Which Amp

[DMK]

I just want to say that I do not find a lot to disagree with in DMKs comments in this area. I disagree with his notion that there are "subtle" differences in amps, but what I really object to is his standards of proof and evidence. We have been over this a lot, but the scientifically correct view is that it is up to those making an assertion to prove it. Scientific investigation never tries to find all instances of a phenomina (e.g., all listeners). The philosophical postion that "not everyone has been tested" is merely a dodge to get the onus of proof off of those making a claim. This could be said about any scientific law or principle (e.g., not all matter has been check to see if gravity is the same for it as other matter).

The other thing that bugs me is this notion that we should all be "fair" and "accept" the views of others as they have a right to their beliefs and opinions. That is all well add good, but there is such a thing as evidences and that evidence is being ignored by a large number of "audiophiles", so much so that the extreme subjectivist magazines are now the mainstream in audio publications. Many ridiculous and unsupported concepts are taken as fact in the audio world and I find that detrimental to the hobby (or whatever you want to call it).

Perhaps the worst notion in home audio is that idea that you can simply listen and compare components. The number of variables affecting what you here is very large and a listener cannot control them all. Perhaps the most ignored variable is the listener's own expectations--one's expectations are PROVEN to effect ones perceptions therefore you can never get control of that variable unless you blind yourself. The second variable most ignored is level, but there are many, many other factors that make it impossible to get a comparison that, for example, removes all audible variables except the current from the amp. Audiophiles' "own perceptions" ARE powerful, they just happen to be very unreliable. (This unreliabity has been established in several listening tests that I AM aware of.)

I'd really like to talk about skeptic's idea that our standard measurements are lacking. There are two problems with his position at this point:

1) he merely criticizes by saying that frequency response measurements into 8 ohms of resistive impedance is inadequre, instead of giving some evidence that frequecy response changes into 4 ohms (or non-resistive loads) with typical amps. In other words, he needs some evidence other than his opinions.

2) he keeps saying he hears difference in amps, but there is no credible evidence (I am aware of) that anyone has demonstated this. If he can he should share the details with us (and not use old amps that may not be performing up to spec).

I did not say that there are subtle differences in power amps, at least not one SS to another. I said it's possible. You are not even allowing for the possibility that you could be wrong. I'm certainly no scientist but that doesn't sound very scientific to me.

I wasn't aware that I had standards of proof and evidence! I guess if I do, they are pretty simple. I don't require proof of any kind when it comes to someone's perceptions. If they say they heard it, that's fine with me. I may believe that they merely perceived something and it had nothing to do with the different amp or whatever and that is my right. In most cases, all these people are stating is an opinion of what their perception lead them to believe. You are free to discount it. If you do (and you obviously do in each and every case), why not just leave it at that? The bigger question is, what makes you think that anyone on this board or in any remote corner of the globe owes you any proof of what they perceive???? Put another way, who cares if you want proof? And how is the fact that some people ignore evidence detrimental to the hobby, particularly if their experiences fly in the face of that evidence?

I agree with rb's assessment of your paragraph regarding simple listening and comparing. I subscribe to it myself and it was very well written. I'm not trying to piss you off; I'm just asking how you can be so positive that there are no sonic diffs in amps simply because you've seen no evidence to support the contrary view. It helps your case but it doesn't prove it. For all you know, some guy who doesn't give a rat's behind what the scientific world thinks has performed successful DBT's with SS power amps with identical specs and he just hasn't bothered or cared to come forward.

[mtrycraft]

[QUOTE=RobotCzar] Have I ever asked you about your views on direct-to-disc LPs?

QUOTE]

I had some before the CD was affordable. They sounded nice. Those vinyls have long been sold

[DMK]

[QUOTE=mtrycraft]

Have I ever asked you about your views on direct-to-disc LPs?

QUOTE]

I had some before the CD was affordable. They sounded nice. Those vinyls have long been sold

When did the CD become affordable? I missed that! I was buying new vinyl in 1989 for about $8 just before I bought my first CD player and gasped at the $14 price tag for CD's. By the time I realized that the CD was a sonic step backward, new vinyl had all but disappeared. But maybe some of your LP's are now in my collection!

