I hope I can get all these questions answered in one post... 1st... is a Shielded Signal Cable same as an Intrument Cable? (Mentioned in the instructiuns in Ampeg's SVT-6Pro's Pre-Amp Out options) 2nd... Do 1-space-rack amps exists? If so, what would be a decent/simple one to match up with an SVT-3PRO or SVT-6PRO Pre-Amp out? I'm trying to at least double my power for live shows by using an auxilary amp to either head + cab. That said, I'd like to find something with say 800-1000W at 4 Ohms 3rd... I own and SVT-3Pro and a 6Pro. Both have a Pre-Amp out options. The SVT-3Pro has (3 x 12AX7) tubes on Preamp, wheras the 6Pro has (2 x 12AX7). Anyone know what I might expect the difference to be in tone when using one over the other to power an auxiliary amp? Thanks for the help!