My Express Build with some problems

[rooster]

Eddie - Get that IEC ground out of the star ground, not a good thing, and as Mont said the filament needs another ground. Also the center tap needs its own place.

...But none of these things are making the kind of noise you are describing. The scratchy Presence pot is kinda odd. You will hear it as you turn it when you are playing gtr - but when the amp is sitting at idle, not so much. So I would focus on your Presence pot wiring. Start by replacing the 100K resistor and its connection.

On a slightly different note, not that it will fix the noise you describe, be aware that Alan Phillips of Carol Ann Amps, someone who has built at least one fantastic sounding and playing Express clone, suggests that the Presence grounding should be separate from the bus wire on the back of the other pots. I hope this helps.