does more power=better quality ?


in term of sound quality in amp? does more power give you better quality.I understand it give you better control of the bass. how about mid and high?
is a 300watts ( krel, levinson,rowland, audio reserach ..etc ) better than a 200 or 100 watts model within the same company and product line? what if you have a relatively efficient speaker?
a1126lin
I think this question has been ask many times here. More power equals better sound only if you or your speakers actually need it. Here's a SPL Calculator. It's fun to play with and gives you an idea of power needed. If nothing else it's fun to play with.
No...better designed components with superior parts = better sound quality....IMO. I have listened to some 50 and even a 25 watt amp ( 1 was running in class A mod ) that were absolutely incredible.
No, it never has. I have heard many 200 wpc amps that sounded extremely different from one another, but there was a time when 200 wpc was the peak of what could be had. Some of those amps sounded no better than many of their lower powered counterparts, while others blew them away.

It is the quality of the product not the numbers that people use to represent it, that makes one amp better than another, unless you worship Julian Hirsh...
I agree with Nrchy. You can make a "cheap" high powered amp,that'll sound like crap and also make an amp with very very few watts and it can sound gorgeous.Doesn't matter what they look like either it about whats inside that counts.Most Audiophiles will tell you give me quality watts and i can build something around it...
A1126lin,

The reason for the seeking higher power is "linearity".

If amplifiers were perfectly linear - that is their
characteristics were independent of the magnitude of their
output, then Gmood1 and Nrchy above would be correct -
there would be no advantage to having more power than
you need.

However, amplifiers are NOT perfectly linear. They are only
approximately linear. One way to stay within the most
linear regime of the amplifier's operating characteristics
is to use a small fraction of the amplifier's ultimate
power. That is the more the amplifier "loafs" - the
better.

Who would you trust more with lifting a prized breakable
possesion weighing 40 lbs - someone that can lift 60 lbs
or a longshoreman that routine lifts over 100 lbs?

The less the load "taxes" the amplifier - the better.

Now does high power necessarily equate to better quality?
Certainly NOT - Thorman is correct there.

The design of the amplifier, the quality of the components,
etc; all are factors affecting the quality. However, all
else being equal - the more powerful the amp - the more
you stay in the linear regime of the tubes or transistors
that make the amp work.

You also have to be cognizant of the fact that the response
to power is logarithmic. That is 300 watts is only a
1.76 dB increase over 200 watts, and only 4.78 dB over
100 watt power level.

So what may look like a large increase on a linear scale -
is actually only a small increase on a logarithmic scale.

Dr. Gregory Greenman
Physicist
A1126lin, I think your question is rhetorical, at least I hope so. As Gmood1, Nrchy and Thorman already said, quantity and quality have never been the same thing—and I don’t think they will ever be. I would like to bring up a couple of additional issues that are relevant to your inquiry.

Throughout the years, the best sounding solid-state and tube amps in the midrange—with some notable exceptions—tend to be those with low to medium power. This may or may not be a coincidence as high power tends to require pushing the design and the parts to work closer to their limits with unavoidable penalty in the sound.

The other important parameter in selecting the power of an amp—the most important one in my opinion—is your listening preference. If you like small-scale, intimate music, you’ll be very happy with low- to medium-power amp. If you like heavy rock music and large-scale symphonic music with thunderous bass or subterranean organ notes, you’ll never be happy with low- or even medium-power amps no matter how efficient your speakers are.

I run into this dilemma all the time so I have both medium-power tube amp and high-power solid-state amp in my system and use one or the other depending on the kind of music I listen to. But switching amps is a pain in the neck. Bi-amping solves most of the problems though not all but thatÂ’s another story for another time.
I think we are getting a little off track. If I understand the poster, he is asking does a (for example) Classe CA301 sound better than a Classe CA201. A comparison of the same line is what he is after. My response would be that it depends on the sensitivity of your speakers. However, in the case of the classe, the 201 sounds quite a bit better than the 101. Not necessarily because it have more power, I'm not really sure why. I think you will find the same thing within the pass labs line. The 250.5 will sound better than the 150.5.

I think in most cases, this is true, but not all of them. Again, I think it largly depends on your speakers.
No, but............

In the case of what some like to call "digital switching amps":

Taking a given module, and operating it at both the lower and upper end of its operating range, most listeners prefer the sound at the upper end of its range. Mainly because it "sounds" like it has more drive.

