Switching preamps in and out

Hey, Wolfie, don't you think that is a bit of a bold statement, considering that you don't even know what components are being used, what the designs of their input stages are, what effect a brief overvoltage might have on their long-term reliability, what their grounding configuration is, whether or not they provide a ground lift switch, whether or not he's using cheater plugs on any of his components, whether or not any of his components have two-prong power plugs, and whether the connections are RCA or XLR?

Note also that I referred to a "CONCEIVABLY damaging voltage."

Have you ever connected the probe of an oscilloscope to a low or zero voltage circuit point on a piece of equipment, without connecting its ground lead, and looked at the voltage waveform that is displayed on the scope under that condition?

Regards,
-- Al

I completely agree with Al, (as usual). My preamp, (Modwright LS100) and my amp, (Sanders ESL) BOTH MUST be turned off and the amp allowed to drain off.

If I try to plug or unplug the RCA cable from preamp to amp with either on, it makes a gut wrenching, heart stopping, horrible noise and will usually blow the fuses in the amp.

IMHO, always turn off any component(s) that you are changing cables to.

Turn the amp off before switching.
And I agree with Elizabeth on this one. You really need to take time to listen to each pre to fully understand what you are hearing. Too often the piece that sounds best in short term comparisons don't hold up as better over time. They just stand out during the test. At least that's my experience.
If you do make the hot swaps, please post the results.

Elizabeth got it right. I find it difficult to switch from albums to CD's (and vice versa) in one listening session. The first source always sounds better than the second one.