So why doesn't my presence control do anything?

greengriff · Post by **greengriff** » Thu Jul 23, 2020 10:30 am

First post. Looking forward to interacting with you all. Amp is a stock '77 2103. It sounds stellar - far more 3 dimensional and 'alive' than my 2203x through any one of my cabs. The presence circuit appears to be wired correctly (although I didn't lift the board) to the 4ohm tap, just like the reissue. Presence pot measures 4.1k in circuit (I presume it's a 5k pot?) and sweeps cleanly down to 0k. However the presence knob does absolutely nothing. The amp is very quiet in terms of background noise and hiss, but even with all the controls on 10, turning the presence knob makes no discernible difference to the tone of what little noise and hiss there is. I'm really curious as to why that might be, and so would welcome any input.