I never heard a CD (to my knowledge) until 1989. Did you adopt the format pretty early? I've heard the very early players were pretty awful. They've seemed to stabilize these days and my current experiences are much better than those I had in my early digital days.

[rb122]

Hey rb, how are you doing? I have taken a part time job at an instructor and my class uses a computer-lab with fast Internet access, so I have some time to read and respond in AR (while they are working on projects). Find any good LPs lately? Have I ever asked you about your views on direct-to-disc LPs?

Thanks for your kind comment. As you know, I think there are many factors that are important in getting a good (i.e., realistic) result in home audio. Too bad so many people are attending to the wrong ones (in my opinion). Pehaps it is simply easier for some people to spend a lot of money on snobby equipment rather than to learn what really matters.

I am well, sir! It's good to see you back on the forum, albeit somewhat sporadically. I trust things are going well for you.

Have I found any good LP's lately? Yes, indeed! I had to pass over a fairly large cache of 1950's and 1960's jazz because the price was prohibitive but I've found a number of Concord Jazz discs from the '70's and quite a fair amount of classical. I've purchased only a very few CD's this year. I'll have to check and see if I own any direct-to-disc LP's. I'm really a poor excuse for an audiophile! As you know, I take a purely personal stance on audio i.e what sounds proper to me is proper. I'm not too concerned about accuracy as it is measured. My system is modest by audiophile standards and it was all purchased on the used market. I have a day job to help support my family and my "play" money comes from my gigs which are few and far between these days! My point is that I purchased my system almost at once and I have no desire and no means to go through the arduous upgrade process that consumes my audiophile brethren

I believe most audiophiles don't really want to know how the equipment does what it does, assuming it does anything different. If the mystique goes, the interest might wane.

As always, it's a pleasure chatting with you. Best wishes!

Rob

[DMK]

I am well, sir! It's good to see you back on the forum, albeit somewhat sporadically. I trust things are going well for you.

Have I found any good LP's lately? Yes, indeed! I had to pass over a fairly large cache of 1950's and 1960's jazz because the price was prohibitive but I've found a number of Concord Jazz discs from the '70's and quite a fair amount of classical. I've purchased only a very few CD's this year. I'll have to check and see if I own any direct-to-disc LP's. I'm really a poor excuse for an audiophile! As you know, I take a purely personal stance on audio i.e what sounds proper to me is proper. I'm not too concerned about accuracy as it is measured. My system is modest by audiophile standards and it was all purchased on the used market. I have a day job to help support my family and my "play" money comes from my gigs which are few and far between these days! My point is that I purchased my system almost at once and I have no desire and no means to go through the arduous upgrade process that consumes my audiophile brethren

I believe most audiophiles don't really want to know how the equipment does what it does, assuming it does anything different. If the mystique goes, the interest might wane.

As always, it's a pleasure chatting with you. Best wishes!

Rob

...let me see if I have the facts straight and then I'll add one or two of my own:

1) You found a bunch of '50's and '60's used jazz LP's for sale somewhere.
2) You did not purchase same, meaning they were, at least for a short time after you found them, still available.
3) You dishonored your A/R brothers by not telling us where they were.
4) I'm going to have to hurt you! I'm sorry, but you deserve nothing less!

I just found a bunch of the same era jazz LP's about two months ago. The price was high and it cost me the Sota Cosmos turntable I was saving up for but they were worth it! That Roy DuNann at Contemporary Records in particular could sure record! Absolutely stunning sound.

[mtrycraft]

When did the CD become affordable? I missed that! I was buying new vinyl in 1989 for about $8 just before I bought my first CD player and gasped at the $14 price tag for CD's. By the time I realized that the CD was a sonic step backward, new vinyl had all but disappeared. But maybe some of your LP's are now in my collection!

I never heard a CD (to my knowledge) until 1989. Did you adopt the format pretty early? I've heard the very early players were pretty awful. They've seemed to stabilize these days and my current experiences are much better than those I had in my early digital days.