Since the stored charge in the supply caps, and therefore the amount of energy available on short transients, is the product of the voltage squared times the capacitance, raising the voltage makes a more dramatic effect than raising capacitance.

So, if that is your main consideration in determining sound quality, yes, there is a valid reason why it could be true.

In the case of a Class AB amp, operating at a higher voltage reduces the capacitance in the devices that determine the bandwidth and phase margin of the amp. Both of these could lead to minor improvements in sound. But only up to a point. Beyond that, the changes are negligible, and other factors enter in that make amps harder to build.
With apologies to Anarchy with whom I disagree on most everything, all other factors being equal: yes. The more clean power the better. If you listen to the call of the sirens you will get just the opposite view and may wind up with a two watt SET!

P.S. And insofar as the ambulance chasing bit from Anarchy, why not come up north and tell me in person.
S7horton,

Let's take the comparison of the Classe CA301 at 300 watts
and the Classe CA201 at 200 watts.

If the design of the amps is essentially the same, and Classe
selects components with the same quality; but it just puts
more transistors in the CA301 than it does the CA201; then
yes.

For the same load, the transistors in the CA301 will each
be providing less current than their counterparts in the
CA201. Therefore, because the transistors in the CA201
are putting out more current - they are farther out on
the transistor's response curve. Depending how linear
that curve is - indicates how much less accurate the CA201
will be than the CA301.

If the curve was perfectly linear - then there would be
no difference. But real transistors never have perfectly
linear curves. The CA201's transistors are extending
farther out on the curve than the ones in the CA301,
because the CA201 has fewer transistors to carry the same
load.

The difference may be marginal, if the transistor's
characteric curves are fairly linear; but there is a
difference because the curves for real transistors are
never perfectly linear.

Dr. Gregory Greenman
Physicist
thanks for all the inputs.
i should elaborate more on my question.
let say if i use a bookshelf speaker ( revel m20 or bw 805). i get the impresseion from some post that lower / midpower sounds better than the higher power model ( within the same brand ) for example. some have say pass x250 sound better than the x350, or a krell 100 watts sound more sweet( whatever athat means ) than a 600watts krell amp ( again same company and same line product) i was comparing a sony receiver to a levinson amp.
i like to know is it true and why
My 300B SET puts out a whole 8 watts. It's playing 98db speakers with a flat 8 impedance. Hm! Would you say it's loafing? It sure sounds better than any high power amp (Tube or Solid State)that I've owned or had the pleasure of listening to. I've heard some pretty good S.State high power driving stats. or other difficult speakers also. It's about having the right gear for the grade!
Assuming relatively sensitive speakers with a fairly benign impedence, my experience is that lower-powered amps tend to sound better, as there are fewer output devices to muck up the signal. More output transistors or output tubes means more circuitry and more transistor rush / more tube rush -- this can be very audible in a revealing system (in the form of lost transparency and detail). This is one of the advantages of simple single-ended amps, which tend to have one (and maximum of two) output devices.

While the comparison is obviously very inexact and there were a lot of factors at play, a friend and I once spent several hours listening to a wide range of music on a potent $200K Krell / JM Labs Grande Utopia system at Singer. We then went into a smaller room and listened to a VAC Renaissance 30/30 (32 watts/channel) power a pair of Meadowlark Blue Herons. The VAC / Meadowlark system embarrassed the Krell / JM Labs system -- we just sat there looking at each other, shaking our heads.
Hey Raquel, I am shaking my head now too after selling my Krell 750 monos, KCT and Wilson MAXX for the VAC PHI Preamp, VAC PHI 220 Mono's and a little pair of Caravelle Monitors supported by a Velodyne DD-15 inch sub! I have never had a more dynamic, musically satisfying system in my life with the most unbelievable depth of soundstage I have heard in any system anywhere. More money and more power doesn't always mean more satisfaction. I learned the expensive way!
"there are fewer output devices to muck up the signal" is it kind of like thecar analogy.for the uninitiated ,non engineer . can you use the analogy of a car.just because you put V8 engine, the car may accelerate better but it doesn't always handle better. some peoplle may preferred a mini cooper vs a corvett because they feel the mini handle's better.
The problem with all the comparisons to 8 watt SETs...
is that "all else is not equal".

Philefread,

Your 8 watt SET amp IS "loafing".

