the sound of amps

[gene]

I got a question about the sounding of amps.

I'm limiting my question to solid state, not including tubes.

What in the characteristics of an amp makes one sound full and warm in the mid range, or another one hard or lean in the highs, or another one solid in the bass but scratchy in the highs? Where is the reason for all of these different descriptions?

What causes this?

Gene

[gc1]

Design more than anything... I'd wondered this for yrs also, especially after hearing every reason imaginable. Back in the 70's & 80's, several SS amps/preamps sounded as good as tubes, often with better transients. From that time period; Denon, Luxman, McCormack, Belles, Nesterovic, Sony J-FET, Nikko, etc, etc... sounded as musical as any tubes I'd heard, but without the sluggish bass and limited output. And let's not forget marketing... some companies design/ed inferior products hoping you will buy more expensive models in an effort to obtain better "sound".

GC

> I got a question about the sounding of amps.

> I'm limiting my question to solid state, not
> including tubes.

> What in the characteristics of an amp makes
> one sound full and warm in the mid range, or
> another one hard or lean in the highs, or
> another one solid in the bass but scratchy
> in the highs? Where is the reason for all of
> these different descriptions?

> What causes this?

> Gene

[ajinfla]

> I got a question about the sounding of amps.

> I'm limiting my question to solid state, not
> including tubes.

> What in the characteristics of an amp makes
> one sound full and warm in the mid range, or
> another one hard or lean in the highs, or
> another one solid in the bass but scratchy
> in the highs? Where is the reason for all of
> these different descriptions?

> What causes this?

> Gene

The most like culprit is irrational, illogical human behaviour, with vivid imagination.
You will see individuals who fit this mold respond to my post. They are everywhere.

In the unlikely event that there is a real difference, then it would be easily measurable.

If it is not measurable, but somehow the sound is "better", then the designer/builder is improving the product by mystic forces, unknown to science, perhaps with magic or divine intervention. A sprinkle of pixie dust here or a prayer there and out pops a "high-end" product.
Fit for an audio occultist.

If you are hearing any of your above descriptions and can eliminate the imagination of the human mind, the one that can conjure up the image of the Virgin Mary on a grilled cheese sandwich, then you probably have a seriously malfunctioning amplifier that needs to be sent to the nearest service department - or trashed.

cheers,

AJ

[gordoncalder]

> The most like culprit is irrational,
> illogical human behaviour, with vivid
> imagination.
> You will see individuals who fit this mold
> respond to my post. They are everywhere.

> In the unlikely event that there is a real
> difference, then it would be easily
> measurable.

> If it is not measurable, but somehow the
> sound is "better", then the
> designer/builder is improving the product by
> mystic forces, unknown to science, perhaps
> with magic or divine intervention. A
> sprinkle of pixie dust here or a prayer
> there and out pops a "high-end"
> product.
> Fit for an audio occultist.

> If you are hearing any of your above
> descriptions and can eliminate the
> imagination of the human mind, the one that
> can conjure up the image of the Virgin Mary
> on a grilled cheese sandwich, then you
> probably have a seriously malfunctioning
> amplifier that needs to be sent to the
> nearest service department - or trashed.

> cheers,

> AJ

True, there is lots of hocus-pocus out there, but to say that any difference you think you hear is your imagination is a little strong isn't it? Things can be well made or badly made (or just differently made). There are lots of different types of transistors/capacitors/transformers etc. out there
and various configurations for using them, that surely must have an effect on sound.

There's some interesting reading at this site (http://sound.westhost.com/index2.html).

Gordon

[thylantyr]

send me email and we can chat on this topic.

[damkor]

> The most like culprit is irrational,
> illogical human behaviour, with vivid
> imagination.

That's what they say. But interestingly, tell them that you prefer a 2W single ended triode to a receiver, and they say "Well, obviously, a receiver's sound sucks. Try a good stereo amp instead!" And that's funny!

