For those of you that don't know about the delay built into this amp, it is designed to shutdown if 115V is not supplied to the amp---it will remain off for approximately 20 seconds...that delay can cause some major problems for you, especially at a live gig. For that reason, some TBers have tested removing that delay, and only good resulted. Learn more here:
Ampeg SVT VR Head requiring at least 115 volts from wall socket
For the record, I have already performed the task of jumping over this delay...