you can figure out what the problem is!