two different amps sound the same?

[izeek]

You're definitely in the wrong place to be talking about sound difference between amps, i.e. similarly specified amplifiers matched for volume of output. In particular, it's the wrong place to talk about subjective differences since there is a crew here who distain and ridicule those who express subjective impressions.

But then one must grant that the rigorous testing, e.g. "blind" ABX comparisons, proven time & again that statistically people cannot identify which amp is which.

As for price differences, different power and other objective capacities and one thing; others are quality of construction. cosmetics, and the reputation of the maker.

my bad.

 

[ta240]

Which wouldn't be audible at all unless there were some pretty shoddy manufacturing tolerances in place...

Keeping in mind this amp is about 25 years old and aside from aging components, has been through who knows what sort of abuse or even modifications in that time.

 

[escksu]

Market segmentation.
Different people can afford to spend different amounts. If someone can afford to spend $5k buying an amp from you, you don’t want them to buy the $500 model that you’re aiming at people with less money. So you put it in a fancier case with a silky-smooth volume knob and ‘upgrade’ a couple of things inside so you can claim it sounds better.


Not all components are the same though. They differ in terms of tolerances and, perhaps more importantly, stability. Shaving a few pennies from the BOM by using 85C capacitors instead of 105C ones is not really a good idea though.

Tell you something about electrolytic caps. Temperature rating isnt everything. There are other factors esp. Lifespan. There are 105c for just 1000hrs, there are 85c and 5000hrs, even 15000hrs. Ripple current is another, ESR also. So, unless your amp has extremely high internal temp, 85C but 5000hrs is actually more desirable than 105c but just 1000hrs.

Also, if your amp internal temp is 100c, capacitor lifespan isnt the only thing you will worry about.

 

[escksu]

Yes. But the reverse, that measurable is audible, isn't necessarily true.

No doubt i do agree with you on this. But one issue, whose ears and there is also no way to determine if its placebo or not. If 2 out of 10 can but remaining 8 cannot, is that considered audible or not?

 

[Sgt. Ear Ache]

No doubt i do agree with you on this. But one issue, whose ears and there is also no way to determine if its placebo or not. If 2 out of 10 can but remaining 8 cannot, is that considered audible or not?

Well, on an individual basis there is a way to determine if it's placebo or not.

But it's difficult to really say without knowing exactly what measurements we are talking about here. If we're saying that different examples of the same amp will vary based on the performance tolerances of their internal components, what are the measurements of that variance that relate to audible differences?

 

[ta240]

Output impedance changes frequency response. Below an extreme example.

SUMMER MUSINGS: No... Not all amplifiers sound the same (but many do! ;-).

A blog for audiophiles about more objective topics. Measurements of audio gear. Reasonable, realistic, no snakeoil assessment of sound, and equipment.

archimago.blogspot.com

A fantastic reminder that speakers are not resistive loads and amplifiers will behave differently with reactive loads connected to them.

It is amazing that a site so enamored with 'science' continues to ignore the resistive vs reactive load debate. And hasn't ever done any matched level in-room response measurements like this. Science is great but if you only look for the data you want, you are much more likely to get the results that you want rather than the truth.

But then again we still get Amir's subjective impression of the speakers without any double blind comparison after he has tested them to know what to listen for. Which is exactly the same as a salesman telling someone what speakers will sound like before doing a demonstration and the person hearing what they were told they would hear.

 

[izeek]

Ask you a question, if a $500 device performs as good as a $5000 one, why should the company sell for $500? If all performs the same, why would any company even bother to make equipment of different series, range, prices? Why not just make 1 and be done with it?

When you open up an equipment, you can commonly find different components (esp. brand) between their low cost and high end models. If all components are the same, why not just use the cheapest and maximise your margins?

Now, if you are the buyer, why would you want to spend more if all are the same?

Ask you a question, if a $500 device performs as good as a $5000 one, why should the company sell for $500? If all performs the same, why would any company even bother to make equipment of different series, range, prices? Why not just make 1 and be done with it?

When you open up an equipment, you can commonly find different components (esp. brand) between their low cost and high end models. If all components are the same, why not just use the cheapest and maximise your margins?

Now, if you are the buyer, why would you want to spend more if all are the same?

but did it make it better in performance or just better because of higher quality components?

 

[ta240]

yes, but I would define an amp that had a 5db divergence from neutral response as anything but good.

but wait...that measurement is in room response. Why would we use that for an amp? Oh, comparing the in room response between the two amps. OK...so again, one of those amps is not neutral. By definition it's doing what an amp ain't ought to do.
....

I guess if you are just hooking your amp up to resistors or maybe test equipment then there would be no need to see how it responds to a reactive load.

Why not measure them in room with speakers? That is how they will be used.

The room will affect both amps exactly the same so the in room response should be identical between the two amps, correct?

Otherwise, as is clearly shown, two amps can produce noticeable differences in sound in the real world.

Yes, which only highlights the lunacy of the traditional subjective audition.

