Do all amplifiers sound the same thread

[Gordonj]

What a minute. So now suddenly it is not worth doing an A/B to see if amps have different sound? I thought that was the whole purpose of this discussion - how can it easily be done and proven, if at all...

 

[3db]

Nah; you can engineer an amplifier to have a sound.

Edit: Also the sections regarding amplifier sounds here are worth a quick read:

Roger Russell's Audio Distortions Truth and Humor

Hell, One can engineer anything but in the truest sense of faithfully amplifying a signal, I think companies strive for just that and not to engineer a particular sound.

 

[mtrycrafts]

I agree, that an amp driven at low volumes and well within their design intent limit, one would be hard pressed to hear a difference. Hence much of the problem associated with home HiFi. In our homes we seldom drive a 250w amp to the point where you will hear its flaws.

I still contend that a $300 receiver will not sound as "good" as a dedicated $3k amp. The components alone will leave a different signature. Further, in the world that I have grown up in and work everyday (commercial performance audio) when driving concert levels with many speakers that are pushing hard you can hear a difference between manufactures and even series/models within a manufactures line. Each amp manufacture treat the sound differently. I know that is not what we are talking about here but because of that heard experience, I tend to the side that all amps will effect the sound differently to some degree - again when pushed.

I cannot speak to commercial amps used for concerts and how they do under DBT conditions as I have not seen any such testing.
But, I can speak about consumer audio amps and what DBTs have shown, even comparing $300 Yamaha integrated amp to Pass Aleph monoblocks where 3 golden ears could not differentiate them, an Internet famous test.

 

[Steve81]

Hell, One can engineer anything but in the truest sense of faithfully amplifying a signal, I think companies strive for just that and not to engineer a particular sound.

Unfortunately what companies should strive for and what they do strive for can be very, very different.

http://theaudiocritic.com/plog/index.php?op=ViewArticle&articleId=29&blogId=1

A shining beacon of how to build an amplifier it is not...

 

[3db]

Personally, I think there are subtle differences in sound between amps, but listening for them in A/B test, or especially a DBT, is very difficult. I also think the amps tested need to be much more different than was the case in the silly testing I described earlier in this thread. Like if I used a $500 AVR rather than just another high quality amp from the same manufacturer. Even so, I'd be unlikely to take any A/B or DBT bets on amps. It's too difficult a problem, and in my experience frustrating more than revealing.

If there are subtle difference, then one would need speakers of high enough calibre to resolve these subtleties plus an acoustically treated room to hear them, aspects that are missing from amplifier tests.

 

[3db]

Unfortunately what companies should strive for and what they do strive for can be very, very different.

http://theaudiocritic.com/plog/index.php?op=ViewArticle&articleId=29&blogId=1

A shining beacon of how to build an amplifier it is not...

One can pick out the exceptions but these aren't the general rule. Do you honestly think there's a trend based on a few bad apples?

 

[mtrycrafts]

If there are subtle difference, then one would need speakers of high enough calibre to resolve these subtleties plus an acoustically treated room to hear them, aspects that are missing from amplifier tests.

I have been thinking about subtle difference and its real importance

If it takes a super setup in a super quiet room and a DBT with 20+ trials just to be barely statistically significant, why does it really matter? Do audiophiles, especially "golden ear" fame listen for that subtlety for hours to find them? When do they listen to the music for enjoyment???

I for one don't have that luxury.

 

[Steve81]

One can pick out the exceptions but these aren't the general rule. Do you honestly think there's a trend based on a few bad apples?

Depends on the market segment/niche. In general, I'd trust an Onkyo, Denon, Marantz, Yamaha, Emotiva, etc to test well into an 8 ohm resistor. A Conrad Johnson tube amp? I'm less confident.

 

[3db]

Depends on the market segment/niche. In general, I'd trust an Onkyo, Denon, Marantz, Yamaha, Emotiva, etc to test well into an 8 ohm resistor. A Conrad Johnson tube amp? I'm less confident.

Yikes I forgot to stipulate....sticking with solid state amps...although, I would like to hear a tube amp to see what the fuss is all about.

 

[Steve81]

So now suddenly it is not worth doing an A/B to see if amps have different sound?

Depends on what you're trying to prove, and how useful this information is.

I mean I get it: at some point when you make things easy enough, the vast majority of amplifiers should sound nigh indistinguishable from one another. I'd like to think there isn't anything groundbreaking about this information, but I guess if you're a hardcore subscriber to Stereophile, this might be news.

OTOH, by making things so easy, you're also making the test less useful in the real world. What good is it to know that two amplifiers will sound the same under some reasonably ideal load and low drive levels if you're not actually going to use them in such a manner?

 

[3db]

Depends on what you're trying to prove, and how useful this information is.

I mean I get it: at some point when you make things easy enough, the vast majority of amplifiers should sound nigh indistinguishable from one another. I'd like to think there isn't anything groundbreaking about this information, but I guess if you're a hardcore subscriber to Stereophile, this might be news.

OTOH, by making things so easy, you're also making the test less useful in the real world. What good is it to know that two amplifiers will sound the same under some reasonably ideal load and low drive levels if you're not actually going to use them in such a manner?

There many speakers outhere including the Pioneers that would be easy enough to drive where amps would not distinguish themselves.

 

[Steve81]

There many speakers outhere including the Pioneers that would be easy enough to drive where amps would not distinguish themselves.

