OK so it gets weirder...I was messing about with the ground connections, all fine. I changed the output jack, no change. It still worked with the audio probe, and I noticed that the only difference between that and the output jack in the box was the 100n greenie cap that was attached to the probe. I soldered the cap between the output from the 3DPDT and the output jack, and hey presto, it works! WTF! What would the cap be doing that would make it start working?
So its boxed and working, however I've still got a few issues that suggest something definitely isn't quite right. The tone knob seems to be reversed, is that correct for this build? (I.e. it gets brighter when turned to the left, darker to the right).
When the treble and gain are turned up in boost mode i get a shrill high pitched noise...
In non-boost mode the gain is a lot lower than in the mudhoney demo video.
I've got another mudhoney circuit that was having the same issues so I'll try that with a cap on the output to see if it solves it. On concern I've got is that when the effect is bypassed the signal will be going through the cap...will this affect it? I guess i could put the cap between the board output and the switch input...
I've put some more pics up of what I've done in case my ramblings don't make sense...
https://plus.google.com/photos/116241861790572354815/albums/5851159051084585457Thanks
Jack