Power . How much do we need...

[LL21]

Yesterday, i listened to the Burmester CD-03 CD.. ( If you want to really test your system, this is one helluva great Cd for that)...particularly the Yim Hok-Man track .. "Poem of Chinese Drums". I thought my walls would crack:roll eyes: Seriously tough track for any Sub or full range system for that matter. The T5 came through with flying colors, although I was a little worried that I might blow up something.

cool...very cool...

 

[fas42]

To go with the general theme of the moment, yes, you can never have too much power: after all, the Ferrari will still be capable of popping down to the corner shop for a bottle of milk. The main reason this situation has arisen, is that to get higher power designers have used the class AB circuit, rather than class A, in amplifiers, which requires a better quality power supply to work correctly. Overall, the latter approach hasn't been taken so the result is that you have massive power supplies to overcome intrinsic design deficiencies. Of course, the joke is that these class AB amps are working class A 99% of the time, so one has paid a lot of money to get essentially a class A amp.

So a simple rule would be either to get a reasonable, relatively low powered, pure class A, or SET amp, or a massive class AB amp that runs hot, that is, really a class A in disguise. What works are amps with power ratings at the either ends of the spectrum, not in the middle ...

Frank

 

[Whatmore]

Not sure I agree that AB amps are in A 99% of the time.
My previous amp was 50w A/B and it clipped into my 97dB speakers. To paraphrase roger sanders, most people aren't aware their amps are clipping, they just use subjective terms like 'running out of steam' or 'losing soundstage' etc.

 

[fas42]

Not sure I agree that AB amps are in A 99% of the time.
My previous amp was 50w A/B and it clipped into my 97dB speakers. To paraphrase roger sanders, most people aren't aware their amps are clipping, they just use subjective terms like 'running out of steam' or 'losing soundstage' etc.

I was referring to high powered ones that run hot, your Krells, Gryphons, etc. Those descriptions are not of pure clipping, yes, there may be clipping in there, but what's really happening is that the amp is compressing, the power supply has lost the plot so to speak, and the voltage rail is bouncing around like a car wheel with dud shock absorbers ...

Frank

 

[Whatmore]

Im not sure of the technical term but when I see my amp's output hit a brick wall on a CRO I call it clipping

 

[fas42]

Im not sure of the technical term but when I see my amp's output hit a brick wall on a CRO I call it clipping

Hmmm, that combination of amp and speaker should give you a peak of about 114dB at a metre, if the spec's are good, that's plenty loud enough for most people. So you either like listening very loud, or the amp's voltage rail was sagging badly, very badly, at the time, typically because of very heavy bass drive.

Frank

 

[Mike Lavigne]

Still haven't see any solid argument toward using less power

how much amplifier power is enough?

a simple question, but the answer is not simple.

because; it turns out the best sounding amplifiers are not the most powerful ones (IMHO). although some folks might disagree with that.

then there is the fact that whereas in the low frequencies more power can always be better, in the mids and highs more power has much less value. other factors are more important to many listeners.

i will agree that some listeners value more power high enough that to them it's always better. but that is more a matter of taste than of fact. some people like red better than blue too. but red is not always better.

so any amplification choice is likely some sort of compromise.

and that is not even considering that speakers run the gamut of efficiency and impedence load.

so there are just too many varibles to make any sweeping trueism about more power always being preferable.

to demonstrate my point i would submit that a certain subset of SET amps will easily sound better in 'some' ways to 'most' listeners than the most expensive, best, very powerful amplifiers. assuming we do agree with that, then how can one say that more power is always better? better at what? and once we can see that then the 'more power is always better' perspective is not true. it's just not always better. it's only always more.

i will say that assuming one could retain 100% of the quality of any amplifer even while making it more powerful, that would always be preferred. unfortunately the laws of physics don't always allow for amplifer design and componentry to scale like that. there are always trade-offs involved.

 

[mep]

Mike-Are you still enjoying your 3 watts?

 

[Whatmore]

Hmmm, that combination of amp and speaker should give you a peak of about 114dB at a metre, if the spec's are good, that's plenty loud enough for most people. So you either like listening very loud, or the amp's voltage rail was sagging badly, very badly, at the time, typically because of very heavy bass drive.

Frank

It was at loud, but not very loud levels by any stretch of the imagination.
My guess is that very short term dynamic peaks require much more headroom than most people realise

 

[fas42]

i will say that assuming one could retain 100% of the quality of any amplifer even while making it more powerful, that would always be preferred. unfortunately the laws of physics don't always allow for amplifer design and componentry to scale like that. there are always trade-offs involved.