That 300B tube is capable of more than just 8 watts.

That tube can be used in amps putting out on the order
of 40 to 50 watts. For example, Cary uses it in a
15 watt SET power amp:

http://www.caryaudio.com/products/audio/cad300se.shtml

Therefore, in the context of my discussion on linearity -
the tube is not being taxed at all.

Your 300B SET amp is not limited by the 300B tube - it is
limited by the power supply.

The designer / manufacturer of your amp put in a low power
power supply - so you can't push the tube to anywhere near
its capability.

The manufacturer forced the tube into "loafing" by pairing
it with a relatively "anemic" power supply.

Your speakers may be relatively flat - but they don't have
an absolutely flat 8 ohm impedance. Do your speakers have
voice coils? Voice coils are inductors - and the impedance
of an inductor is not flat - it varies with frequency.

Dr. Gregory Greenman
Physicist
Raquel,

The problem with your argument is that in amps in which
there are more than a single output device; the output
devices are in parallel.

No - the signal is not going through more circuitry - all
the electrons see the same amount of circuitry. It's just
that all electrons don't see the same components.

If you have a tube amp with 2 paralleled 300B tubes; all the
electrons saw a single 300B output tube - just not the
same one - 50% saw one tube, 50% saw the other.

The comparison at Singer is worthless. A VERY BIG factor
is the size of the room. One was smaller, one was larger.
The rooms therefore had different resonant frequencies -
and Lord only knows how that affected the sound.

You can't conclude anything even remotely meaningful from
two different rooms, with two different speakers, with
two different amps...

Dr. Gregory Greenman
Physicist
Output transistors run in parallel need to be trimmed to work properly, and they are now up to trying lasers to get this right (Edge), which they really can't. If output tubes are used, they have to be properly biased (or self-biasing), and they are often not at peak bias in practice, thus introducing hum and other discontinuities into the sound.

The more output devices you have, the more collective residual noise you have. This becomes an issue with a system that features highly revealing upstream components, top cabling and top speakers, all fed by a well designed A/C power supply and set up carefully in a good room. Extra output devices are simply not needed if you have the ability to buy sensitive speakers with a benign load impedence. In addition, the more output devices there are, the more one is likely to fail (output tubes are generally easy to replace, but output transistors in well-known SS amps as young as ten years old have been known to go out of production, making the amp a door stop).

I qualified the Singer anecdote thoroughly -- read what I wrote again.

While a monster amp is desirable with inefficient speakers, this is just not the way to go in my opinion -- partnering sensitive, easy to drive speakers with an amp that uses a simple circuit featuring a minimum number of output devices and the very highest quality parts will yield superior sound. High-powered amps have a use -- digital home theater systems, where maximum dinosaur stomping seems to be the goal -- they are a poor choice, in my opinion, in high-end, two-channel analog-based systems. In short, I stand by what I wrote.

PS - My amps run 300B's -- now that's a linear amplifying device.
"More transistor rush / more tube rush"

What on earth are you talking about?

No, multiple devices don't need to be trimmed, although it helps to make sure that one device doesn't hog all the current. That is what all those nasty resistors are there for: to minimise those effects for guys to lazy to spend a few pennies to match them.

BTW.......there is an optimum value for the voltage drop across those resistors, but that is way off topic.
are all output transistors created equal.given the same manufacture, mode...etc do they all sound alike?
if not, is it possible to have just one output transistor?
...of countinous power with minimal distortions throughout an audiable freequency bandwidth preferably including subharmonic and ultrasonic areas as well.
I'm glad someone let me in on the Anarchy thing. I was lost on that for a minute.Actually I'm still not clear on it.:-)

Going from a listening stand point. I've always prefered the simpler designed amplifiers. The sound was always more open and transparent too me. I equate this with less is better in the signal path. Easily heard not necessarily on a expensive system but on a simple system with fewer bottle necks. Will 6 wpc do it for everyone ..no it won't.

But it works wonders for me. Hearing the difference in cables,sources and other components has never been easier to do.

Oh and yes there are amplifiers with single output transistors. Mine has no output transistors as far as I know. Atleast not the traditional ones like mosfets or bipolars.
People who have Magneplanar speakers, and people who have Lowther speakers know the answer to this question. YES, and NO, and both are correct.
Raquel,

Yes - I read your Singer anecdote - and noted the qualification.