[Paul O]

What affects the sound? Everything. The class of amplification, the type of power supply, the type and number of output devices, the quality of components and construction... Pinning down a particular type of sound to any one of these is a crap shoot at best.
A good quality amplifier should not color the sound when operated within it's designed performamce envelope, and most that I have heard do not, but I can say I have heard subtle differences between amps when compared back to back over the same speakers. I personally discount any opinions that state one amp is superior to another in some form, if the observations were made at different times using different speakers and source material. There are just too many variables, and the human brain and hearing is not capable of making accurate comparisons in this manner.

[Pete Schumacher ®]

> True, there is lots of hocus-pocus out
> there, but to say that any difference you
> think you hear is your imagination is a
> little strong isn't it? Things can be well
> made or badly made (or just differently
> made). There are lots of different types of
> transistors/capacitors/transformers etc. out
> there
> and various configurations for using them,
> that surely must have an effect on sound.

> There's some interesting reading at this
> site
> (http://sound.westhost.com/index2.html).

> Gordon

If you can hear a difference, then you'll likely see a difference in the distortion spectrum or frequency response.

The most rigorous distortion test is T.I.M. or transient intermodulation distortion. Units with low TIM will inevitably have very high slew rates, plenty of loop gain allowing very high feedback levels, and very wide open-loop bandwidth.

[Pete Schumacher ®]

> send me email and we can chat on this topic.

Oh come on Thylantyr!!! Air your thoughts so we can take pot shots at them!!!

;-)

[damkor]

> If you can hear a difference, then you'll
> likely see a difference in the distortion
> spectrum or frequency response.

The difference you are likely to hear when copmparing amps in stereo is in the quality of the 3d image. It is going to be very hard to identify exactly what in the measurements is causing that.

[marlboro]

I agree wholeheartedly with Pete.

Inter modulation distortion and most specifically Transient inter modulation distortion is often the reason why one amp sounds better than others.

And its one of the reasons why you have such an improvement in most systems when you go to bi and tri amping. With a completely separate power amp handling the bass below 200 hz, and another one covering the midranges between 200 and 2500, and another one covering the treble ranges, each can be sized to largely prevent issues rising from TIM. And even if there is an issue with TIM harassing the bass areas, TIm will not impact the sweetness of the treble region.

I've been convinced for some time that the descriptions of amps as sweet in the treble but less bold in the mid etc are related to TIM issues between the different frequency ranges.

You could take an amp that is great in the mid range and treble but less so in the bass range, and have it come out in listening tests as scratchy and harsh in the treble when its really issues orginating in the ability of the amp to handle the mid or more specifically the bass.

Of course, I'm sure there is a difference of opinion about it, but this one is mine.

And once again, I come out agreeing with Pete!!

Marlboro

[edlafontaine]

[wg_ski]

> I agree wholeheartedly with Pete.

> Inter modulation distortion and most
> specifically Transient inter modulation
> distortion is often the reason why one amp
> sounds better than others.

> And its one of the reasons why you have such
> an improvement in most systems when you go
> to bi and tri amping. With a completely
> separate power amp handling the bass below
> 200 hz, and another one covering the
> midranges between 200 and 2500, and another
> one covering the treble ranges, each can be
> sized to largely prevent issues rising from
> TIM. And even if there is an issue with TIM
> harassing the bass areas, TIm will not
> impact the sweetness of the treble region.

> I've been convinced for some time that the
> descriptions of amps as sweet in the treble
> but less bold in the mid etc are related to
> TIM issues between the different frequency
> ranges.

> You could take an amp that is great in the
> mid range and treble but less so in the bass
> range, and have it come out in listening
> tests as scratchy and harsh in the treble
> when its really issues orginating in the
> ability of the amp to handle the mid or more
> specifically the bass.

> Of course, I'm sure there is a difference of
> opinion about it, but this one is mine.

> And once again, I come out agreeing with
> Pete!!

> Marlboro

TIM and basic IM are NOT the same thing. You can't get TIM in a bass amp as the input signal is band limited so the mechanism simply can't happen. You can get IM resulting from clipping, and forcing all that down into the bass region will keep the sound clean in the mid/treble. But that's not transient IM distortion.

