My Faith In AH Has Been Restored (I was really starting to wonder)

[<eargiant]

I wish I would have come across this before I requested that the other thread be closed. This article restored my faith in this place. Hopefully it will enlighten some of the misguided members on the other thread that were so sure of themselves and vocal enough to derail the conversation with their ill-informed comments. I thought this article might provide some of the objective rationale they were looking for, especially since it is not coming from me.

While the other thread was supposed to focus on the effects of design choices, signal path, etc. it led to a lot of topics that were vigorously and heatedly debated, which is a good thing, but we hit an impasse because many disagreed with pretty much anything I said. Some of those same topics are addressed in this article by engineers that are WAY more qualified than anyone else on that other thread. Much of it also coincides with what I was saying.

I actually think that my thinking is more in line with Gene's than it is with many of the most vocal members of this forum. At times on that other thread I couldn't help but think, does Gene actually believe what these guys are saying? Has this site gone off the deep end? I mean, it was started by an engineer for goodness' sake.

I can't really say I disagree with anything Gene says here or what's written in the article but based on my experience I wouldn't be surprised if many of the individuals on that other thread will disagree and roast and ridicule Gene and the late Julian Hirsch's observations and methodologies.

I'm not looking to re-hash this again and I probably will not even post anything else on this thread. It's a great article and video so I posted it to bring it to the attention of some vocal members that might learn something in case they missed it. You know who you are.

http://www.audioholics.com/audio-amplifier/the-sound-of-an-amplifier

Excerpts:

“So here’s the problem, the people that believe all amplifiers sound the same, it’s usually the people that don’t have a lot of experience designing first of all, it’s the people that may look at textbook and say well the ideal amplifier should have zero output impedance, infinite input impedance, no distortion, no noise – well, show me one, show me the money because I haven’t seen it.”

"You know the argument, in all honesty there's people out there that as long as you don't drive an amplifier past it's linearity, they'll all sound the same. Well, my return to that is to say how do you know whether or not you're driving the amplifier beyond it's linearity? Because amplifier tests are done into a resistive load using a sine wave sweep- OK. Those are very know quantities, very controlled quantities. Well, when you're dealing with a real loudspeaker, a loudspeaker is not a resistor, it's an impedance, it has complex impedance that changes with frequency and some speakers are harder to drive than others."

“If I may give you some anecdotal experiences based on listening tests we have done, many amplifier listening tests we’ve done blind for the people that love blind tests, we’ve done them sighted – sighted meaning you could see the amp but you really couldn’t tell which amp was playing, and we found some interesting results. You know, we’ve had- even at normal levels… and people have been able to identify preferences, you know mostly in the bass range. It’s pretty amazing and there’s been times where I couldn’t really explain it, I measured the amplifiers and they both were high power amplifiers- maybe the amplifier that people preferred had a little bit lower output impedance, maybe it had a little bit lower distortion. So you know it’s hard to say, it’s hard to quantify at what level distortion is audible, how low the output impedance needs to be because it really depends on the interaction of the components. “

“I’ve been testing amplifiers for 15 years and I’m quite surprised that they don’t always bench the way they sound.”

“I’m all about overdesigning rather than trying to design to be the cheapest or design to be the minimum best. I don’t believe in the singularly good minimal best nonsense”

“We’ve measured 8 ohm speakers that have a dip at 2 ohms in the low bass range or even in the upper bass range, what does that do to an amplifier? That sucks life out of amplifiers that don’t have adequate power supplies or adequate output capability from the transistors. So you get a speaker that’s moderately efficient with low impedance with various impedance dips and peaks and if the amplifier itself…has high output impedance or it’s not extremely low output impedance then that can change the frequency response and change the sound”

-Gene DellaSala


Now, from the article a little about Julian Hirsch who for decades has been incorrectly labeled as the father of the - "All Amps Sound The Same" ideology.


“After exhaustive testing of several amplifiers with several different speakers (some known to be “easy” loads and some known to be “difficult” to drive), Hirsch made some interesting observations that simultaneously explained why there were potential sound differences between amplifiers while at the same time remaining utterly faithful to the quantifiable, repeatable scientific process. It remains, in my view, the best explanation for this entire topic that I have yet seen.

Starting with the huge and all-important assumption that the amplifier under test is not being driven into distortion or being operated in a way that could elicit bad behavior, overheating, or engage any protection circuitry, Hirsch found the following:

• Some pre-amp/power amplifier/speaker systems combined in such a way as to produce a very slightly rising or drooping frequency response across the entire 20-20 kHz audible spectrum. It could be a combination of the way the pre-amp and power amp combined on an input/output impedance basis, it could be because of the way a particular amp behaved with the specific load presented by that specific make/model of speaker, but there were system combinations where the frequency response showed a variation across the band.