However, the conditions of the comparison made that
comparison absolutely WORTHLESS.

So worthless - that it shouldn't even be brought up -
qualifications notwithstanding.

I reject your contention that there is one "way to go"
in audio system design - efficient speakers and relatively
low power amps.

Some well executed speaker designs, for example ribbons;
are inherently low efficiency and require high currents.
You can only make a permanent magnet so strong. A ribbon
driver has inherently a single turn in its "voice coil" -
so unlike dynamic drivers where the efficiency can be
increased by putting more turns in the voice coil - a
ribbon can't take advantage of that technique. With a
limited strength magnet, and a single turn - the only way
to get more output is the third term in the equation for
the Lorentz force - the current. The impedance must be
lowered to obtain more current. However, that means a
more powerful amp.

That approach is every bit as well considered as your
approach.

As far as the 300B being linear - ARE YOU KIDDING!!

Have you ever put a 300B on a test bench to determine
the linearity? I have - and I would NOT say that they
are champs in the linearity department.

One can make an amp that sounds very nice to those that
like the sound of the 300B, but please don't say it is
anything special when it comes to linearity.

Dr. Gregory Greenman
Physicist
Eldartford,

Very good - I agree with you 100%

All else being equal [ which is the key ], the more
powerful amp is more linear.

Some audio systems - some speakers - require the higher
power amps; like the ribbons of a Magneplanar.

Some speakers are very efficient and won't tax even a low
power amp - thus keeping it in the more linear regime.

I get really irked by people that say there is ONE WAY
[ usually their way ] to accomplish a given task.

If that were true, we'd all be driving the SAME car,
because there would be only one BEST car, watching the
SAME TV, because there would be only one BEST TV....

There are a whole host of different philosophies. Any
engineer will tell you that engineering is about making
compromises and trade-offs. You trade one set of advantages
for a set of disadvantages. What choices one makes is
determined by what they value.

As the old saying goes - "That's why they make chocolate
and vanilla!" Chocolate is NOT necessarily the one BEST
choice in ice cream.

Dr. Gregory Greenman
Physicist
Raquel,

Here's the web page of someone that has actually tested
the tubes they're dealing with:

http://jcverdiervalvevinyl.online.fr/Kinky300/300Binfo.html

The quality of the tubes varies - which is true of
every manufactured component. However, it is especially
true of hand-assembled devices like vacuum tubes.

However, one can see that even in the tubes labeled "perfect",
there is a degree of non-linearity. The plate characteristics
curves are not perfectly straight - and they are not
perfectly spaced.

The author is correct that they are "perfect" - but
perfection only goes so far with a hand-assembled
1935 designed electronic device.

The 300B is not bad for a tube designed in 1935.
In fact, it's a rather impressive tube for a
device that did not benefit from modern computer
modelling, and modern electronics manufacturing
techniques.

However, one can produce devices with better linearity.

Dr. Gregory Greenman
Physicist
A little off the subject but seems somewhat relevanet. Given the argument that fewer devices, simpler design, gives a better quality sound, less to mess it up, would an OTL amplifier be a more reasonable solution, rather than looking at power alone, to question of sound quality?
Power and simplicity are favorites of mine. Any thoughts would be appreciated
How do you trim a transistor with a laser? Would a sharp razor blade work?
morbius@attbi.com: My friend, what to do with you.

Cdc: Fair question. I meant to write "match", not "trim". Sorry.
Uru975...Eliminate the transformer, and what do you get? About a dozen output tubes!
entirely dependent on a good match with a loudspeaker. tubes vs transisters is as much an astetic choice as a sonic one. just try to stay within the recomended power for your speakers.
morbius:

A last point ... the experience at Singer was anything but worthless, and I'll give you the benefit of the doubt and assume that you are being handicapped by misplaced reliance on the scientific method in thinking that only a direct A/B comparison between amps on exactly the same system in exactly the same room is valid. Those amps were not designed to be used in the same room and with the same equipment, much as your example of Maggie power requirements illustrates. Further, each amp will favor different types/brands of cabling, making their use with the same cabling an error. One is a Class-A biased triode design feeding speakers through an output transformer, the Krell monos being solid-state designs that are probably Class A up to a point and AB thereafter. Fortunately, Andy Singer is not a physicist, but a hi-fi man, and in recognition of these differences, the amps were set up in different rooms in different systems, to live or die on their own merits. In short, the only worthless comparison would be a direct A/B in the same system -- it would tell us nothing.