Transient IM occurs when there is a loss, or severe reduction in, feedback with fast rise time (transient) signals present. This causes mixing products to be formed much lower in frequency (and thus audible) than the HF signals that originated it. It can be caused by first-stage current starving, a loss of open loop gain due to beta droop, hard slew limit, slow class-G rail switching (like the old Carver cubes - they called it "commutation noise"), or even ultrasonic oscillation.

What does it sound like? It varies from very subtle differences between amps that you can't quite put your finger on, to in severe cases, something that sounds like a stylus mistracking. With most modern amp designs, TIM is not a major issue as the other distortion mechanisms dominate the sound.

[marlboro]

That sounds resonable, and I have no doubt that you are correct. However, most people cannot hear harmonic distortion below 5%, and almost all speakers produce harmonic distortion levels of at least a full 1-5 %.

The fact that you cannot get TIM in a bass amp(I assume that you are speaking of a subwoofer, and its own amp) is not what I'm talking about.

However, if you get into these precise definitions you have departed the realm of my understanding and are approaching intergalactic space for me.

I still agree with Pete, even if I've not properly defined the terms.

Thanks,

Marlboro

> TIM and basic IM are NOT the same thing. You
> can't get TIM in a bass amp as the input
> signal is band limited so the mechanism
> simply can't happen. You can get IM
> resulting from clipping, and forcing all
> that down into the bass region will keep the
> sound clean in the mid/treble. But that's
> not transient IM distortion.

> Transient IM occurs when there is a loss, or
> severe reduction in, feedback with fast rise
> time (transient) signals present. This
> causes mixing products to be formed much
> lower in frequency (and thus audible) than
> the HF signals that originated it. It can be
> caused by first-stage current starving, a
> loss of open loop gain due to beta droop,
> hard slew limit, slow class-G rail switching
> (like the old Carver cubes - they called it
> "commutation noise"), or even
> ultrasonic oscillation.

> What does it sound like? It varies from very
> subtle differences between amps that you
> can't quite put your finger on, to in severe
> cases, something that sounds like a stylus
> mistracking. With most modern amp designs,
> TIM is not a major issue as the other
> distortion mechanisms dominate the sound.

[thylantyr]

> Oh come on Thylantyr!!! Air your thoughts so
> we can take pot shots at them!!!

> ;-)

Three easy payments of $49.95.. Operators
standing buy. If you call within the next hour,
a free sample of SQ rocks in a jar is yours.

[ajinfla]

> That's what they say. But interestingly,
> tell them that you prefer a 2W single ended
> triode to a receiver, and they say
> "Well, obviously, a receiver's sound
> sucks. Try a good stereo amp instead!"
> And that's funny!

I have a 1.5 watt amp in my bedside alarm clock which I can say "I prefer" to any other amplifier. The key words are "I prefer", which is always going to be correct. If I also claim that it is far more musical than any other amp, I would also be correct, since it is whatever sounds best to me that matters to my definition of musicality.
Guess it's all how you choose to look at it.

cheers,

AJ

[ajinfla]

> The difference you are likely to hear when
> copmparing amps in stereo is in the quality
> of the 3d image. It is going to be very hard
> to identify exactly what in the measurements
> is causing that.

So how do suppose the designer of the amp accomplished this feat? Was it magic or divine intervention?
What was the design methodology?

cheers,

AJ

[bangleiii]

The biggest difference is the way the amp handles
the back emf from the speakers, which many if not all tests ignore.
When we hook an amp up to be tested, the first thing that is done is to use a NON INDUCTIVE resistor, well in real life a speaker is any thing but non inductive.
cheaper amps {cheaper in design, not in price}
will "ring" a decaying oscillation, with a speaker, but will not with the resistor.
Try it you will be amazed.

[wg_ski]

> I have a 1.5 watt amp in my bedside alarm
> clock which I can say "I prefer"
> to any other amplifier. The key words are
> "I prefer", which is always going
> to be correct. If I also claim that it is
> far more musical than any other amp, I would
> also be correct, since it is whatever sounds
> best to me that matters to my definition of
> musicality.
> Guess it's all how you choose to look at it.

> cheers,

> AJ

I don't see how you could possibly "prefer" the amp that wakes you up in the morning, no matter how musical it sounds.

