What are the advantages/disadvantages of different amp topologies?

[DasguteOhr]

Other way round, I was always referring to the degree of compensation, picking you up further above on “truisms” (nothing’s perfect - what else is new?) and absolutes (your disregard for the spectrum in-between, which directly translates to a lesser degree of compensation being the goal, the point @DasguteOhr tried to make from the get-go).

Greetings from Switzerland, David.

In the broadest sense, it's about synergy, finding the right lid for the pot without bending everything. Connecting a sterile sound DAC to a set amp in order to get a good sound doesn't make much sense.
I prefer to keep devices and speakers at the neutral level. The advantage is that you may have options for replacing devices without suffering from a sonic disaster

 

[acousticsguru]

Your understanding of physics is ok, your understanding of what amps I mean is not. Your SETs go to MHz? I think not…

Spectral? Are you even reading your own posts and people’s replies to them? I never said any of my other amps have greater bandwidth than those.

Greetings from Switzerland, David.

 

[acousticsguru]

No, you said must measure bad…without qualification about what you mean by bad. If you mean psychacoustically irrelevant, then that holds for all measurements unless put through an algorithm that correlates the numbers with listening results.

If they sound bad, they must measure bad - provided one measures what’s relevant. I don’t care about the standard excuse that engineer minded people only measure what’s measurable - that itself is the crux of the matter. You’re a scientist yourself: do you support the idea it should preoccupy itself and us with irrelevance?

Greetings from Switzerland, David.

 

[morricab]

Spectral? Are you even reading your own posts and people’s replies to them?

Greetings from Switzerland, David.

Don’t play dumb! You aren’t using that amp currently. You use Amplifon and Decware and occasionally Line Magnetic. None of which have a bandwidth of <100 kHz. Besides, the Spectral is definitely not your best sounding amp.

Your argument that you find wide bandwidth amps sounding best is a red herring. There is no sonic evidence that this is true…even your switch to SETs belies your own hypothesis! Even Spectral needs special cables to reduce the bandwidth and prevent oscillation that can destroy the amp. What good are MHz that have to be truncated anyway? They just didn’t put it inside the amp like sensible designers do. What other wide bandwidth amps do you think sound better than others?

 

[morricab]

If they sound bad, they must measure bad - provided one measures what’s relevant. I don’t care about the standard excuse that engineer minded people only measure what’s measurable - that itself is the crux of the matter. You’re a scientist yourself: do you support the idea it should preoccupy itself and us with irrelevance?

Greetings from Switzerland, David.

You cannot say this. The data itself only tells a small part of the story. Without a model of hearing that is accepted and an algorithm to process it through you can only get a rough idea.

By your logic, Spectral also measures bad.

 

[acousticsguru]

No, you said if it sounds bad and measures good then it actually measured bad. I pointed out that by objective standards it almost certainly measured good…probably as good or better than Spectral, which I know you like (or you did in the past).

To answer this more specifically: I occasionally miss the realism of e.g. a kick drum or cymbals crash as played through Spectral, but have been listening mainly to classical lately, and found an SET that I happen to find more dynamic and lively than most, and whose overall sense of rightness works with all kinds of music, including mediocre quality recordings, as great a compromise as I’ve heard. Besides, the warmup with Spectral is a major problem - they’d really need to be left on eternally to sound at their best. That’s a comparatively lesser problem with tube electronics, even big chunks of iron.

Greetings from Switzerland, David.

 

[acousticsguru]

Don’t play dumb! You aren’t using that amp currently. You use Amplifon and Decware and occasionally Line Magnetic. None of which have a bandwidth of <100 kHz. Besides, the Spectral is definitely not your best sounding amp.

Your argument that you find wide bandwidth amps sounding best is a red herring. There is no sonic evidence that this is true…even your switch to SETs belies your own hypothesis! Even Spectral needs special cables to reduce the bandwidth and prevent oscillation that can destroy the amp. What good are MHz that have to be truncated anyway? They just didn’t put it inside the amp like sensible designers do. What other wide bandwidth amps do you think sound better than others?

How come others play dumb when you misread their posts? I said “tentative” for a reason: my experience as an audiophile over the years, rather than factual evidence tells me that bandwidth matters - to be honest I wasn’t aware this may be considered a red herring.