PS - Why do I picture you wearing one white sock and one brown sock? Your thoughts about about automobiles, televisions, ice cream, proper comparisons, 300B's, and absolutism were unsolicited and are worthless to me (and I don't need upper-case font like you do to make my points -- how presumptuous to think that I would allow you to address me that way -- how obnoxious you are).
Raquel,

In addition to all the differences between the two systems
that you note - the rooms had different room modes - they
accentuated / deaccentuated different frequencies. That's
probably the biggest factor making the comparison of the two
systems invalid.

When comparing audio equipment - at least stick to the same
or similar rooms. You'd be surprised how much the room
alters the sound.

As far as you thinking of me with mis-matched socks, that's
just your own prejudice showing in thinking of me in a
stereotypical fashion; a stereotype that has little backing
in truth. I'm not a stereotypical scientist; I don't know
any who are.

However, I am enough of a scientist to know that all the
fine points of audio have physical explanations. There's
no "magic" at work in tne audio field.

Dr. Gregory Greenman
Physicist
Please don't lecture me on room acoustics. Singer is a good shop and
has its rooms professionally treated in an attempt to smooth out modes
(they also do not put any top-shelf equipment in the square rooms).
While this will almost never take the rooms out of the equation, the
systems to which I refer were set up properly in treated rooms.

My comments about socks had nothing to do with prejudice, which
basically means prejudgment before seeing the facts. They were post-
judgments made after reading your ill-reasoned (not to mention
pompous) comments. Go away.

Nb: My apologies to the author of this thread for where our comments
went (this fellow was really asking for it).
Raquel,

I'm well aware that Sound by Singer is a well respected
audio dealer - and they set up their rooms properly.

What you fail to appreciate is that you can't take the
room out of the equation. No matter how you treat the
walls of a room - the walls still reflect sound.

My comments are not ill-reasoned. Solving the wave
equation that dictates the propagation of sound in air
is one of my specialties.

The propagation of sound in a room is dictated by the
wave equation; a second order partial differential equation.
Mathematics requires that one provide "boundary conditions"
in order for the problem to be well posed.

The walls of the room provide those boundary conditions.
No matter how you treat the walls - they still reflect
sound to a degree. Because of the reflection of sound from
the walls; you get "room modes".

For example, if the room is 20 feet in some linear
dimension - length or width - then there are room modes
at frequencies of 26.6 Hz and 53.2 Hz corresponding to
a half-wavelength and a full-wavelength fitting that
dimension, respectively.

This gives you "standing waves" at those frequencies -
the music at 26.6 Hz and 53.2 Hz will be accentuated.

If you move to a different room, with different dimensions,
then different frequencies are accentuated.

There is no way that the people at Sound by Singer can
get around this. It is just a simple fact of life when
it comes to audio, that is dictated by the Physics of
sound travelling in air.

Because you auditioned two different systems, in two
rooms that you stated were different in size; then the
rooms were accentuating different frequencies and thus
you would have heard differences even if you were listening
to the exact same audio setup.

Because you don't know what the room is doing to the
sound, any comparisons where the room acoustics are
different is invalid.

Dr. Gregory Greenman
Physicist
As I wrote, I know the room cannot be taken out of the equation.

In any event, your response was not conclusory and was respectful this time, and I am not a scientist, so I won't be debating you on room modes (if I could only get rid of mine). That said, I continue to question the worth of your viewpoint for the reasons stated in my prior comments, and direct you to John Atkinson's pg. 1 editorial in this month's (July 2005) edition of Stereophile, which, although not this precise issue, touches on the issue of blind testing and its relevance to demo'ing hi-fi gear.

I take this opportunity to return to my original point, to wit, my experience has very much been that lowered-powered amps, assuming reasonably sensitive speakers, tend to sound cleaner and more life-like than mega amps. This is the result of having heard and owned a lot of equipment since 1977.
Raquel,

Again, you ignore the science that all else being equal,
the higher power amp is more linear - that's just a FACT
of science.

I've read John Atkinson's pg 1 Stereophile editorial. I'm
not commenting on blind testing at all. I'm talking PHYSICS!

You may have heard a lot of equipment since 1977, but I've
both heard and measured equipment since 1977, and I know
the physical principles on which audio is based.

