Which of these amps would sound best

[Keith_W]

You know everytime i read an answer like this, there are 10 times more people out there that says things like "some amps sound more musical, richer, warmer, and musical Cleaner, more precise sound (thanks to lower THD)

You are right. We are a pretty small minority in this hobby. The vast majority of audiophiles think that amplifiers sound different. They are right, too - amplifiers can and do sound different. Listen to what Erin has to say about it:

Without getting too technical, some poorly designed amplifiers will change the frequency response depending on speaker impedance. Speaker impedance varies according to frequency, but also varies depending on volume and how much the voice coil and crossover components have heated up. So an amplifier that sounds "warm" on one speaker may not interact with another speaker the same way.

The bigger question is, why would you want that in the first place? Everything else - "warmth" or "richness" or what have you - is an addition created by the amplifier, that was not in the recording.

The reason why ASR is different is because we look at why some amplifiers perform differently with different speakers. We don't give subjective impressions, we look at data. Some of us with suitable equipment are able to test amplifiers. Being able to interpret the data is something else, though ... and IMO it's too much to ask a newcomer to learn how to look at those graphs and understand what it's telling you.

As long as the amplifier is in its linear range, has sufficiently low output impedance, and does not suffer from problems such as excessive noise or harmonic distortion - they will all sound the same. So the simplest advice to give is: get a well designed amplifier, make sure it has enough output power for your application (and thus keeping it within its linear range), and be done with it.

 

[DanielT]

ok i was getting to this......things happened too quickly to "document" i ended up buying a NAD T750, the guy sold it paired with some AR speakers and i asked if i could just buy the amp only, usually people say no, but this guy said yes, i looked at the specs from this amp and it looks like exactly what i need for my 4 ohm speakers, and room to upgrade the speakers, i do like nads having had one in the past. Also its from 2007 so not stone ancient at all...if it works without issues i will be super happy.

i will post how it goes, and i will need help setting it up, but first i need to get those tweeters, i'm about to put in a money back claim tomorrow if it doesn't arrive...sigh... thank you all for the help so far.

Aha, congratulations on that amplifier. It will work well with your speakers.

thanks, useful info

Dynamics in music. The lack, or reduction of it in music is usually called loudness war. If you are interested, you can read about it here:

Loudness war - Wikipedia

en.wikipedia.org

The video below. Compressed music, simply does not require much amp power/power headroom. But it can be quite boring to listen to. The example with more dynamics, more fun to listen to but the (red) peaks make more demands on amp power, especially if you are going to play at higher volume:

 

[krabapple]

You know everytime i read an answer like this, there are 10 times more people out there that says things like "some amps sound more musical, richer, warmer, and musical Cleaner, more precise sound (thanks to lower THD).

Yes, and...? Does the quality of information matter to you, or just the quantity?

It just goes on and on so though i read your reply, there is just endless of people stating what i just mentioned. and some expressively saying that the different amps they owned sounded different, it sounded like even equing them could not get them to match.

And there are even more endless of people -- all of us, really -- who are subject to perceptual biases that account for those expressive reports.

Look up this video that Amir, the host of this very website, made about comparing audio devices properly

 

[Roland68]

You know everytime i read an answer like this, there are 10 times more people out there that says things like "some amps sound more musical, richer, warmer, and musical Cleaner, more precise sound (thanks to lower THD).

Warm, precise analog performance

Clean, flexible though more electronic

Every circuit is tuned to deliver clean, coherent, and natural sound
classic Linear A design produces smooth mids, natural highs, and controlled bass.
Instruments and vocals are more engaging than on typical AVRs, which can sound colder or more clinical.

High damping factor on amps keeps bass precise, even with big speakers.
Music sounds full and controlled, not bloated or loose.


Some say some amps have better midrange capability, richer sound, and detail differences.
etc...etc....etccc

It just goes on and on so though i read your reply, there is just endless of people stating what i just mentioned. and some expressively saying that the different amps they owned sounded different, it sounded like even equing them could not get them to match.

