As Chris mentioned, removing the 50K
 pot will increase overall amp gain. I also
 found that it made the amp cleaner,
 which would make sense - a 50K load
 to ground on a 12AX7 output is pretty
 heavy loading. If you can find a 50K
 pot with an SPST switch, the killer
 mod is to make the tremolo switchable
 at the pot (the switch disconnects the
 lead at the 'top' of the pot going to the
 220K/.1 uF cap junction, and takes the
 tremolo circuitry completely out of the
 picture). I recently did this to a '66
 Super, with very good results.
 
Ray Ivers
R.A.G.E. Electronics

 
http://www.teleport.com/~vibroman/parts/tech14.html
 
Get the Alpha 50k RA pot, get the switch, put the switch on the pot, replace your tremolo intensity control with the new pot & switch, wire up the switch so that the lead that goes to the 220k summing resistor just before the pi gets disconnected when you turn it all the way off.
 
Leave a couple of those pots for me! Now, what exactly is the effect of disconnecting vibrato? More gain?
 
Shea