Can I plug a bass or guitar preamp into the VB-101?
The sound of a bass or guitar amp is generally crafted with a preamp and a power amp, especially in the case of a tube amp. A head amplifier already contains a preamp and a power amp. The most common way to record an amplifier is to plug the Output of the power amp or the Output of the head amp into the "Amp" input of the VB-101.
Besides, the VB-101 includes a XLR symetrical or asymetrical line Input, into which you can connect a bass or guitar preamp. That way, you can take advantage of the VB-101 simulation without having to add a power amp to your preamp.