So, measure the in room response.

Yes. But the reverse, that measurable is audible, isn't necessarily true.

The in-room comparison shows a difference at some frequencies of as much as 5 db. Wouldn't that be audible?

I'm not sure they could remember what each system sounded like even during the ABX switchover. My auditory memory, as well as everyone else's, is extremely short. I can focus on one aspect, high frequency for example, between two sources, but never the whole spectrum difference.

Just like when watching a music video and the camera pans to the drummer, all of a sudden the drum sound become focused.

Which is why I'm not a fan of the quick switch comparison. I have found with different changes to my setup I often won't notice any difference other than that I will stop listening to music or I will listen a lot more over a long period of time. I will realize that since the last change I haven't had the setup on for more than a couple of hours in the last month. And another change and I'll have it on for 8+ hours a day every day for weeks at a time. I can't do the audio reviewer thing of "I heard this" or didn't hear that but I will listen a lot more or a lot less and it is over a long enough time period that it isn't just mood or other factors.
For example, prior to switching to an external DAC on my Squeezebox touch I had completely stopped playing music. I'd say in a year the music was on for not more than a few hours. Even though in the car I really enjoyed listening.

 

[charleski]

There are other factors esp. Lifespan. There are 105c for just 1000hrs, there are 85c and 5000hrs, even 15000hrs

Lifespan ratings are generally a function of the case size, which itself is determined by the capacitance and voltage rating.

I’m not quite sure what point you’re trying to make here.

 

[Sgt. Ear Ache]

I guess if you are just hooking your amp up to resistors or maybe test equipment then there would be no need to see how it responds to a reactive load.

Why not measure them in room with speakers? That is how they will be used.

The room will affect both amps exactly the same so the in room response should be identical between the two amps, correct?

Otherwise, as is clearly shown, two amps can produce noticeable differences in sound in the real world.




So, measure the in room response.

"
5. While I can show and hear a difference between the Pass SIT-2 and my Hypex nCore quite easily, realize that within reasonable objective operating parameters, amps will sound alike! Suppose you put two very disparate (say an amp costing $10,000 and another at $500 of various dimensions, power, features) but "clean" amplifiers side by side with the following characteristics:

- Flat frequency response 20Hz to 20kHz measured with a typical resistive load (like 4Ω).
- Low distortion <1% THD for whatever maximum watts you need (100W into 8Ω likely adequate for most of us).
- Adequately high damping factor say 20x across the frequency spectrum for your speaker's nominal load assuming there are no prolonged portions of the electrical impedance curve dipping far below that.
- Low amplifier noise floor devoid of hum, hiss, noise spurs above your listening room's ambient noise level when the amp volume control is set to desired listening amount.

Likely, you'll find such "clean" amps will be indistinguishable in a volume-controlled blind test with actual music regardless of whether they're Class A or AB or D. Tube or solid-state. Lower or higher feedback.

Manufacturers love to differentiate and imply sonic differences using technical descriptions (eg. Class A, low feedback) and some audiophiles likewise might swear by them without evidence that such claims are true - or take the time to listen in a controlled environment, much less blinded!

As usual, some folks will also gravitate towards luxury products and the pride of ownership that can come with that. Yeah, tube amps can glow nicely and their physical "warmth" might accentuate the perception of sonic warmth. Likewise, big price tags and seeing an imposing 100lb behemoth amplifier in a fancy showroom may have strong psychological effects. When it comes to sound quality, let's try not to conflate "high fidelity" sound with the "non-utilitarian benefits" of luxury products."

 

[Matias]

The article pretty much ends this discussion. Yes: amplifiers can sound different, the difference is measurable in room and it can be audible.
The end.

 

[Sgt. Ear Ache]

The article pretty much ends this discussion. Yes: amplifiers can sound different, the difference is measurable in room and it can be audible.
The end.

Yeah, but nobody has claimed amps "can't" sound different.

 

[Mart68]

A fantastic reminder that speakers are not resistive loads and amplifiers will behave differently with reactive loads connected to them.

It is amazing that a site so enamored with 'science' continues to ignore the resistive vs reactive load debate. And hasn't ever done any matched level in-room response measurements like this. Science is great but if you only look for the data you want, you are much more likely to get the results that you want rather than the truth.

But then again we still get Amir's subjective impression of the speakers without any double blind comparison after he has tested them to know what to listen for. Which is exactly the same as a salesman telling someone what speakers will sound like before doing a demonstration and the person hearing what they were told they would hear.

you are right that this does sometimes account for perceived amplifier differences. This was discussed a while back and IIRC no-one disagreed. The difficulties inherent in testing with 'real world' speaker loads were also discussed.

 

[ta240]

you are right that this does sometimes account for perceived amplifier differences. This was discussed a while back and IIRC no-one disagreed. The difficulties inherent in testing with 'real world' speaker loads were also discussed.