And exactly these people you're talking about, the ten times more, suddenly can't distinguish which device or amplifier is running in a real blinded test, even though they've heard huge differences before.
I've been dealing with such topics for over 35 years and have experienced exactly this countless times in such demonstrations. For a while, I was even banned from such events because blinded listening would ruin such events, and I always insisted on it.

Most of these people don't understand one thing: the music data, whether analog or digital, leaves no room for interpretation during playback; it's very precise data that doesn't change. Any deviation from this is initially a defect in the device, or faulty playback.
There are certainly manufacturers who have sounded their devices, but this is a very uncontrolled intervention in the data, and this can be done much better and more cleanly with a DSP.

So you have to ask yourself whether you really want to hear what was recorded, or an uncontrolled change in the music, which can have a different effect on each piece.

 

[witwald]

anyway ! the long grind is finally over (touch wood if it works without hassle not tested it yet) i bought an amp now for the wait to see if my tweeters arrive for my speakers from ebay quite stressed about this one...

Hmmm...it's unfortunate that blown tweeters can often be the result of driving low-powered amplifiers into clipping during louder listening sessions. Please don't ask me how I know... Still, 50W/channel should give some safety margin over 35W/channel.

 

[kevinsonic]

You are right. We are a pretty small minority in this hobby. The vast majority of audiophiles think that amplifiers sound different. They are right, too - amplifiers can and do sound different. Listen to what Erin has to say about it:

Without getting too technical, some poorly designed amplifiers will change the frequency response depending on speaker impedance. Speaker impedance varies according to frequency, but also varies depending on volume and how much the voice coil and crossover components have heated up. So an amplifier that sounds "warm" on one speaker may not interact with another speaker the same way.

The bigger question is, why would you want that in the first place? Everything else - "warmth" or "richness" or what have you - is an addition created by the amplifier, that was not in the recording.

The reason why ASR is different is because we look at why some amplifiers perform differently with different speakers. We don't give subjective impressions, we look at data. Some of us with suitable equipment are able to test amplifiers. Being able to interpret the data is something else, though ... and IMO it's too much to ask a newcomer to learn how to look at those graphs and understand what it's telling you.

As long as the amplifier is in its linear range, has sufficiently low output impedance, and does not suffer from problems such as excessive noise or harmonic distortion - they will all sound the same. So the simplest advice to give is: get a well designed amplifier, make sure it has enough output power for your application (and thus keeping it within its linear range), and be done with it.

Wow this is an eye opener, i have listened to the whole lecture He is using some what i will call high end pieces there and everything makes sense. For me the practical use information for my case scenario came at14:04, and thank goodness i think i made the right choice, (given if the amp works without issues) Thank you so much for this very interesting talk.

I was beginning to think certain amp models, defaulted their systems from factory to sound in a specific way they want it to sound, but it seems like matching impedance with speaker impedance and crossovers is everything.

 

[kevinsonic]

Aha, congratulations on that amplifier. It will work well with your speakers.

Dynamics in music. The lack, or reduction of it in music is usually called loudness war. If you are interested, you can read about it here:

Loudness war - Wikipedia

en.wikipedia.org

The video below. Compressed music, simply does not require much amp power/power headroom. But it can be quite boring to listen to. The example with more dynamics, more fun to listen to but the (red) peaks make more demands on amp power, especially if you are going to play at higher volume:

Thanks, i hope all is well with the amp havent had time to test yet, the YT you gave, interesting, i'm taking a few more listen throughs.

 

[kevinsonic]

Yes, and...? Does the quality of information matter to you, or just the quantity?


And there are even more endless of people -- all of us, really -- who are subject to perceptual biases that account for those expressive reports.

Look up this video that Amir, the host of this very website, made about comparing audio devices properly

The above video from Keith was an eye opener, i'm sure this will be a complementary follow up, thanks most definately going to watch it tonight when i'm at home, out of time right now.

 

[kevinsonic]

And exactly these people you're talking about, the ten times more, suddenly can't distinguish which device or amplifier is running in a real blinded test, even though they've heard huge differences before.
I've been dealing with such topics for over 35 years and have experienced exactly this countless times in such demonstrations. For a while, I was even banned from such events because blinded listening would ruin such events, and I always insisted on it.