These were not big variations. Perhaps on the order of + 0.5 dB in the bass to - 0.5 dB in the treble. A 1 dB total tilt, +/-. But over a wide range of frequencies—many octaves—that’s definitely audible. As a matter of fact, this phenomenon is formally known in audio engineering circles as “spectral tilt.” If system “A” is tilted up a dB across the band and system “B” is titled down a dB across the band, experienced listeners will definitely hear that, without question. Godehard Guenther, head of ADS Speakers in the 1970s, talked at length about this effect when voicing his then-top-of-the-line ADS 910 speaker. Extremely slight changes to the speaker’s “tilt” made a dramatic difference in its perceived bass-treble balance and “weight.” Therefore, depending on the program material being used, the interaction of the different components, etc, such a spectral tilt variation could unquestionably lead a listener or reviewer to characterize the amplifier’s sound as “harsh” or “sweet” or “musical,” etc.

• Hirsch also found that small—minute, even—differences in amps’ comparative signal-to-noise ratios often had a tangible impact on their perceived sound.

The SNR difference was not audible as hiss per se. But he did find that a few extra dB of noise could subliminally mix with the program material and lend a very slightly “brighter” or “harder” character to the sound. Granted if amplifier “A” had a SNR ratio of 80 dB and amplifier “B” was 75 dB, both would be considered more than “quiet” enough for high fidelity purposes. But the difference between their SNRs could show up as a perceived difference in tonal character.”

 

[panteragstk]

I have to ask, if you wanted the other thread closed due to debate and it being "heated" then why start another that WILL become the same?

My opinion (and I was an EE major in college so I have a decent understanding) of amps is that if you get two amps that are rated at the same output power. Same THD. Same class. Same dampening factor and anything else you want to name then they should sound the same.

It is ABSOLUTELY possible for them not to given a very specific set of criteria. If a the both are great at 8 ohm loads but one falters at 4 ohm loads then guess which one will sound better? It isn't that amps sound different, it's that in certain situations they can struggle with certain loads.

If an amp sounds different it is either intentionally done by the designer, or it is not working properly given the speaker that it is driving.

I know I'm over simplifying things, but hopefully someone with more knowledge than me and that can more eloquently explain what I mean will chime in.

Amps should be transparent. If they aren't, then they aren't doing their job.

I'm not saying you're wrong, but you aren't right either. People tend to oversimplify this topic.

 

[AcuDefTechGuy]

Many of us care about measurements and theories.

But if these "improvements" in measurements and designs don't improve our actual audible experience, many of us couldn't care less at the end of the day.

AH members should like amps, and many of us have owned many different components over the years (DAC, Amps, Preamps, Pre-pros, Sound Cards, CD players, etc.).

It doesn't hurt to have a thread dedicated to talking ONLY about the theories and measurements (SNR, Crosstalk, THD, FR, Fully-balanced designs, other designs).

So go for it.

The theory is that over-engineered components should have better measurements, better sound quality, and better reliability.

It sounds like a good theory.

 

[Pogre]

I have to ask, if you wanted the other thread closed due to debate and it being "heated" then why start another that WILL become the same?

My opinion (and I was an EE major in college so I have a decent understanding) of amps is that if you get two amps that are rated at the same output power. Same THD. Same class. Same dampening factor and anything else you want to name then they should sound the same.

It is ABSOLUTELY possible for them not to given a very specific set of criteria. If a the both are great at 8 ohm loads but one falters at 4 ohm loads then guess which one will sound better? It isn't that amps sound different, it's that in certain situations they can struggle with certain loads.

If an amp sounds different it is either intentionally done by the designer, or it is not working properly given the speaker that it is driving.

I know I'm over simplifying things, but hopefully someone with more knowledge than me and that can more eloquently explain what I mean will chime in.

Amps should be transparent. If they aren't, then they aren't doing their job.

I'm not saying you're wrong, but you aren't right either. People tend to oversimplify this topic.

Agreed. Not really appreciating the condescending tone of the op either.

@<eargiant, if you could tone down the attitude a little this could actually go somewhere. As it is, this thread is doomed to the same fate. You can communicate your thoughts without insulting people if you try.

 

[sharkman]

The very reason I rarely visit this forum anymore is specifically because of the vitriol of the amps-sound-the-same camp. And look at those of you here now, licking your chops for another debate.

And that's probably a big reason why this forum is a shell of its former self. But debate on champs, beat that dead horse into the ground one more time.

 

[Mikado463]

Julian Hirsch lives !! ............

 

[lovinthehd]

Meh. Still reading lots of maybe and could be and not sure why; not a lot of anything definitive to go shopping with. If you want to spend the time getting "synergy" between your components in this fashion and have the time and money I say go for it! Comparing such things is a royal pain, too. I don't find it worthwhile after owning quite a few components and interchanging them...guess you'll have to call me un"englightened", "misguided" etc....just not a butt clencher for the electronics myself.

 

[mtrycrafts]

...

It sounds like a good theory.

Well, certainly not a scientific theory.
That would take empirical evidence backed by bias controlled, statistically significant listening tests.
And, no, it would be conducted in home listening environments nas Tom Nousaine used to do.

 

[mtrycrafts]

The very reason I rarely visit this forum anymore is specifically because of the vitriol of the amps-sound-the-same camp. And look at those of you here now, licking your chops for another debate.

And that's probably a big reason why this forum is a shell of its former self. But debate on champs, beat that dead horse into the ground one more time.

What? You don't like debates? Just an agreement to what you think it should be? No questioning?

