There is a Variac in there to prevent the Marshall from over-heating (which it has in the past). It doesn't do much to the sound but helps w/ "mechanical failures"!
The pedals on the floor are a Teese RMC3 wah-wah, an MXR Phase
90 and a Pharao Boost (since replaced by an MXR EQ).
On top of the rack is an MXR dual 10-band EQ which I use on/off to shape the signal before it enters the rack.
Not pictured is a CAE RS-10 which controls the 4x4 and G-Force.