Most of these people don't understand one thing: the music data, whether analog or digital, leaves no room for interpretation during playback; it's very precise data that doesn't change. Any deviation from this is initially a defect in the device, or faulty playback.
There are certainly manufacturers who have sounded their devices, but this is a very uncontrolled intervention in the data, and this can be done much better and more cleanly with a DSP.

So you have to ask yourself whether you really want to hear what was recorded, or an uncontrolled change in the music, which can have a different effect on each piece.

People like you needs to control the PR of the marketing industry.

 

[kevinsonic]

Hmmm...it's unfortunate that blown tweeters can often be the result of driving low-powered amplifiers into clipping during louder listening sessions. Please don't ask me how I know... Still, 50W/channel should give some safety margin over 35W/channel.

Thanks my speakers are rated 80 watt peak, the T750 should hopefully give around 89 watts at 4 ohms in stereo mode, minus some because of age perhaps too i guess, but still should be plenty good i feel if the amp is in good shape. I will be posting a new thread wrt my speakers when i get my tweeters, but no sign of them yet

 

[Keith_W]

Thank you so much for this very interesting talk.

Don't thank me, thank Erin! And FWIW there is a lot more that Erin didn't cover that makes amps sound different, for e.g. valve amplifiers can have variable group delay thanks to transformers, other nonlinearities due to valves being out of tolerance, etc. etc. All this is real, and can be heard. But none of this is desirable. Typical audiophiles turn flaws into virtues, and virtues into flaws. Give them a perfect amplifier and they will complain it sounds "sterile".

When Dr. Toole was asked in a discussion about the GedLee metric (a new metric for quantifying amplifier distortion by applying different weighting to different harmonics), he replied that the only consistently acceptable amount of distortion is zero.

Subjectivists spend years and thousands of dollars without understanding why some amps don't perform like the reviews said, or trying to correct a tonally flawed loudspeaker by finding a tonally flawed amp for it.

 

[kevinsonic]

Don't thank me, thank Erin! And FWIW there is a lot more that Erin didn't cover that makes amps sound different, for e.g. valve amplifiers can have variable group delay thanks to transformers, other nonlinearities due to valves being out of tolerance, etc. etc. All this is real, and can be heard. But none of this is desirable. Typical audiophiles turn flaws into virtues, and virtues into flaws. Give them a perfect amplifier and they will complain it sounds "sterile".

When Dr. Toole was asked in a discussion about the GedLee metric (a new metric for quantifying amplifier distortion by applying different weighting to different harmonics), he replied that the only consistently acceptable amount of distortion is zero.

Subjectivists spend years and thousands of dollars without understanding why some amps don't perform like the reviews said, or trying to correct a tonally flawed loudspeaker by finding a tonally flawed amp for it.

Well my eyes have been opened, i still need to get as grasp on what's been said but i'm about 80% there. Minus the very many years of experience and expertise of you people.
This is truly a great forum.

Finally i have a better understanding and hopefully now i can customize my amp to the sound i'm after.

 

[DanielT]

No need to mix in a really expensive tube amp just to (possibly) color the sound. IF Kevin wants to do that, consciously color, change the sound that is, then he can add in a distortion plugin, for example this one:

PKHarmonic VST Plugin - Audiophile Harmonics Generator | Distort documentation

PKHarmonic 1.0 is the initial release of this software. Use at your own risk!

distortaudio.org

... that VST Plugin plus EQ.

Together with his NAD T750 amp. Then Kevin can add as much distortion and create as crazy FR via EQ as he wants. That would make any expensive tube amp turn green with envy.

Or Kevin leaves his NAD T750 as it is and lets it amplify the signal without distorting it, and /or changing the FR.

ON THE OTHER HAND EQ in the lower bass range, where the room acoustics have a big impact, is really recommended but that's more of a topic for another thread (there are many of those on ASR that address that topic).

Plus, regarding EQ. If you play at low volume, a little extra boost in the lower and higher frequency registers can be nice to have, so-called Fletcher-Munson loudness compensation. A matter of taste if you like it. Also OT for this thread. Better to bring it up and discuss it here:

'Should you use Fletcher-Munson loudness compensation?'

