Nik turned me on to this great mod.  I replaced the standard volume pot with a 1M push/pull pot with two solder lugs:



I borrowed Hoffman's pic because I bought the pot from him.   If you need parts quick, he's great.

The 15k resistor that's soldered to the back of the original pot is lifted and soldered to one lug of the new pot.  The 3 upper lugs are connected as per stock.   However, an additional ground wire jumps the pot's ground to the second solder lug:



In position 1, the amp is very clean and has less volume.  In position 2, it's big and fat with extra gain.

I've sold off a lot of old gear recently, and am considering what to work on next.  My current stock:

Custom Tele (view it at http://www.reranch.com/reranch/viewtopic.php?t=23152&highlight=snakecharmer)
Custom Strat
'90 Les Paul Studio
Ceriatone BF Vibro Champ w/1 Copperhead, 1 Delta Demon
Laney Lionheart LT5-112 w/Vox Wharfedale 112 extension cabinet
Various pedals, etc. etc.

I wanted to pass this tip along for the Vibro Champ owners.  At Nik's suggestion, I tried this mod and adds a lot of gain to the amp.  Lift the 15k resistor from the volume pot (clip the wire or desolder the connection).  I replaced the pot with a push-pull pot so that I can use the cleaner, low-gain setting with the resistor in place, or pull the pot to the B position to give me higher gain and a lot of nice breakup.

I play my Ceriatone Vibro Champ through one Eminence Copperhead and one Delta Demon speaker in a 210 cabinet.  My Strat never sounded so good...