[wg_ski]

> The biggest difference is the way the amp
> handles
> the back emf from the speakers, which many
> if not all tests ignore.
> When we hook an amp up to be tested, the
> first thing that is done is to use a NON
> INDUCTIVE resistor, well in real life a
> speaker is any thing but non inductive.
> cheaper amps {cheaper in design, not in
> price}
> will "ring" a decaying
> oscillation, with a speaker, but will not
> with the resistor.
> Try it you will be amazed.

Back EMF produces a *real* component to the speaker impedance, not a reactive one. If anything it makes a speaker easier to drive. Back EMF does not store energy (reactance, oscillation, etc) but has to do with transfer to the surroundings (resistance).

How gracefully an amp handles a reactive load DOES affect how it sounds. Some amps will current limit, some will oscillate, some will distort more, and some don't care. The old Nelson Pass 25W SE solid state class A from years ago is one that just doesn't care. I built one once. Sounds nice.

[bangleiii]

"So how do suppose the designer of the amp accomplished this feat? Was it magic or divine intervention?
What was the design methodology?"

Actually, It can be caused by a feed back of out of phase signals be fed/bled back to the lower stages. It's a defect, but some will find it a quality.
Try taking a speaker and hook it + to + on the amp, you will hear echoes and room ambience sound buried in the recording, it's much more pronounce on live recordings

[marlboro]

I think he was using hyperbole..... or....maybe not!

> I don't see how you could possibly
> "prefer" the amp that wakes you up
> in the morning, no matter how musical it
> sounds.

[marlboro]

[edlafontaine]

[Pete Schumacher ®]

Warren's description of the source of TIM was exactly right. I had described it too, just worded differently.

However, IM distortion can occur in any amp, regardless of it's band limitations. An amp with high slew rate, large loop gain (ratio of open to closed loop gain) and wide open loop bandwidth will not have a problem with TIM, IM, HD or any other distortions other than clipping. The large loop gains, greater than 1000 in most decent amps over the audio band, reduce the open loop distortions by 1000 or more. That's the whole point of negative feedback. And if you have adequate loop gain, you'll reduce distortion to near zero.

[kene]

[skebenin]

> How gracefully an amp handles a reactive
> load DOES affect how it sounds.

I've always believed the way an amp sounds (exluding obvious distortion like clipping) boils down to equilization. Speakers are reactive, and if I'm not mistaken reactivity varies with frequency. Amplifiers are not perfect devices. You can expect that one amp coupled to a pair of speakers will have subtle (or not-so-subtle) differences in frequency response compared to another amp with the same set of speakers.

The most drastic example is a tube amp versus a transistor amp, but even between solid state amps it might explain why one sounds harsh (too much high trebel) while another sounds mellow. It might also explain why one set of speakers sound better with one amp, while another set of speakers sounds better with another.

[AJ]

I do notice a differance between amps. I got a chance to compare a hafler p-125 (dh120 beefed up) against my p-230 (dh220 beefed up) and thier is a pretty big differance.

The 120 has "brighter" highs but a more constricted soundstage. My 230', with a little under double the capacitance in the PS and somewhere around double the power output as the 125' is more laid back, and to me more musical with a more open soundstage and fuller bass.

What makes these amps sound differant? My guess is design mostly. I doubt the designers mean for thier amps to sound a special way. I doubt they all crowd into a room and say the company they work for wants a SS amp that sounds dull through the mids, bright highs and muddy bass. It just happens that way.

This is my opinion.
AJ

[shawn_a]

Doc Olson had his Class A monoblocks/Easy Bake Ovens at Dayton last year and did a little experiment with changing the bias level. The difference was far from subtle. So judging from that it's pretty easy to change the sound of an amp, with a flick of a switch in Matt's instance.

shawn

[bangleiii]

>>I doubt the designers mean for their amps to sound a special way. I doubt they all crowd into a room and say the company they work for wants a SS amp that sounds dull through the mids, bright highs and muddy bass>>

I don't know about this,
I could see this happening at Bose!

[AJ]

Oh yeah. Yep, Bose would be the exception.