Jan 2, 2022

I know many are familiar with the Fletcher-Munson or equal loudness curves. In a nutshell:

“The Fletcher Munson Curve contains a set of graphs that show that when you listen to music at a lower volume, mid-range frequencies will be sound more prominent, whereas high and low frequencies will be somewhat suppressed.

However, when the volume is increased, the reverse happens – high and low frequencies become more pronounced while the mid-range frequencies fade into the background.

In other words, the Fletcher Munson Curve demonstrates the average sensitivity of a human ear to...

• dshreter
• Replies: 220
• Forum: Psychoacoustics: Science of How We Hear

• 

 

[DSJR]

You know everytime i read an answer like this, there are 10 times more people out there that says things like "some amps sound more musical, richer, warmer, and musical Cleaner, more precise sound (thanks to lower THD).

Warm, precise analog performance

Clean, flexible though more electronic

Every circuit is tuned to deliver clean, coherent, and natural sound
classic Linear A design produces smooth mids, natural highs, and controlled bass.
Instruments and vocals are more engaging than on typical AVRs, which can sound colder or more clinical.

High damping factor on amps keeps bass precise, even with big speakers.
Music sounds full and controlled, not bloated or loose.


Some say some amps have better midrange capability, richer sound, and detail differences.
etc...etc....etccc

It just goes on and on so though i read your reply, there is just endless of people stating what i just mentioned. and some expressively saying that the different amps they owned sounded different, it sounded like even equing them could not get them to match.

PLEASE, there will be as many * audio subjectivist* opinions out there as regards different sounding amps, as there are audio subjectivists!

Why?

Because we subjectively judge music and the gear to reproduce it WITH ALL OUR SENSES, not just our ears or hearing acuity, which in the animal kingdom are actually rather poor I gather! I was taught decades back that our brain processing gives around 70% to visuals (would @Kal Rubinson please help or put me to right here) and believe me on a practical basis selling the stuff, visuals and a 'tactile feel' really count for a lot here in product choice, as well as the price tag for many too.

When I've not been thinking about it and remembering a recent short music session I had here when the need for music over-rode anything else, I had a wonderful session of tunes, some mid bass impact, foot-tapping rhythms and a good sense of 3-D in the contemporary music I played - mostly digital but I did play the record player a little bit too, this through a preamp I thought was a bit 'lean' from old experience and a vintage pro MOS-FET power power amp I'd convinced myself didn't 'do' air and space that well. It bloody did that lunchtime, purely because I wasn't giving any thought at all, to the tools to reproduce the music (oh alright, the sound system).

As I said before, I knew, liked and sold a good few PMA 450SE amps in the late 90s, which on the bench, offered good power output and I recall a clean tidy basic performance, a reliable build and a fit-and-forget kind of aura, able to drive many of the popular speakers of the times. I'm sure the other amps you mention would do it too.

I also remember not at all liking the Sansui AUD range of amps when we had them. Nothing like the previous well-loved range, but I'm harking back nigh-on fifty years now and as with all *subjective* memories, these can cheat as our brains don't always store said memories literally.

HiFi Choice amp book in 1981, tested the AUD5. It didn't come out that well, possibly on niggly things as vinyl was the main source back then. It didn't get 'recommended' (issue should be in 'worldradiohistory' so you can look it up for yourself. Later Sansui amps returned to the recommended lists, however. Models were changing almost by the season and I couldn't keep up with it all.

I don't know the PM53 amp, but would hope that it's an entirely competent amp at least and from a later era than the other two amps above, so hopefully plenty of life left.

P.S. I see the op has bought an amp. I hope they have plenty of music sessions using it

 

[AaronJ]

One of ASR’s missions is to protect against misinformation, and AI falls into that category.

 

[kevinsonic]

No need to mix in a really expensive tube amp just to (possibly) color the sound. IF Kevin wants to do that, consciously color, change the sound that is, then he can add in a distortion plugin, for example this one:

PKHarmonic VST Plugin - Audiophile Harmonics Generator | Distort documentation

PKHarmonic 1.0 is the initial release of this software. Use at your own risk!

distortaudio.org

... that VST Plugin plus EQ.

