Bottom line, the fewer variables in your audition, the better. If you can't audition it in your own home with your own preamp, speakers, and other peripherals in your own room, you're not going to be able to draw a reliable conclusion about how it sounds versus your existing amp.
Bringing your preamp to his place will be better than listening to it with his gear, but it's still not enough info to make a solid decision about buying it. Not when we're in this price range, anyway.
Bringing your preamp to his place will be better than listening to it with his gear, but it's still not enough info to make a solid decision about buying it. Not when we're in this price range, anyway.