I meant the CD palyer was affordable to switch. CD was about what the direct to disc were. I never saw then at $8 but closer to $15 so I had a few to try.
Now that you ask, I don't remember when I changed but I heard it by 1985 or so. I doubt I paid $1k for the new stuff so the price had to have come down a lot.
I had no problems with the early players what I heard. Sounded great, better than vinyl, so I started to save for the day of the coming

[hertz]

All amps sound the same in ideal conditions. Ideal world and conditions exist only in Utopia. In this real world, we are dealing with mass market amp makers who are cutting corners everywhere.So most of the amps end up sounding different.

Yesterday I had been to this friend's house. He has klipsch reference series speakers as fronts. He has an onkyo reciever for movies and a Rotel RB1070 power-pre combo for stereo. When I reached his house, he was watching a movie. I suggested he play one of my fave soungs (stimela from the burmester test cd 3) using the reciever. Well it sounded okay but not at all natural.The reciever was set to direct mode. Then we switched to the rotel. Man what a difference ! Natural and involving with hardly a hint of digital glare. The control on the woofer was awesome. What sounded like a wooly thump on the reciever sounded like a real thwack on the bass drum with the rotel.Well..I can go on.....

[Geoffcin]

All amps sound the same in ideal conditions. Ideal world and conditions exist only in Utopia. In this real world, we are dealing with mass market amp makers who are cutting corners everywhere.So most of the amps end up sounding different.

Yesterday I had been to this friend's house. He has klipsch reference series speakers as fronts. He has an onkyo reciever for movies and a Rotel RB1070 power-pre combo for stereo. When I reached his house, he was watching a movie. I suggested he play one of my fave soungs (stimela from the burmester test cd 3) using the reciever. Well it sounded okay but not at all natural.The reciever was set to direct mode. Then we switched to the rotel. Man what a difference ! Natural and involving with hardly a hint of digital glare. The control on the woofer was awesome. What sounded like a wooly thump on the reciever sounded like a real thwack on the bass drum with the rotel.Well..I can go on.....

If you have the time please read my review of the Cambridge Soundworks T500 speakers on Audioreview.com. After purchasing them I got them home and DIDN'T like them all that much. I was ready to return them when a though crossed my mind, and said; "perhaps they are just showing you the receivers faults". Sure enough, after hooking them up to my PS Audio amp the difference was startling. Anyone who says that amps don't make a difference has never listed to different amps. With some speakers it makes all the difference in the world.

[CannondaleSuperVee]

"Anyone who says that amps don't make a difference has never listed to different amps."

Geoffcin and hertz, once again I will restate that if you are sure you can tell the diffrence between two amps go take the challange, if you are so sure you can tell the diffrence its an easy $10000.00 in your pocket. You can pick the amps, speakers and music. Later

[DMK]

I meant the CD palyer was affordable to switch. CD was about what the direct to disc were. I never saw then at $8 but closer to $15 so I had a few to try.
Now that you ask, I don't remember when I changed but I heard it by 1985 or so. I doubt I paid $1k for the new stuff so the price had to have come down a lot.
I had no problems with the early players what I heard. Sounded great, better than vinyl, so I started to save for the day of the coming

In 1989, I paid about $200 for a player that I could now buy for about $80, feature-wise. Not too bad. Actually, the advent of the CD started me on the upgrade path to audiophiledom. I thought my system all of a sudden sounded bad but turns out it was those horrid CD's. 15 years later, they're better but those in the first several batches are still bad. Better than vinyl? Still waiting....

What's this got to do with amps?

[mtrycraft]

All amps sound the same

Did I really say this? Or, that is the unreliable perception that people are jumping on?


In this real world, we are dealing with mass market amp makers who are cutting corners everywhere.So most of the amps end up sounding different.

Then those differences would show up under DBT listeing conditions. Only the ones that are broken, poorly designed do.

Yesterday I had been to this friend's house. He has klipsch reference series speakers as fronts. He has an onkyo reciever for movies and a Rotel RB1070 power-pre combo for stereo. When I reached his house, he was watching a movie. I suggested he play one of my fave soungs (stimela from the burmester test cd 3) using the reciever. Well it sounded okay but not at all natural.The reciever was set to direct mode. Then we switched to the rotel. Man what a difference ! Natural and involving with hardly a hint of digital glare. The control on the woofer was awesome. What sounded like a wooly thump on the reciever sounded like a real thwack on the bass drum with the rotel.Well..I can go on.....