Together with his NAD T750 amp. Then Kevin can add as much distortion and create as crazy FR via EQ as he wants. That would make any expensive tube amp turn green with envy.

Or Kevin leaves his NAD T750 as it is and lets it amplify the signal without distorting it, and /or changing the FR.

ON THE OTHER HAND EQ in the lower bass range, where the room acoustics have a big impact, is really recommended but that's more of a topic for another thread (there are many of those on ASR that address that topic).

Plus, regarding EQ. If you play at low volume, a little extra boost in the lower and higher frequency registers can be nice to have, so-called Fletcher-Munson loudness compensation. A matter of taste if you like it. Also OT for this thread. Better to bring it up and discuss it here:

'Should you use Fletcher-Munson loudness compensation?'

Jan 2, 2022

I know many are familiar with the Fletcher-Munson or equal loudness curves. In a nutshell:

“The Fletcher Munson Curve contains a set of graphs that show that when you listen to music at a lower volume, mid-range frequencies will be sound more prominent, whereas high and low frequencies will be somewhat suppressed.

However, when the volume is increased, the reverse happens – high and low frequencies become more pronounced while the mid-range frequencies fade into the background.

In other words, the Fletcher Munson Curve demonstrates the average sensitivity of a human ear to...

• dshreter
• Replies: 220
• Forum: Psychoacoustics: Science of How We Hear

• 

That is some extra tweaking options i had not known about, thanks, i foresee me having some questions wrt this once i set it all up, i'm still waiting for my tweeters but am going to start my speaker thread solong.

 

[kevinsonic]

PLEASE, there will be as many * audio subjectivist* opinions out there as regards different sounding amps, as there are audio subjectivists!

Why?

Because we subjectively judge music and the gear to reproduce it WITH ALL OUR SENSES, not just our ears or hearing acuity, which in the animal kingdom are actually rather poor I gather! I was taught decades back that our brain processing gives around 70% to visuals (would @Kal Rubinson please help or put me to right here) and believe me on a practical basis selling the stuff, visuals and a 'tactile feel' really count for a lot here in product choice, as well as the price tag for many too.

When I've not been thinking about it and remembering a recent short music session I had here when the need for music over-rode anything else, I had a wonderful session of tunes, some mid bass impact, foot-tapping rhythms and a good sense of 3-D in the contemporary music I played - mostly digital but I did play the record player a little bit too, this through a preamp I thought was a bit 'lean' from old experience and a vintage pro MOS-FET power power amp I'd convinced myself didn't 'do' air and space that well. It bloody did that lunchtime, purely because I wasn't giving any thought at all, to the tools to reproduce the music (oh alright, the sound system).

As I said before, I knew, liked and sold a good few PMA 450SE amps in the late 90s, which on the bench, offered good power output and I recall a clean tidy basic performance, a reliable build and a fit-and-forget kind of aura, able to drive many of the popular speakers of the times. I'm sure the other amps you mention would do it too.

I also remember not at all liking the Sansui AUD range of amps when we had them. Nothing like the previous well-loved range, but I'm harking back nigh-on fifty years now and as with all *subjective* memories, these can cheat as our brains don't always store said memories literally.

HiFi Choice amp book in 1981, tested the AUD5. It didn't come out that well, possibly on niggly things as vinyl was the main source back then. It didn't get 'recommended' (issue should be in 'worldradiohistory' so you can look it up for yourself. Later Sansui amps returned to the recommended lists, however. Models were changing almost by the season and I couldn't keep up with it all.

I don't know the PM53 amp, but would hope that it's an entirely competent amp at least and from a later era than the other two amps above, so hopefully plenty of life left.

P.S. I see the op has bought an amp. I hope they have plenty of music sessions using it

Yes, did get an amp the grind is finally over Thanks. interesting about the au series you mention, i suppose opinions run deeper than an few forum searches and an ai search.
At one stage before getting the nad amp i was wondering if i should just use my 1994 camtec CA-504 100 watt x 4 car amp. and eq it. i strongly considered it.