Not so much laws of physics, but rather rationality about energy consumption. You could make a very powerful SET amplifier but it would dissipate staggering amounts of heat, who's going to pay the power bill? And sit in the same room in the warmer months?

The ideal of course is to have all the positive aspects of the SET "set", with the ability to go as loud as your ears will stand in a short term session: it is possible ...

Frank

 

[Phelonious Ponk]

to demonstrate my point i would submit that a certain subset of SET amps will easily sound better in 'some' ways to 'most' listeners than the most expensive, best, very powerful amplifiers

I think this one is in desperate need of a IMHO with a YMMV on the side.

assuming we do agree with that

There's the rub...

Tim

 

[fas42]

It was at loud, but not very loud levels by any stretch of the imagination.
My guess is that very short term dynamic peaks require much more headroom than most people realise

120dB is about the loudest you would want to go for, for replay of conventional music. Precise, sound level measurements within an orchestra playing at full bore, at the position of other players directly in front of the brass, the "worst" spot, gave peak levels just over that, so around 115dB genuine peaks at normal listening positions should be enough, unless you want to recreate a disco ...

Frank

 

[Whatmore]

120dB is about the loudest you would want to go for, for replay of conventional music. Precise, sound level measurements within an orchestra playing at full bore, at the position of other players directly in front of the brass, the "worst" spot, gave peak levels just over that, so around 115dB genuine peaks at normal listening positions should be enough, unless you want to recreate a disco ...

Frank

my iphone app (which only does average SPL) was no higher than about 92dB when it clipped.
I suggest you read the posts in the Sanders Sound forum that I linked before. He explains it far better than I can

 

[Mike Lavigne]

Not so much laws of physics, but rather rationality about energy consumption. You could make a very powerful SET amplifier but it would dissipate staggering amounts of heat, who's going to pay the power bill? And sit in the same room in the warmer months?

The ideal of course is to have all the positive aspects of the SET "set", with the ability to go as loud as your ears will stand in a short term session: it is possible ...

Frank

you are forgetting the other part of that sentence;

unfortunately the laws of physics don't always allow for amplifer design and componentry to scale like that.

in addition to 'the laws of physics' i mentioned 'componentry'. the most low distortion SET amps use the 45 tube and the 2a3 tube. there are simply limitations to how much power those 'components' can develop. trust me, i'm living with that limitation here now in my room. the 2a3 amp builder used every trick in the book to optimize power.

sure; there are other power tubes the 'come close' to those tubes. but close is not the same. as good as the 2a3 is, the 45 tube is still better at low distortion. but it has half the power.

so the lowest distortion tube has the least potential power. kinda supports the opposite of Frantz's perspective.

the question for those seeking musical truth is how little power can you live with? how much crap do you want between you and the musical message?

and right now, this minute, i'd have to say that overall the 100 watt per channel darTZeel NHB-108 is the answer to that question for me. with that much power i get everything. sure, there are compromises compared to the very very best amps at a few particular things. although at low noise floor it is as good as i've ever heard. at grainless musical communication top to bottom it's as good as i've heard. the big dart mono's have more ease and grip. the 45 tube is lowest distortion. the 2a3 has the most detail.

but overall, it does everything right. and since my speakers have 1000 watt amps on the bass, i get my cake, and eat it too.

no doubt the big dart monos would be even better, but at $135k they are not a consideration at this time.

heat dissapation can be dealt with thru various means. i have HVAC that can solve that issue in any case.

 

[Mike Lavigne]

I think this one is in desperate need of a IMHO with a YMMV on the side.



There's the rub...

Tim

if you heard it (the 45 tube SET) i don't think there would be much question about lowest distortion. so no, it's not a YMMV, it's maybe 'you need to go hear a properly designed 45 tube SET'. i'm not saying it's a real world answer for everyone, including myself, but it does do one thing the best.

when i heard it in my system i was bewitched. i had no idea anything could do that. it rocked my world view and destroyed my reference for low distortion. and based on my previous perspective i can understand the skepticism. but that does not change the reality of what it does.

 

[Mike Lavigne]

Mike-Are you still enjoying your 3 watts?

Mark,

for the last 10 days i've been back to the dart's. the dart is an amazing amplifier. it is the best all around amp i've yet to hear.

do i miss the 3 watts? sometimes, but not always.

i'll switch back to the 3 watts in a week or so.

 

[fas42]

my iphone app (which only does average SPL) was no higher than about 92dB when it clipped.
I suggest you read the posts in the Sanders Sound forum that I linked before. He explains it far better than I can

Sorry, your response and Sanders post does not make sense. First of all, forget about average readings, the only thing that matters is peak, will the system create the maximum voltage swing electrically. As for Sander's post, that makes no sense at all: he's either using very, very inefficient speakers, or ones with a really nasty crossover, which is forcing the amp to generate an excessive voltage swing.