And you arrived at this amazing differences under bias controlled conditions? Or, just another unreliable perception, poor setup?

[mtrycraft]

Anyone who says that amps don't make a difference has never listed to different amps. With some speakers it makes all the difference in the world.

Yep, that is why the books are full of null results of amp DBT comparisons. But then who ever said you had to listen only with your ears. After all, your eyes are very important to tell components apart, right?

I wonder why people claim to hear differences between the same amp presented twice, under bias controlled conditions? It should be a slam dunk, right?

[Sealed]

The *PRIMARY* problem with amp perception (other than loudness) is hearing a difference when an amp cannot handle the speaker it is connected to.

A 50 wpc reciever will *NOT* be able to adequately drive speakers lie B&W N802's or ATC SCM-35's , so naturally a stout 200 wpc separate will sound different because it can properly drive them. The best the 50wpc reciever could achieve before running out of steam would be a moderate ly low volume. Any dealer or home demo can prove this in minutes.


Tube amps have this problem, because if they struggle with a load, they will sound slow and bloated. It doesn't need to be hyper scrutinized to hear that a 9wpc set amp sounds flabby when attempting to drive a difficult load it wasn't designed for.

On a benign load, like Paradigm Titans or axiom m22's for example, it would be almost impossible to tell audible differences beyond the minute.

[RobotCzar]

The *PRIMARY* problem with amp perception (other than loudness) is hearing a difference when an amp cannot handle the speaker it is connected to.

A 50 wpc reciever will *NOT* be able to adequately drive speakers lie B&W N802's or ATC SCM-35's , so naturally a stout 200 wpc separate will sound different because it can properly drive them. The best the 50wpc reciever could achieve before running out of steam would be a moderate ly low volume. Any dealer or home demo can prove this in minutes.


Tube amps have this problem, because if they struggle with a load, they will sound slow and bloated. It doesn't need to be hyper scrutinized to hear that a 9wpc set amp sounds flabby when attempting to drive a difficult load it wasn't designed for.

On a benign load, like Paradigm Titans or axiom m22's for example, it would be almost impossible to tell audible differences beyond the minute.

This writer is making a point that is often overlooked: The factor that is most audible of power amps is power output. You will hear a difference in a 200 wpc and 50 wpc amp if you play inefficient speakers (which is not a bad quality) very loudly. The distortion goes up with output and the 50 watt amp may even be clipping. In my experience, power output matters in terms of an audible difference. I like to have all the power I can get (i.e., afford).

"Driving a difficult load" is another story that is the basis of skeptic's claim he can hear differences. Just what a "difficult load" is, is not clear. Surely speakers with a nominal imediance of 4 ohms and above is not "difficult", but if your speakers sometimes get down to 3 ohms (like my AR98s) then you might have some problems with less well-designed amps (note that I did not say cheap ones). You will need a special amp if your speakers present 2 ohms or less a significant at significant frequency ranges.

"Adequately drive" should mean, "not cause your amp to clip or to output significant (i.e., audible) distortion". Those who think that many amps cannot adequately drive many speakers are on to hook to provide some evidence beyond uncontrolled, subjective listening opinions (i.e., distortion measurements and frequency response plots).

Now, will you be able to tell your amp is having some problems is casual listening to music? Highly unlikely.

[skeptic]

"This writer is making a point that is often overlooked: The factor that is most audible of power amps is power output. You will hear a difference in a 200 wpc and 50 wpc amp if you play inefficient speakers (which is not a bad quality) very loudly. The distortion goes up with output and the 50 watt amp may even be clipping. In my experience, power output matters in terms of an audible difference. I like to have all the power I can get (i.e., afford)."