Discussed, but never really addressed. My guess is because the current methods give the results they want from the tests, so why change. Showing that the real world performance of amps might actually differ is not desired.

Saying it is difficult to measure correctly and moving on is really just accepting faulty data. And not making any disclaimer about it on all the tests, seems like bad science. How hard is it to do a level matched in-room comparison like in the chart above?

We demand proper methods for subjective testing but accept faulty methods for objective testing.

 

[iMickey503]

Exactly. It's the nature of the beast. Once a technology is solved, it just gets less and less expensive. DVD players that used to cost thousands now cost $89 at Walmart. Amps aren't complicated things.

I can fix just about ANY engine.
Amplifier? Nope. Simple? Not for me.
It still amazes me that people can just look at a schematic and tell how the amplifier will behave or sound.

I think from layman's point of view, there's a big difference between a person who can understand the principal and actually do it in practice. As doing the later is much more difficult with the situations of real-world use that amplifiers face on a daily basis.

I always like to bring up the Class A Amplifier kits sold on Ebay. I think John Audio Tech did a build on one.
The fact that he also had no problem fixing and diagnosing the problems of an amplifier it's quite honestly impressive to me.

for some of you I bet it's just a typical Monday morning at work. still impressive nonetheless.

 

[Mart68]

Discussed, but never really addressed. My guess is because the current methods give the results they want from the tests, so why change. Showing that the real world performance of amps might actually differ is not desired.

Saying it is difficult to measure correctly and moving on is really just accepting faulty data. And not making any disclaimer about it on all the tests, seems like bad science. How hard is it to do a level matched in-room comparison like in the chart above?

We demand proper methods for subjective testing but accept faulty methods for objective testing.

You can see from both the amplifier and speaker measurements provided whether the amp will be immune to difficult loads and whether or not a speaker is a difficult load. What more is required?

 

[JayGilb]

A fantastic reminder that speakers are not resistive loads and amplifiers will behave differently with reactive loads connected to them.

It is amazing that a site so enamored with 'science' continues to ignore the resistive vs reactive load debate. And hasn't ever done any matched level in-room response measurements like this. Science is great but if you only look for the data you want, you are much more likely to get the results that you want rather than the truth.

But then again we still get Amir's subjective impression of the speakers without any double blind comparison after he has tested them to know what to listen for. Which is exactly the same as a salesman telling someone what speakers will sound like before doing a demonstration and the person hearing what they were told they would hear.

Why is it amazing ? He's making standard, repeatable measurements and a non-inductive resistive load not impacted by frequency will better represent measurements across different topologies.

The difference is that we get both standardized measurements and Amir's personal impression and we can ignore both or neither.
Go into any audio showroom and you're not going to be handed measurement data, just their opinion based on what merchandise their boss is asking them to push that month.

 

[Doodski]

I can fix just about ANY engine.
Amplifier? Nope. Simple? Not for me.
It still amazes me that people can just look at a schematic and tell how the amplifier will behave or sound.

I think from layman's point of view, there's a big difference between a person who can understand the principal and actually do it in practice. As doing the later is much more difficult with the situations of real-world use that amplifiers face on a daily basis.

I always like to bring up the Class A Amplifier kits sold on Ebay. I think John Audio Tech did a build on one.
The fact that he also had no problem fixing and diagnosing the problems of an amplifier it's quite honestly impressive to me.

for some of you I bet it's just a typical Monday morning at work. still impressive nonetheless.

After ~8 months of full time electronics class and study you could follow most schematics too. You'll still need years of real world experience to iron out the details. This is the kind of class where they move very fast and expect the student to have read the literature the night before. Expect pure theory, a ~1300-1600 page textbook and the associated lab book at least every 2 months. The perpetual math can be a bit daunting at first when combined with the theory and new buzzwords but it all comes together in time. I stayed awake till 12-1am every week night studying, back in class at 8:00 am and on Sundays we had a ~2 hour study meeting and collaborated. The study meeting I guess got me maybe 5%+ better marks because it gives one the opportunity for the students to teach each other whenever a student has trouble with something. The engineers receive more comprehensive training for ~4 years.

 

[Doodski]

Go into any audio showroom and you're not going to be handed measurement data, just their opinion based on what merchandise their boss is asking them to push that month.

Nail'd it!

 

[Sgt. Ear Ache]

I can fix just about ANY engine.
Amplifier? Nope. Simple? Not for me.
It still amazes me that people can just look at a schematic and tell how the amplifier will behave or sound.

I think from layman's point of view, there's a big difference between a person who can understand the principal and actually do it in practice. As doing the later is much more difficult with the situations of real-world use that amplifiers face on a daily basis.

I always like to bring up the Class A Amplifier kits sold on Ebay. I think John Audio Tech did a build on one.
The fact that he also had no problem fixing and diagnosing the problems of an amplifier it's quite honestly impressive to me.

for some of you I bet it's just a typical Monday morning at work. still impressive nonetheless.

I never said they were simple to me lol.