Does one NEED multiple amps?

One amp for each rig and one backup- that's one right?

I posted that quote from Terry Cain (whose speakers I own). Oddly, at the time he posted that humorous blurb on AA, I owned only one amp thought he was joking (which he half was). Now, I own four or five depending on the week.

My experiences have been that amplification differences tend to be much more readily apparent in the low power/high-efficiency realm than higher powered setups.

Part of my buying spree was due to the fact that I had just made the jump to a low power/high-efficiency system. The odds of buying just one amp and knowing for a fact that it is absolutely the best sound for your own personal preferences in a new system is a long shot at best.

Who can which which design is right for their system without ever hearing a few of them? - Push-pull, SET, SEP, Parallel PP, cap-couple, transformer-coupled, cathode follower, Lofton-White, etc.

Who can say which output tube - 45, 300B, 2A3, 6C33C-B, EL34, EL84, 211, 845, KT-66, KT-88, KT-90, 6550, etc. is the right one without ever hearing them in their own system?

What about the influence of input and driver tubes?

Informed decisions require in-home experience with multiple designs and tube types before settling on something permanently. Now that I've done that, I'm downsizing to just two (or three amps) this month - Art Audio PX-25, Welborne DRD 300B monoblocks, and a DIY fully differential PP amp. Each has it's own special merits depending on the material being played.

Also, I'm not sure any single amp can do it all best - the PX-25 comes damn closests out of the 15 or so amps I've tried the last few years, but even then, a really good PP design is better on large orchestral, hard rock, or percussion heavy music. And the 300B's do ambient/spatial information in a way that is hard to match. Take choral or classical music performed in a large cathedral - nothin like the 300B for that spooky ambient hall sound.

One amp, 3 cd sources of varying flavor, 2 armwands with different flavored cartridges mounted. I suffer from Terry's affliction, but am happier varying the source than the amp to solve it.

I would say there is no such thing...no amp is perfect. You choose which set of imperfections you can live with.
And trust me when I tell you that Terry owns "quality" amps. He has more quality amps than I have fingers and toes! That's one of the reasons it's always fun to go to his place!
Steve

I agree with darkmoebius that amp flavors are most distinguishable in the low power/high efficiency realm. Have tried 2A3, EL34, 6550, KT88 and 845 tube amps. The EL 34 and 845 amps are keepers, my 34 amp does subtlety and the 845 does excitement, spaciousness. I am now looking at 300B amps for another flavor. I do not forsee myself getting rid of either the 34 or 845 amp anytime soon even if I get a 300B amp. I actually regret selling my 2A3 and another EL34 based amp as each did some things my present amps don't, still, we have to be somewhat sane here. If I had the money I would have 5 or 6 different systems, one for every mood. Now to the question of whether we need all of this, no way Jose. On the other hand, making an analogy to food, why should we settle for a one course meal when we can have a feast of many.