This is quite true as soon as you begin to challenge the limits of available amplifier power. The sound of an amplifier clipping can be wretched. How the amplifier recovers from clipping is also important. The notion that vacuum tube amplifiers are somehow superior to solid state amplifiers because they clip with predominantly even harmonics while the other clips with predominantly odd harmonics or visa versa is absurd. ALL clipping can be awful. It is important to select an amplifier which will produce sufficient power to play the loudest levels required without any clipping regardless of the type.

""Driving a difficult load" is another story that is the basis of skeptic's claim he can hear differences. Just what a "difficult load" is, is not clear. Surely speakers with a nominal imediance of 4 ohms and above is not "difficult", but if your speakers sometimes get down to 3 ohms (like my AR98s) then you might have some problems with less well-designed amps (note that I did not say cheap ones). You will need a special amp if your speakers present 2 ohms or less a significant at significant frequency ranges."

This was the explanation HH Scott gave us for the failure of their high power Mosfet receiver in the late 1960s driving AR3s. They claimed the impedence of the nominally 4 ohm speaker was below one ohm at some frequencies. AR of course denied it. My Dynaco Stereo 120 didn't much care for my 4 ohm nominal Teledyne AR9s either. After 23 years of reliable service, it was taken out when driven hard into those speakers. There are other factors however which can affect the perceived sound of a speaker when connected to different amplifiers. Frequency response is one of them. Too bad the only specifications you're likely to see is the response at 1 watt into an 8 ohm resistive load. Who knows what happens at other impedences and power levels. Who knows what limitations the eddy current and hysterisis losses in output transformers do. Furthermore, loudspeakers are not even passive loads but generate a back emf which brings us to the issue of damping factor. Another shortcoming of vacuum tube amplifiers is their high output impedence which gives the amplifier comparitively less control of heavy woofer cones resulting in muddier, boomier bass than with a high quality solid state amplifier. Furthermore, tube amplifiers have uneven frequency responses even at one watt and harmonic distortion and intermodulation distortion orders of magnitude higher than the best solid state amplifers. Can these limitations be overcome? To a degree. But solid state amplifiers are not without their own shortcomings and many early ones suffered from crossover notch distortion in their output stages making them sound bright and harsh. This was later substantially reduced in better biasing of bipolar designs and in Mosfet designs.

""Adequately drive" should mean, "not cause your amp to clip or to output significant (i.e., audible) distortion". Those who think that many amps cannot adequately drive many speakers are on to hook to provide some evidence beyond uncontrolled, subjective listening opinions (i.e., distortion measurements and frequency response plots)"

This is where amplifier design engineers have really fallen down on the job. They haven't bothered to delve into the relationships between amplifiers and loudspeakers beyond what they were handed down by their instructors from generations past. Therefore, on paper many of them look identical when they are anything but.

Of all amplifier designs, the 8 watt per channel SET costing many hundreds or thousands of dollars would appear to be the absolute worst value on the market. If anyone has the onus of proving that these amplifiers outperform far cheaper and more powerful designs in ways which mitigate their inability to adequately drive any but a tiny fraction of the loudspeakers available on the market, it seems to me that it is these people who have the burden of proof. So far all we have is testimonial evidence from individuals with no scientific studies to even back up their listening claims. Just like the claims for after market cables, moving coil phonograph cartridges, and a slew of other audiophile mantras.

[mtrycraft]

[QUOTE=skeptic

Of all amplifier designs, the 8 watt per channel SET costing many hundreds or thousands of dollars would appear to be the absolute worst value on the market. .[/QUOTE]


How about those costing into the 5 or even 6 figures

[mtrycraft]

When amps are compared under DBT conditions, one of the condition is not driving it beyond its design limits. Of course it will sound different outside that envelope

So, if a speaker needs 100watts of power, how would a 50 watt amp deliver unless the signal is of a dynamic nature and the amp has 3dB headroom.

