Need help with tone control on Expandora clone

Winny_Pooh

So I've built it and it sounds great but the tone control isn't doing anything.

I've checked the pot with a multimeter and it's fine as well as the connections from and to all the components in this part of the circuit.

Tone control part is to the left of the center chip, see the 3n3 cap above the two diodes. That's c12

roberty

Have you made an audio probe? They are easy to make. You can find out exactly where the signal is or isn't going. I put it off for ages, but it only took a few minutes to put together in the end

http://diy-fever.com/misc/audio-probe/

roberty

Here's mine, I borrow the ground from my circuit tester since it supplies power and input. Plug the probe jack into your amp and then you can touch the hot wire to various places on the PCB to hear what the signal is doing there

Winny_Pooh

@roberty cheers seems a logical step

Winny_Pooh

Made the circuit tester and eliminated any bad soldering. Frustrating. The only thing left was the 3n3 cap so took a chance and put in a 4.7nf I had and voila, it was a faulty cap FFS! 

Sounds great now, the bass switch may have the same cap issue which I may go back to one day. For now enjoying it alot. Brilliant used with just one clipping stage and nice and clear on a neck pickup too.