Marshall Super Bass

[dperry]

Hi guys,

First time poster here.

I have built the Marshall Super Bass as shown here http://tagboardeffects.blogspot.com/2018/10/marshall-1992-super-bass.html

The problem i am having is that the treble control exhibits weird behaviour on both channels.

When i turn it fully (to 10) it does seem to work as a treble control, but it also cuts the volume quite significantly.  Turning it to zero cuts the treble and boost the volume massively.

I've checked all my wiring and it looks good.  Any suggestion of where to start with debugging?