gain control in express amp

[phsyconoodler]

Anyway,can't use the type 4 with this layout,but I know a guy who added a pot in place of the voltage divider to v2 and says it's awesome.He also added a pot between the last stage and the PI as a master volume(pre-PI) and it also had great results.
Yes,I know it changes the circuit into something else,but a couple twists of the knobs and you are back to the stock circuit.
It's all about versatility.