You can't get around the fact that the less you push the
active devices - be they tubes or transistors - the better.

Real tubes and real transistors are not linear.

The problem with audiophiles that only listen and never
measure is that they confuse what they like for accuracy.

I've experimented with audiophile friends, where I distort
the signal on purpose - rolling off frequencies, altering
time constants, etc. and the audiophile prefers it!

I believe a lot of audiophiles prefer music that has had
the harsh "edges" removed by some wimpy amp. You may
prefer it - but it is not accurate.

Real musical instruments have these "edges".

From your listening experience, though vast, you can only
say what you like - you can't say what is accurate.

Accuracy comes in making comparisons of REAL instruments
with recordings of THAT instrument - which is what I've done.

You can't make a blanket statement that low power amps
are "cleaner". The only thing they've "cleaned up" are
real characteristics of real instruments.

Dr. Gregory Greenman
Physicist
"I believe a lot of audiophiles prefer music that has had
the harsh "edges" removed by some wimpy amp. You may
prefer it - but it is not accurate."

This may hold some water. But it isn't the case with all of us . Now your making blanket statements. Not all flea powered amps are created equal. I can't live with warm and fuzzy. Just doesn't work for me.

I've heard high powered amps that round edges off and make all recordings sound like I have cotton in my ears. My flea powered amp doesn't do this. I do not want to argue just trying to clear the notion that all low wattage amplifiers smooth over the recordings.

Good Listening!
Morbius:

As for blanket statements, I wrote "my experience has very much been that lowered-powered amps, assuming reasonably sensitive speakers, tend to sound cleaner and more life-like than mega amps." The words "tend to sound cleaner" prevent this from being a blanket statement, assuming a minimal understanding of the English language.

PS - Unlike you, I do not provide my name and profession when posting on public Internet forums, but I will give you a clue as to my profession and say that, should you ever be offered a chance to provide expert testimony in litigation, be it in a matter involving your specialty, hi-fi or anything else, you will definitely want to pass.

I am now out of this insipid exchange.
Raquel, I've followed this thread with interest and I want to congratulate you on your brilliance and fairness. The law profession is lucky to have you. As for the pompous little bully, we can only pity him for needing to proclaim himself with his scientific qualifications and HUGE FONTS to compensate for something we don't want to know about.
I too have followed this thread and was interested to read an engineering/scientific point of view as to why a higher powered amp has the potential to be more refined when it has more amplifying devices. And I feel Mr. Greenman made a fair and honest attempt to explain this. As for him being labeled a pompous bully, I don't see the justification for this at all. At least he has the integrity to sign his name here.

As for the use of huge fonts, I suspect it is due to his frustration that his measured lab results are at significant odds with claims by others on device linearity, semiconductor theory, etc., that are more based on home and audio shop listening experiences, magazine reports, etc., than bench testing.

It's always unfortunate when a thread of potential value results in a game of "I can write and speak better than you, so my advice to you is to not even bother trying to beat me here". It matters to me not at all how someone speaks in court as it's all a game of whose more clever with words and very little substance there anyway. But trying to discern why and how two amplifiers of a same company may sound different strictly due to the number of power output devices....now, we have some substance. And the simplicity of a set of graphs comparing device linearity, should be rather straight forward to present even to a court room.....well, one where the judge or jury has at least some level of technical competence. But I'm not even going to get into that.

If I went to an audio shop and the sound of a $200k system was no match for a system in another room, at a fraction of that cost, the only conclusion I'd make is that the owner of that shop needs to get in that high priced room and find out what is wrong. Until that was resolved, I would not give a lot of credit to the shop owner beyond his/her ability to throw high-priced products together in an attempt to impress others. And if I did suspect it was an amplifier fault or difference, I would definitely want to hear another amplifier in that system in an attempt to eliminate the amp as the cause of the problem or lack of "musicality".

Oh, and the issue of linear amplification ........ ah yes, the Convergent Audio Technology JL series.