[envisionelec]

> Doc Olson had his Class A monoblocks/Easy
> Bake Ovens at Dayton last year and did a
> little experiment with changing the bias
> level. The difference was far from subtle.
> So judging from that it's pretty easy to
> change the sound of an amp, with a flick of
> a switch in Matt's instance.

> shawn

OTOH, I heard no difference at all.

[curt_c]

> The most drastic example is a tube amp
> versus a transistor amp, but even between
> solid state amps it might explain why one
> sounds harsh (too much high trebel) while
> another sounds mellow. It might also explain
> why one set of speakers sound better with
> one amp, while another set of speakers
> sounds better with another.

Now lets throw in speaker cables:

For instance: For a given amplifier, a cable with higher capacitance may sound better with a speaker with too much air, -or with a speaker with that presents a significant inductive load at high frequencies.

C

[Wolf]

> OTOH, I heard no difference at all.

Later,
Wolf

[ajinfla]

[damkor]

No. Any time you preserve the quality of the signal, you are more likely to preserve the details that will let you re-create the ambience that was originally on the recording. It's a matter of good circuitry and good parts. Certainly channel separation is important. So, you don't run left and right circuit board traces close together for one.

[damkor]

Funny. So, can you give me the names of some stereo amps that outperform my 10-year old Onkyo receiver? And tell me the sonic differences I will notice? Because that's always where this goes.

People deny that a certain minimalist tube amp sounds better than anything solid state, and then you tell them you compared it to a budget receiver, and they proclaim the obvious deficienciues of one solid state component against others. You see the irony? All amps sound the same, except the ones in receivers. Is that correct?

[damkor]

I'm trying to get a handle on whether you are being serious or not. You realize that designers make all sorts of decisions that may have a number of effects on the sound, without those effects being their original intention. Most deign considerations have to do with achieving certain measurements parameters, and reducing costs while maintaining performance. Still, they may have an inkling about the effects of those changes.

I like the T-Amp, which is a budget amp with a peculiarly non-flat frequency response. Have you heard it? Does it sound like all the others?

[AJ]

I'm sorry, I mean't between power amps. Yes, i realise that designers must design around cost, and performance. No, i haven't heard the T-amp.

[damkor]

> I'm sorry, I meant between power amps.

No worries. My post was in response to the other guy. But since you bring it up: Is it conventional wisdom that, while all power amps (up to a certian basic quality) sound the same, that there is a wealth of important difference in the driver/line/pre stages and volume controls?

Because I don't buy that. The peculiarities and compromises of the T-Amp, as well as other amps, integrated amp and receivers are not only the result of the volume controls. They are inherent in the power amp section.

[bobleeqsc]

> You can expect that one amp
> coupled to a pair of speakers will have
> subtle (or not-so-subtle) differences in
> frequency response compared to another amp
> with the same set of speakers.

That would be true for amps with unusually high output impedance. Therefore, I think one need not keep that expectation.

-Bob

[bobleeqsc]

A power amp should be a "straight wire with gain"--it should amplify the signal(s) and not add or take away warmth, solidness, soundstage, air, scratchiness, etc. An amp that fails in this regard is altering the signal and therefore just poorly designed or obsolete.

If the amp maintains signal integrity--that is, the output signals are extremely precise duplicates of the input signals--then it will have all the soundstage, air, bloom, etc., that it's supposed to have.

IT'S ALL IN THE SIGNALS!!

-Bob

[AJ]

I completely agree with you. I can hear no differance between my 2$ alps RatShack volume pot and a 30$ Noble that a stupid "audiophile" used in his system down the road from me. You know the "audiophiles" i talk of, the ones that spend upwards of 300$ on rca cables because they have more "air". What a crock.

I can hear minute differances between power amps of a similar quality, but none of them are bad. Like you said, once you hit a certain level of quality it all sounds the same.

[AJ]

What cables would have a higher capacitance? Solid? Large guage or small?

[AJ]

Also, in my case i'd say the amp is a big part of where the "sound" is coming from. All i have in my system is the 2$ alps volume control in a plastic box with some rca connectors for ins and outs. Thats the only thing i have in between my amp and cd player. It will probably stay that way for a while too. I just don't have the money for a good preamp, not that i really need it.