Greetings from Switzerland, David.

 

[acousticsguru]

To answer this more specifically: I occasionally miss the realism of e.g. a kick drum or cymbals crash as played through Spectral, but have been listening mainly to classical lately, and found an SET that I happen to find more dynamic and lively than most, and whose overall sense of rightness works with all kinds of music, including mediocre quality recordings, as great a compromise as I’ve heard. Besides, the warmup with Spectral is a major problem - they’d really need to be left on eternally to sound at their best. That’s a comparatively lesser problem with tube electronics, even big chunks of iron.

Greetings from Switzerland, David.

Yes, one shouldn’t connect an antenna to the output of an amp that’s able to amplify radio frequencies. That’s intrinsic to its design and not a design flaw.

Greetings from Switzerland, David.

 

[acousticsguru]

You cannot say this. The data itself only tells a small part of the story. Without a model of hearing that is accepted and an algorithm to process it through you can only get a rough idea.

By your logic, Spectral also measures bad.

Why? Because you don’t like it?

Greetings from Switzerland, David.

 

[DasguteOhr]

Spectral? Are you even reading your own posts and people’s replies to them? I never said any of my other amps have greater bandwidth than those.

Greetings from Switzerland, David.

I would be a little careful with superlatives, a Sansui 919 amp can do 5 megahertz sine and it has better tonality. There are some videos about it on YouTube. my all-time favorite integrated amps sansui au 11/111 and 717and 919.if you find a better one tell me.
Maybe someone will give me a pioneer a 27 amp before I die, unfortunately that won't happen. hope dies last.

 

[morricab]

How come others play dumb when you misread their posts? I said “tentative” for a reason: my experience as an audiophile over the years, rather than factual evidence tells me that bandwidth matters - to be honest I wasn’t aware this may be considered a red herring.

Greetings from Switzerland, David.

I will be blunt then, bandwidth in an amp doesn’t matter much beyond human hearing . Your experience doesn’t even bear that out…you have (at least) three bandwidth limited amps that you tell me all sound great and one wide bandwidth amp you use sparingly if at all. You don’t even believe your own experience!

 

[morricab]

Yes, one shouldn’t connect an antenna to the output of an amp that’s able to amplify radio frequencies. That’s intrinsic to its design and not a design flaw.

Greetings from Switzerland, David.

Design flaw if it can oscillate and blow up. An amp should fit its purpose and amplifying radio waves isn’t one of them that I was aware of…the need to have such bandwidth is dubious at best.

 

[morricab]

Why? Because you don’t like it?

Greetings from Switzerland, David.

No, because it measures an awful lot like the amp Hear Here said measured good and sounded bad, which you then said it must measure bad if it sounds bad. Since I am quite sure that it and a Spectral measure objectively quite similarly then the Spectral too by your logic must measure bad.

However, I will object to your attempt to twist to your own meaning what a good measurement for an amp is. Everyone on this forum or who reads magazines that measure know what is meant by this. It is then fine to say that you don’t think the data in those measurements directly correlates with perceived sound quality but it is not ok to try to change the understood definition of a good measurement is.

 

[Hear Here]

If they sound bad, they must measure bad

That may be true but the reverse "If they sound good, they must measure good" is not necessarily so and neither is "If they measure good, they must sound good"

If the only measure of a good amp is its measurements, the designer has little more than a robotic job to reach the goal of a perfect amp.

Any designer worth his salt will build a number of prototypes based on his experience in amp design and will LISTEN to his creations. He'll enlist others with good ears and listen on a number of good speakers. If it sounds great, it is likely to get favourable reviews and will sell well, so who cares about the measurements? Only AVS readers (are they listeners? I don't think so) and it is likely to have pretty good measurements anyway. But buying an amp for its measurements is frankly a bit crazy!

 

[acousticsguru]

I will be blunt then, bandwidth in an amp doesn’t matter much beyond human hearing . Your experience doesn’t even bear that out…you have (at least) three bandwidth limited amps that you tell me all sound great and one wide bandwidth amp you use sparingly if at all. You don’t even believe your own experience!

Sorry I’m not thinking in terms of mutually exclusive absolutes: again, it’s an impression I got over the years that there’s a correlation between bandwidth and impulse response/phase linearity/settling time. And yes, I’ll admit, and always have, that I like different things for different reasons.