John
I have been listening to music since before a 45 watt ss amp was the biggest baddest thing around, a Sansui AU999, for those who remember.
Graphs, are indeed a point for noting and do indicate basic paramaters for measurement, squarewave formation, slew rate, etc. There is though a basic and real diffeence between measurement and music.
I cannot prove this, but I believe with enough info it would be quite able to get two different amps, even different types of amps, at equal wattage whose reaasurements were commensurable but whose sound was not.
Measurements are a good starting point but I believe a poor ending point. Yes, I do prefer the sound I search for via various components, cables, power cords, and sources. It may or may not be neutral, authenticly-live, etc. but it is what I like. I believe the good doctor and the good lawyer were talking past each other, their points were not so much mistaken or even misspoken as not heard.
The Drs. view that audiophiles may prefer a less than measured neutral actual live sound may indeed be true.
The lawyers that lowered power amps tend to sound clearer etc. is probably also true. It is his ears after all. OUrs may listen differently.
Getting all hot because the specs and measurements are so cool is a good starting point but a poor buying one. Once again Trust your Ears. And perhaps agree to disagree when necessary
What an interesting thread, amongst all the angst and outrage, some telling points have been made and I've learnt a lot. The only fair conclusion is that there is'nt one, some of the assumptions are revealing, particularly the one that the more accurate and more "linear" the response the better. A good audiophile attitude, but I am, one afraid I don't subscribe to,I like a system whose sound I enjoy with the music I listen to. Accuracy and linearity can go hang.
It seems to me that "low Powered amps" bring certain advantages to the party that allow them to be driven nearer an amps power limits and into areas of higher distortion. The obvious example here is the "soft clipping" of tube amps, possibly due to there tendency to even order harmonic distortion. I would also argue that a class A Watt and SET watt is not the same as a Class A/B, SS watt and I do'nt think that is contentious. So even if amps are driven into areas of distortion, there are good reasons why this is less of a problem in high quality, low powered amps.
Another point I would take issue with, is that in a given range, a higher powered, more expensive amp will sound better than its lower powered brother, into the same speaker. Given the proviso that the amp is matched to a sufficently sensitive speaker, there are many examples where the lower output amp gives better results. I would suggest here the Pass labs Aleph 3, at 30 watts, the lowest powered and arguably the best sounding of the Aleph range.
To consider speaker choice, a good high sensitivity speaker with benign impedence allows the use of low output amps, I use Living Voice Avatars with an 845 SET, to great effect. That does'nt alter the fact that many of the very best, full range speakers, are power hungry. You can't run Wilson Grand Slamm or BandW 800 Nautilus on a 3 watt 300B SET. That does'nt make the speaker a bad choice.
It's not suprising, I suppose, how many of the threads on this site end up with "it all depends", or "on the one hand X and on the other Y". Few things in life are straightforward and there is'nt one valid approach to system building. The only responses I am dubious about start "well it's obvious" or "the only valid approach is". Frankly if there was only one approach, life would be a bit boring.
It seems to me that "low Powered amps" bring certain advantages to the party that allow them to be driven nearer an amps power limits and into areas of higher distortion
That's a statistical conclusion rather than a fact of life: it's very difficult and copious and much more expensive to produce MANY outstanding watts.
1) Very good amplifying devices (like the 845 tube or the 300, etc) only offer a few db's of gain. More gain increases the complexity manifold... bipolar transistors and Jfets can be good too, but if you want many class A watts, you'll probably end up with mosfets... SO, there's a good choice of devices offering a few excellent watts for less than the price of a new house -- but very few giga watt equivalents (for less than the price of a new house).

2) It makes more practical sense to choose a very sensitive speaker since there is lots of choice out there, and the price levels are comparable to their insensitive brethren.

3) Many tube designs offer their best performance at 1-3W. Many ss devices offfer their best performance level at full power.
When someone says "It makes more practical sense to choose...", what they really are saying is "It makes more practical sense to ME to choose..."

In a perfect audiophile world I actually would agree that high sensitivity speakers are the way to go, but in the real world there are limitations with that approach. For a wide variety of reasons, some logical and some not, there is a limited availability of practical high sensitivity speakers. By practical I mean reasonably full bandwidth (40Hz-20kHz), capable of at least 100dB playback and are not overly large, at least by audiophile standards. Such speakers are available, but it's not as if you can walk into the average hi-end retail store and find one.

For better or for worse the marketplace is dominated with medium sensitivity speakers and 30 to 100 watt amplifiers. Such systems are capable of truly excellent performance. As you move out of the audiophile mainstream you will encounter problems -- availability, cost, limited choices, more critical system matching, less trouble shooting support, etc. For any given person overcoming these "problems" may well be worth the effort, but not all people would agree.

Gregm, "ss devices offer their best performance level at full power". Where does that come from?