Deluxe Reverb servicing, I need some help.


TDPRI Member
Nov 10, 2013
The only issue: the low E string, played open, is a little farty, not horrible, but saggy and flabby. It is fine on volume knob setting from 1 to 6, flabs out from 6 to 8, then tightens back up at 8-10. I almost never play past 7, even outdoors, so cranking it to 9 or 10 is not a good fix.

I may try switching out the first 16uF filter cap in the doghouse with a bigger one, JJ makes a 30uF-500V one that will fit under the hood. Suggestions welcome.
I’ve seen people just add another 10-16uF cap in parallel there.

You can also try making the coupling caps smaller, that can help reduce bass. I don’t have the schematic in front of me but it’s common to cut the coupling caps in half (ie a 0.1uF to 0.047uF or even smaller).

Another way to reduce bass is to reduce the cathode bypass cap on the second gain stage (ie the second half of your preamp tube). 25uF is commonly the factory build; 1-2uF, etc below 5uF can make an audible change.

So if you have spare parts you can tweak stuff. Sorry I don’t have a schematic in front of me.