Greetings from Switzerland, David.

 

[acousticsguru]

That may be true but the reverse "If they sound good, they must measure good" is not necessarily so and neither is "If they measure good, they must sound good"

If the only measure of a good amp is its measurements, the designer has little more than a robotic job to reach the goal of a perfect amp.

Any designer worth his salt will build a number of prototypes based on his experience and in amp design and will LISTEN to his creations. He'll enlist others with good ears and listen on a number of good speakers. If it sounds great, it is likely to get favourable reviews and who cares about the measurements? Only AVS readers (are they listeners? I don't think so) and it is likely to have pretty good measurements anyway. But buying an amp for its measurements is frankly a bit crazy!

My take on this is we apparently don’t know and currently seem stuck with measurements that at least partly seem irrelevant. Who knows what the future holds?

Greetings from Switzerland, David.

 

[Amir]

1- measurements of ASR forum or Stereophile are the simplified version of non-linear systems

2- mixing two (or more) non-linear systems (like connecting dac to pre) in series could produce more complex non-linear results

3- we also need scientific model of brain/hearing system for defining good vs bad sound but we do not have it

When we have no access to complete mathematic model of systems why we are discussing about good sound by looking at measurements?!

 

[Rensselaer]

Note I’m not saying one can’t use a particularly “tubey” sounding amp (or, DAC, or both) to make e.g. early mono recordings “palatable”.

Ipsofacto; I'm not saying one can't use solid state to make early mono recordings "un-palatable"?

 

[Rensselaer]

That patently doesn't make sense: if it sounds bad but measures well, this only means what's being measured is irrelevant - in other words, it does not measure well.

Greetings from Switzerland, David.

Or, it means that what is measured doesn't seem to correlate with how well users will like its performance.

Some measurements might, like Atmosphere, I believe, agreed that higher order harmonics (measurable) ruin the sound, I agree, especially odd-order.

But this thread was supposed to uncover what topology/design factors we now think does (or doesn't) contribute to the best sounding amplification. It seems to have instead turned into a venue for pontificating on whatever, even semantics: "High Fidelity = Accuracy to the Source" (actually; fidelus = faithful or loyal, high= to a high degree).

What is needed from this highly experienced and knowledgeable group after consultation is some sort of agreement as to what everyone agrees makes the greatest real difference in "audible" outcome.

For instance, I said that, IMHO, over-engineering with loads of electronic processes applied between source and speaker, perhaps to correct "measurements" or to cut costs ( such as using a diodes in place of more expensive rectifier tubes), ruins the sound. I also said, IMHO, that designing a simple circuit with the lowest parts number but with the best parts available usually sounds best. Atmosphere, agreed to the simple design with excellent parts idea, but only as a segue to advertise his own OTL amplifiers.

Can't we show fidelity to the intent of the question (and honest). Just share your best advice for achieving the best sound, cost no bearing?

 

[morricab]

Or, it means that what is measured doesn't seem to correlate with how well users will like its performance.

Some measurements might, like Atmosphere, I believe, agreed that higher order harmonics (measurable) ruin the sound, I agree, especially odd-order.

But this thread was supposed to uncover what topology/design factors we now think does (or doesn't) contribute to the best sounding amplification. It seems to have instead turned into a venue for pontificating on whatever, even semantics: "High Fidelity = Accuracy to the Source" (actually; fidelus = faithful or loyal, high= to a high degree).

What is needed from this highly experienced and knowledgeable group after consultation is some sort of agreement as to what everyone agrees makes the greatest real difference in "audible" outcome.

For instance, I said that, IMHO, over-engineering with loads of electronic processes applied between source and speaker, perhaps to correct "measurements" or to cut costs ( such as using a diodes in place of more expensive rectifier tubes), ruins the sound. I also said, IMHO, that designing a simple circuit with the lowest parts number but with the best parts available usually sounds best. Atmosphere, agreed to the simple design with excellent parts idea, but only as a segue to advertise his own OTL amplifiers.

Can't we show fidelity to the intent of the question (and honest). Just share your best advice for achieving the best sound, cost no bearing?

What topologies are the best sounding amps you have heard?