Pro audio sorted this sort of thing out years ago: as Tim points out, a decent guitar amp will pulverise your hearing, but it only generates a miserable 60 or 100W, same as your amp, and the speakers in the cabinet are only a few dB more efficient, if that, than 97dB. There's no magic difference between pro and our stuff, just that the pro gear has got rid of the frilly bits ...

Frank

 

[fas42]

you are forgetting the other part of that sentence;
in addition to 'the laws of physics' i mentioned 'componentry'. the most low distortion SET amps use the 45 tube and the 2a3 tube. there are simply limitations to how much power those 'components' can develop. trust me, i'm living with that limitation here now in my room. the 2a3 amp builder used every trick in the book to optimize power.

Ahh, but nothing to stop you running the tubes in parallel, we're talking limitless money, or stupidity perhaps, how about 100 of the 2a3 tubes in such a configuration: be able to hold its own against a Krell!

Frank

 

[FrantzM]

Mike

Let me try to answer your post . Allow me some tangents.

Back in the early days of WBF, Caesar (Him of several very intelligent questions) asked about Education and Audiophile. By Education I think he meant a learning process. We do learn to evaluate equipment and there is some consensus among audiophile of what is good sounding. Most of us will never declare any Bose great sounding. Most people can recognize if something sound very close or similar to a real instruments. It takes some training to grasp nuances and to develop or try to develop a vocabulary that convey auditory sensations or the closeness to the real thing of a given reproduction …
“Good Sounding” is one of those terms that are so fraught with subjectivity as to be , for me at least difficult to use in this context. What sounds good to you might sounds good to me or might not … I do however know that it is entirely impossible to give a good simulacra of a soprano going full tilt in your room with 5 watts on your speakers.. Even Less a Wagnerian score or a Mahler symphony, Do not approach it with Shostakovitch 10th or Kanye West .. Ok you get my drift …
I am not of the advice that it is that difficult to build a powerful amplifier. I would surmise to you that The mighty Top of the line Dar Tzeel which you heard at your place is a supremely great sounding amplifier and on your and likely most speakers, will present a very believable simulacra of a soprano going full tilt or the aforementioned symphonic work or a Jay-Z score… There are numerous amplifiers both tubes and SS that would do the same .. ARC, VTL, MBL, Burmester, Gryphon, Boulder, ML, Threashold, Bryston, etc.. You may not like them and that is OK .. yet when it come to similitude with the real thing.. They would be at ease ... To me that what power is all about and to me that counts.
One may prefer certain thing that a low power amplifier does on a medium sensitivity speaker and that is fine. It is likely limited to a small genre or number of musics or music pieces… I also am surmising the that the flea-power amps highlight some part of the frequency band because their response in other parts are not as good … kind of reducing the bass volume (assuming that a speaker can do that) to listen to more mid-range.. If at the end one derives pleasure from this… Fine. Mission accomplished … But In term of verisimilitude, that is like-ness to the original even , I am not sure the flea-power will match the Dar Tzeel on most if any music score … I may prefer what it does and often what one prefers may not be what is accurate .. Kind of preferring Tang to Orange Juice an example that many people don't like but which to me conveys the idea very well. If you like something and derives pleasure from it .. That is to me fine ... End of debate..

And there is the pure objective aspect of the story when the flew-powered amps find itself out of steam what does it do .. What can it really do? However superlative its performance was up to this point which is reached very quickly with most modern speakers? It clips and while clipping is what guitar players wish .. Reproducing a wave with any semblance of accuracy is not the province of a clipping amplifier.
Thus my position that all things being equal … The more power I can get to my speakers, the more I will provide them… And frankly for the price I see some of these flea-powered amps going for I would say that I will be more comfortable with gob of watts than with sub-10 watters … For the speakers I am thinking about these days (yours being very much part of my list maybe at the very top of it)

 

[fas42]

when i heard it in my system i was bewitched. i had no idea anything could do that. it rocked my world view and destroyed my reference for low distortion. and based on my previous perspective i can understand the skepticism. but that does not change the reality of what it does.

I know how low "audible" distortion can go also, which is why people don't need to worry about the future of high end sound. Sooner or later, there will be a critical mass of people who "get it", and then the industry and people's enjoyment of what reproduced sound can truly deliver, will move forward in the next stage.

Sorta like getting past the end of level barrier, or monster, in a computer game ... :b

Frank