Interesting statement for a couple of reasons:

1. We don't know what load the Pioneers actually represent at this point. Of course it's worth pointing out that Gene seems to think they might not be the easiest speakers in the world to drive, and I'd tend to trust his judgement.

2. I'd expect I can drive a bottom of the barrel Sony receiver to the point of distinguishing itself from a UPA-500, even on a set of Pioneers.

 

[3db]

Interesting statement for a couple of reasons:
2. I'd expect I can drive a bottom of the barrel Sony receiver to the point of distinguishing itself from a UPA-500, even on a set of Pioneers.

And your point is what exactly since you invalidated one of the conditions?

 

[Steve81]

And your point is what exactly since you invalidated one of the conditions?

People aren't limiting their conditions in the real world, so your test has limited utility.

 

[Steve81]

People aren't limiting their conditions in the real world, so your test has limited utility.

To put it another way, what do I care if a bottom of the barrel Sony sounds the same as an Emo UPA-500 at -30dB from reference on my system if I prefer to listen around -15dB from reference and occasionally push the volume up to -5dB from reference?

 

[Irvrobinson]

If there are subtle difference, then one would need speakers of high enough calibre to resolve these subtleties plus an acoustically treated room to hear them, aspects that are missing from amplifier tests.

I've always thought that there were several kinds of differences:

1. Differences that are inaudible. (Got that out of the way.)

2. Differences that are audible, but innocuous. Like frequency response being down 2db at 18KHz. To some people it will be audible, but it probably only on test tones. Some differences will not lead a person to think the amp is inferior. A bit of second or third harmonic distortion may fall into this category. In fact, some people may like it.

3. Differences that are audible and overt. Like old-fashioned clipping.

4. Differences that are audible but not overt. I think these differences contribute to listener fatigue, but may not be easily perceivable at any given time. I'd put IM distortion in this category, as well as compression (like from input stage overload), or perhaps a noise floor that is really non-linear in its frequency distribution. I'm not so sure super speakers or super rooms are required to perceive these differences.

I think class 2 and 3 distortions mostly don't exist in well-designed solid-state amps. I think people like me who believe there are some audible differences between amps are talking about class 4 distortions in my list, and they annoy you over time. I think this could be why it is so difficult to do even a simple A/B test with amps and reveal repeatable preferences, yet some of us perceive them. Or on the other hand class 4 differences are really class 1 differences, and people like me are deluding themselves.

 

[walter duque]

I am in and out of this thread. I have owned a few power amps over the past 40+ years ( I would say a about 100+) and none of the them sounded the same. Not one. Everyone had it's own sound.

 

[PENG]

My space is a lot larger than yours, and my speakers 3db less sensitive than your Energy speakers, but as I already posted, on some material *I know* can hear the power difference. Of course, I was measuring 102db+ peaks when I heard it. Probably 90db average volume level at my listening position. I probably couldn't hear differences on a Diana Krall album either (I have every one). Try fusion jazz for a better test.

I picked Diana Krall because her kind of jazz CDs don't have much DR, about 12 dB I guess, so it is very easy to see the average SPL even without measurement instruments. The use of a digital Hioki meter was just to confirm my not so reliable visual judgment.

When I measure peaks I prefer to use classical music. In the past I have seen peaks >20W even with my more sensitive KEF and Focal speakers playing classical music disc that I know has high DRs.

My quick measurement session was done to demo one can listen to average SPL of 85 dB with peaks >90dB when the amp is outputting 1W or less and less than 0.5A with peaks no greater than 10W. That's RMS current, so for peaks it could be much higher depending on the waveform but would still be under 1A in any case. Still, it just shows that while I believe in more power the better, it isn't true to think most people are actually hearing day and night kind of difference as soon as they swap out their mid range AVR such as a Yamaha RXV-2010's internal amp with a 200WPC power amp. Hence my feeling that people often exaggerate the effect of adding an external amp on sound quality, and I guess that could be understandable, given what they have been told prior, anticipating and having spent the money.

 

[PENG]

Here's the sad part for me:

In spite of all this, I still want a separate amplifier; and you know, if I do get one, I'm sure I'll hear a night and day difference too

Same here, currently I am using 3 power amps with a total about 2kW (not counting the power of the amps in 4 subs) in my 7.1 H.T. system, when my Denon 4308 used to drive them all just the same. I also never really needed big 4WD V8 SUVs yet I have had a few up to a few years ago when I finally understood I was only wasting gas and leaving the 4 wheel drive systems to age without being ever put to use.

 

[PENG]

Interesting statement for a couple of reasons:

1. We don't know what load the Pioneers actually represent at this point. Of course it's worth pointing out that Gene seems to think they might not be the easiest speakers in the world to drive, and I'd tend to trust his judgement.

2. I'd expect I can drive a bottom of the barrel Sony receiver to the point of distinguishing itself from a UPA-500, even on a set of Pioneers.

I trust Gene too on the easy/hard to drive issue but I would say that's mostly moot points. The thing is, if one is listening at lower avg SPL, say below 80dB in a THX standard medium size room because one would be using less than one watt most of the time with peaks to perhaps 10W, and that's with speakers as easy to drive as a pair of R900. So if those Pioneer are harder to drive, okay how about double my numbers, so one would need a couple of watts average with occasional needs of 20W or slightly more, most Onkyo, Denon, Yamaha, Marantz AVRs within the price group of $1500 to $2500 could sound like the more powerful Emo XPA-5 in theory and should, in practice as well.

Bottom line, I tend to agree with 3 dB on this.