[damkor]

> A power amp should be a "straight wire
> with gain"--

Yes, but none of them are that perfect. That's the point.

[damkor]

> You know the
> "audiophiles" i talk of, the ones
> that spend upwards of 300$ on rca cables
> because they have more "air". What
> a crock.

I am very skeptical of the cables and the Rhodium interconnects. But I am not skeptical that his $35,000 set-up in its entirety, with Avant-garde Duo horns and 2W SET amps sounds somewhat better than mine.

> I can hear minute differances between power
> amps of a similar quality, but none of them
> are bad.

The only interesting difference is when you notice the amp presenting the sound better, in terms of the breadth and depth of the 3D soundstage and the quality and discreteness of the instruments' images. Those factors all contribute to a high sense of realism. That's what I've heard. The differences were subtle but important. And you can see why some people who hear the improvements keep chasing them down to get a better and better sound.

[AJ]

> I am very skeptical of the cables and the
> Rhodium interconnects. But I am not
> skeptical that his $35,000 set-up in its
> entirety, with Avant-garde Duo horns and 2W
> SET amps sounds somewhat better than mine.

Hmmm... I guess i could always take out a loan. Ha.

> The only interesting difference is when you
> notice the amp presenting the sound better,
> in terms of the breadth and depth of the 3D
> soundstage and the quality and discreteness
> of the instruments' images. Those factors
> all contribute to a high sense of realism.
> That's what I've heard. The differences were
> subtle but important. And you can see why
> some people who hear the improvements keep
> chasing them down to get a better and better
> sound.

Couldn't have said it better myself. That was the differance between the hafler p-125 and p-230 when i compared them. Now, these amps are very similar in thier circuitry, but not so alike in sound. The 125 did have a more detailed sound but it wasn't musical to me. Also the soundstage was smaller than my 230, and on some music the vocalist seemed to be in the drummers lap. I just didn't care for it. My 230' on the other hand is much more musical, although less exact, and the soundstage is much wider and more open.

To me, i'd rather give up a little detail for presentation but thats me. And how i like to hear my music.

Also, to the people that hear no differance between amps, what do you use for amplification? And what amps have you listened to?

[curt_c]

> What cables would have a higher capacitance?
> Solid? Large guage or small?

Generally it is how closely the positive and negaitve leads are to each other in the cable.
Typical zip cord, for instance, would have a higher capacitance than if the wires were run individually.

Here's an interesting read that compares 3 cables and to my mind explains why different cables can sound different.

<A HREF="http://sound.westhost.com/cable-z.htm">http://sound.westhost.com/cable-z.htm</A>

C

[AJ]

Hmmm... I suppose if you can hear a .3db differance then yeah, cables can sound differant. Unless i am reading that article wrong. Basically what it comes down to is 12ga zip cord is about as good as speaker cable gets.

[bobleeqsc]

> Yes, but none of them are that perfect.
> That's the point.

They are measurably not perfect. But competently designed and built ones are audibly quite that perfect. That's my point.

-Bob

[bobleeqsc]

> Couldn't have said it better myself. That
> was the differance between the hafler p-125
> and p-230 when i compared them. Now, these
> amps are very similar in thier circuitry,
> but not so alike in sound. The 125 did have
> a more detailed sound but it wasn't musical
> to me. Also the soundstage was smaller than
> my 230, and on some music the vocalist
> seemed to be in the drummers lap. I just
> didn't care for it. My 230' on the other
> hand is much more musical, although less
> exact, and the soundstage is much wider and
> more open.

Did you find what the amp was doing to the signal?

-Bob

[bangleiii]

So, you don't run left and
> right circuit board traces close together
> for one.

The point is, if the stereo is designed well, the
out puts of this type of sound is out of phase
from each channel, thus it is not heard well on a
well designed stereo,,, try it with your best amp,
hook a speaker from L+ to R+ and you will be shocked at what you will hear

[AJ]

What? Was i hearing things?

[bobleeqsc]

> What? Was i hearing things?

???

I asked if you discovered what the one amp did to the signals. If one amp sounds different from another, at least one of them is significantly altering the signals.

