Hey, I'm no expert. If you see errors please let me know.  If you do these mods, it's entirely at YOUR own risk.

If you don't know what your doing... Don't do it.  It could kill you!!

The circuit at right is a schematic of the typical tone control with mid control.  I lifted the ground to the mid pot and added the components and the switch.  If you don't have a mid control.  Lift the grounded end of the resistor going to ground off the bass pot and do the same thing.

I did this mod to my Super Reverb. The switch I use is a jfet controlled by footswitch.. You can put a panel switch in if you like.

I did this mod to my 5F6A Bassman.  I only have one input now.

I used the first half of the gain stage as a pre/preamp.  You can use it to push the second stage a bit harder or trim back for pickups that are really too hot.  This mod is not a distortion mod.  When the first volume pot is at "0" you get about what you would get if this mod was bypassed.

Check out the second stage.  I changed the plate resistor to a 220k.  I like the overall end result.  IT"S ABOUT TONE.