What is your experience with amp power?

My personal preference and priority is for lively sound at modest volume levels. This is more commonly achieved with tube amps than solid state.  My favorite tube types happen to be quite low in output, and I prefer amps that don’t rely on many tubes operating in parallel—fewer tubes sound more pure and clear to me.  This does mean I have to make do with lower power, but this is a minor compromise because the power I get from my amps is “sufficient” (Rolls Royce used to stay away from the numbers game by refusing to give a horsepower rating for their motors, and instead, they said its output was “sufficient”).  With my 99 db/w speakers, I get by with 6.5 watts per channel from a parallel single-ended 2a3 amp and 5.5 watts per channel from a pushpull 349 amp (my favorite amp).

The "high power" tube amp that I like a lot is the Synthesis A100 (rated at 100 wpc).  That amp runs tubes of my liking-KT66 in pushpull-so it is sort of the exception to what I generally like and dislike.  If someone truly needs much more power, even though I am a tube fan, I would suggest looking at solid state because, to me, many high powered tube amps sound hard and brittle (some call it "glare").  These days, solid state does not sound harsh or "grainy" (terms commonly applied to solid state in the past); to me they sound a touch lifeless at modest listening levels and are not quite as engaging (one's mind tends to wander instead of being pulled into the music).  There is no doubt that solid state can deliver very tight and punchy bass, but overall, it is still tubes for me.  I also don't have a particular preference for tube topology--I like some pushpull amps, single ended triode amps and output transformerless amps.

It was a while ago that I auditioned two Rowland amps of very similar design.  One was rated at 50 wpc, the other something like 200 wpc.  The primary difference was the number of transistors per channel.  Both were playing the same somewhat difficult to drive panel speakers (either Maggies or Acoustats, I don't recall) at relatively modest levels.  I actually preferred the lower powered amp, and so did the owner of the store.  There might be a sound quality compromise to using more output devices to achieve higher power.

bigkidz,

As I explained above, I had the same experience with a lower-powered and higher-powered Rowland amp.  I generally tend to like the sound of lower-powered amps.  I tend to like tube amps that run the likes of 6L6 or KT66 more than I do amps running KT88 or KT150, for example, and when speakers are sufficiently efficient, I like single ended 45 and 2a3 amps.  Even in the solid sate realm, some of the lower-powered First Watt amps are among the best sounding solid state amps.  I heard one of their SIT amps and I borrowed a J2 amp from a friend for a couple of weeks.

I run something pretty exotic in my pushpull amps-Western Electric 349 output tubes.  A quad of these cost a fortune, but they last a long time, when run gently (my amp puts out something like 5.5 wpc).  My amp is essentially a rebuilt Western Electric 133 amp (input/driver tubes are 348, I use the correct input and output transformers, the power transformer and choke are modern).

I am not quite as extreme as you are, given that my speakers are 99 db/w efficient, but this is still quite below the power a lot of people seem to think they need.

I agree that 3 db is quite a bit of difference in sound level and I share your experience with channel balance.  I use to run a Levinson No.32 linestage that allows for 0.1 db changes in volume.  That gradation seemed ridiculously fine.  With most musical sources (i.e., not a steady test signal) it is a bit hard to hear a 1 db change in volume.  But, in terms of channel balance, it was quite easy to hear a 0.2 db change to one channel.  That explains why Levinson offered such small changes.  I don't like stepped attenuators which have so few steps that there is more than a 1 db change between steps--the right volume level always seems to be between the two offered steps.  It is amazing how small is the window on the ideal volume level.  That is another reason why remote control of volume seems essential to me--you cannot, practicably speaking, find the right volume by getting up to manually adjust the volume even if you are not lazy.

I bought my amp from a custom builder who also built my preamplifier.  They are "matched" in a way because the amp has input transformers that demand, for optimum performance, being matched to a line stage or preamplifier with a corresponding output transformer.  I had this combination for about five years or so, and in that time, I would sometime be asked how much power the amp put out and I had no idea whatsoever.  When the builder, who is from Italy, came over to the states, I got to talking to him and I asked him about the output power of my amp.  I got such a look of disdain from him; clearly I did not deserve that amp if I concerned myself with such irrelevant and trivial matters.  He thought about it a bit himself and took a guess (I would not expect him to have actually measured it, how it sounds is the only consideration); he guess 5.5 wpc, which is my answer to anyone who asks.