-Bob

[AJ]

Sounds like your leading me to something here, but i'm assuming that the amplifiers circuitry has a lot to do with it, and the power differances.

[kene]

[damkor]

if the stereo is designed
> well, the
> out puts of this type of sound is out of
> phase
> from each channel, thus it is not heard well
> on a
> well designed stereo,,

???

, try it with your
> best amp,
> hook a speaker from L+ to R+ and you will be
> shocked at what you will hear

Oh, been there, done that. The cheap surround sound, out of phase gimmick, you mean? I don't know how that relates to good amplifier design resulting in better stereo and better sound.

[damkor]

Do you believe that the Onkyo TX 717Pro is competently designed? It certainly performs perfectly well. And yet, when AB-ed with a Cary 2W amp, the widening of the stereo image was noticeable. The receiver compressed sound images in comparison. The Cary opened them up a bit more.

Is this something I noticed after the more expensive stereo amp was gone? Not really. Sound emory is very short. Was I sure I heard it? Yes. Would most people hear it? Maybe not. The idea that we all hear with the same degree of discrimination is ridiculous.

I can't see how the difference could possibly be the result of added distortion. More distortion leading ot a more realistic musical image? That would be like shuffling the deck a few more times, hoping to pull 4 aces from the top of the pack!

[bobleeqsc]

No, I just asked if you discovered what the amp was doing to alter the signals, not whether you made any assumptions. Thanks.

-Bob

[bobleeqsc]

> Do you believe that the Onkyo TX 717Pro is
> competently designed? It certainly performs
> perfectly well. And yet, when AB-ed with a
> Cary 2W amp, the widening of the stereo
> image was noticeable. The receiver
> compressed sound images in comparison. The
> Cary opened them up a bit more.

I don't know if the Onkyo is competently designed. It would be interesting to compare them in an ABX test, though.

> The idea that we all hear with
> the same degree of discrimination is
> ridiculous.

True. Did someone offer that idea?

> I can't see how the difference could
> possibly be the result of added distortion.
> More distortion leading ot a more realistic
> musical image? That would be like shuffling
> the deck a few more times, hoping to pull 4
> aces from the top of the pack!

I'm sorry, what added distortion are you talking about?

-Bob

[damkor]

<A HREF="http://www.michael.mardis.com/sonic/measure/5066-freq.html">http://www.michael.mardis.com/sonic/measure/5066-freq.html</A>

[damkor]

> I don't know if the Onkyo is competently
> designed. It would be interesting to compare
> them in an ABX test, though.

OK. Onkyo is normally thought of as just the sort of budget/quality product that puts boutique audio products to shame.

> True. Did someone offer that idea? [that everyone hears the same.]

Well, the usual reply to person A, who hears something that person B does not is that A is a "golden ear", which is a euphemism for someone who pretends to hear a difference when they don't or can't.

> I'm sorry, what added distortion are you
> talking about?

Well, when you say you prefer an amp whose measurements are inferior (THD, whatever), it is said that you are preferring the extra distortion, its effect on the frequency response. The idea that you are hearing a quality that is not in the measurements is not given much validity.

You SHOULD do an ABX test. Include any number of AV receivers, and try out some QSCs and some 2W SET integrateds.

[bobleeqsc]

> Well, the usual reply to person A, who hears
> something that person B does not is that A
> is a "golden ear", which is a
> euphemism for someone who pretends to hear a
> difference when they don't or can't.

That's possible. The problem is that the vast majority of "I heard …" claims are highly unreliable.

> Well, when you say you prefer an amp whose
> measurements are inferior (THD, whatever),
> it is said that you are preferring the extra
> distortion, its effect on the frequency
> response.

Sometimes added THD, or other effects or processing, is euphonic. Accuracy and preference are not always the same.

> The idea that you are hearing a
> quality that is not in the measurements is
> not given much validity.

Which measurements? A small set of measurements isn't likely to tell much. Any characteristic alteration of a signal that is great enough to be heard, though, can be identified and measured, one way or another.

> You SHOULD do an ABX test. Include any
> number of AV receivers, and try out some
> QSCs and some 2W SET integrateds.

Yup.

-Bob