Obviously it is not a dead horse, some think they hear things. Yet, not interested in really finding the answer.
Yes, the answer may be embarrassing to some.

 

[AcuDefTechGuy]

1) Not all amps sound the SAME. Some amps have different voltage gains and not all amps are high quality amps. Some amps can't even handle 4 Ohms, much less 2 ohms, before going into protection mode.

2) All High quality amps sound great.

So I think the only real debate is, which amps are HIGH QUALITY?

Amps with enough power output that can handle 4 ohms with low THD and good SNR?

If my speakers dip down to 2 ohms, I sure would rather have a 60WPC high quality amp that can handle 2 ohms with low THD and good SNR than a 120WPC amp that goes into protection mode at 4 ohms.

 

[equate]

I've owned many receivers and expensive audiophile separates. I currently have a 'middle of the price range' name brand AVR and it sounds great. I have no reason to go back to my old audiophile mind set. These days, I'm very happy that I no longer have to worry about spending a large amount of money to get good sound anymore.

 

[killdozzer]

My Faith In AH Has Been Restored

We must have done something wrong.

 

[Pogre]

We must have done something wrong.

'Zactly.

 

[AcuDefTechGuy]

I've owned many receivers and expensive audiophile separates. I currently have a 'middle of the price range' name brand AVR and it sounds great. I have no reason to go back to my old audiophile mind set. These days, I'm very happy that I no longer have to worry about spending a large amount of money to get good sound anymore.

Welcome to AH. You have come to the right place.

Join other audiophiles who have spent $100K+ on separates and survived to tell their tales.

These days I'm just looking for more great music and TV shows/movies to enjoy.

 

[ski2xblack]

<eargiant, not to dash your faith in the objectivity of the collective here, but I'm listening to an amp with a distinct sonic signature right now.

But I'm probably more of a hard ass when it comes to the "all amps sound the same" topic. The really do, provided a few basic requirements are met, as has been demonstrated and documented time and again.

Even Gene's article supports this. Take that Panasonic AVR he critiques. That piece has a known wonky output filter and high output impedance, and sure enough, it rolls off the highs and is non-linear into a varying load. This is completely expected, and in no way discredits the well supported claim that amps with low distortion, low output impedance, linear response, and operated within their limits tend to be indistinguishable.

Curiously, Gene resisted our requests to set up an ABX (or even just a crude listening comparison) between a cheap but powerful Crown drive core amp and his blingy Pass Labs monster amps. That would have been more interesting than picking on a poorly designed Panasonic AVR.

 

[equate]

Welcome to AH. You have come to the right place.

Join other audiophiles who have spent $100K+ on separates and survived to tell their tales.

These days I'm just looking for more great music and TV shows/movies to enjoy.

Thank you AcuDefTechGuy. As a former lurker here, I have always enjoyed your posts. I have always learned something.

 

[mtrycrafts]

...

Curiously, Gene resisted our requests to set up an ABX (or even just a crude listening comparison) between a cheap but powerful Crown drive core amp and his blingy Pass Labs monster amps. ...

Interesting you bring this up. Steve Zipser, late of Florida, had a Pass Aleph 1.2. After a long discussion he agreed to do a DBT, in his home, his system, against a Yamaha AX-720 integrated. He, his wife and a friend failed to hear a difference.

https://groups.google.com/forum/?hl=en#!msg/rec.audio.opinion/ZkuGgasUEmM/oCIVassb2T8J

But, that was in the past. Evolution marches on and perhaps it may be different today.

 

[AcuDefTechGuy]

Steve Zipser, late of Florida, had a Pass Aleph 1.2. After a long discussion he agreed to do a DBT, in his home, his system, against a Yamaha AX-720 integrated. He, his wife and a friend failed to hear a difference.

https://groups.google.com/forum/?hl=en#!msg/rec.audio.opinion/ZkuGgasUEmM/oCIVassb2T8J

What are you trying to do? Scare some of these guys away? Make them lose faith again?

They don't want to see any testings or proofs or whatever. Stuff like that has no place in this hobby.

Amps are different. That's it.

 

[mtrycrafts]

What are you trying to do? Scare some of these guys away? Make them lose faith again?

They don't want to see any testings or proofs or whatever. Stuff like that has no place in this hobby.

Amps are different. That's it.

My apologies. I thought I was talking only to ski and no one else will see it. My bad.

Of course I can tell the difference. One only has to read the labels on them; Yam looks different from PASS, et al. I can certainly still read. LOL

 

[Goliath]

Interesting you bring this up. Steve Zipser, late of Florida, had a Pass Aleph 1.2. After a long discussion he agreed to do a DBT, in his home, his system, against a Yamaha AX-720 integrated. He, his wife and a friend failed to hear a difference.

https://groups.google.com/forum/?hl=en#!msg/rec.audio.opinion/ZkuGgasUEmM/oCIVassb2T8J

But, that was in the past. Evolution marches on and perhaps it may be different today.

But didn't you "hear", Steve failed the test due to test pressure? Listening to music on his stereo was just too stressful on his mind that it masked the "night and day" differences between his equipment.

Poor Steve.