[skeptic]

Here's a trick I've mentioned here before that an old electrical engineer friend of mine told me from back in the vacuum tube days (actually he was a professor of electrical engineering); play music at a very soft level with very efficient loudspeakers. Put your ear right up to the speakers. This will reveal crossover notch distortion (yes you can get it in tube amplifiers too) because the region around the cutover from positive to negative going and visa versa where crossover notch distortion occurs will be a relatively large proportion of the total sound wave. This kind of distortion contributed to the harsh brittleness of many solid state amplifiers in the early 1960s. The notion that all amplifiers could conceivably sound the same is easily dispelled by anyone who has an amplifier test report from high fidelity magazine or audio magazine from the early to mid fifties. Just look at those awful frequency response curves. Those old tube amplifiers often just don't have the clarity or bass impact of more modern solid state amplifiers. Their harmonic distortion could get pretty high too with ratings of 1% or higher not uncommon. The switch from vacuum tube to solid state amplifiers was driven as much by market demand as by the desire to advertise the newest technology. When the top echelon of the day, Marantz and McIntosh went solid state, and even Dynaco, the handwriting was on the wall for vacuum tubes. There seems to be a nostalgia for these old sets. They have a charm which transcends their usually inferior sounding performance. They have individuality, each with its own distinctive personality. They have that warm glow at night that can be comforting, a kind of electronic hearth. They were far more artistically designed and some of them had excellent human engineering compared to today's sterile looking black boxes with remote controls and blue fluorescent digital displays. But they just don't sound as good to me.

[mtrycraft]

Here's a trick I've mentioned here before that an old electrical engineer friend of mine told me from back in the vacuum tube days (actually he was a professor of electrical engineering); play music at a very soft level with very efficient loudspeakers. Put your ear right up to the speakers. This will reveal crossover notch distortion (yes you can get it in tube amplifiers too) because the region around the cutover from positive to negative going and visa versa where crossover notch distortion occurs will be a relatively large proportion of the total sound wave.

Will it be audible at the normal listeing seat? I don't listen up so close

This kind of distortion contributed to the harsh brittleness of many solid state amplifiers in the early 1960s.

Oh, ok. How about much later, into the 70s and beyond to today?

The notion that all amplifiers could conceivably sound the same is easily dispelled by anyone who has an amplifier test report from high fidelity magazine or audio magazine from the early to mid fifties. Just look at those awful frequency response curves.

OK, so those were poorly designed or par for the time period. The other aspect of DBT liseti8ng of amps is level matching to .1dB spl. So, obviously it would not be possible with that FR spec.

Those old tube amplifiers often just don't have the clarity or bass impact of more modern solid state amplifiers. Their harmonic distortion could get pretty high too with ratings of 1% or higher not uncommon.

Again, they are broken by later specs

[hertz]

All amps sound the same

Did I really say this? Or, that is the unreliable perception that people are jumping on?


In this real world, we are dealing with mass market amp makers who are cutting corners everywhere.So most of the amps end up sounding different.

Then those differences would show up under DBT listeing conditions. Only the ones that are broken, poorly designed do.

Yesterday I had been to this friend's house. He has klipsch reference series speakers as fronts. He has an onkyo reciever for movies and a Rotel RB1070 power-pre combo for stereo. When I reached his house, he was watching a movie. I suggested he play one of my fave soungs (stimela from the burmester test cd 3) using the reciever. Well it sounded okay but not at all natural.The reciever was set to direct mode. Then we switched to the rotel. Man what a difference ! Natural and involving with hardly a hint of digital glare. The control on the woofer was awesome. What sounded like a wooly thump on the reciever sounded like a real thwack on the bass drum with the rotel.Well..I can go on.....


And you arrived at this amazing differences under bias controlled conditions? Or, just another unreliable perception, poor setup?

That's exactly what I am talking about.If you randomly pick and compare amps with the same specs from some 10 manufacturers, you will find that most of them are designed poorly. This results in diffrences in sound with revealing speakers.I tried out
some five amps at home before deciding on my NAD C350.So the consumer has to be careful. When I did my checks I had a pair of 96 db wharfedales.I checked out a higher power spec Yamaha and nakamichi including some others. Both the yamaha and nakamichi had a tough time driving the wharfedales especially at high volumes. They lost control and sounded "shouty" wheras the NAD sounded controled and musical. I checked out the lesser powered 320 bee also. Even that sounded fine. I learned that day that
spec sheet is as good as TOILET PAPER when it comes to mass market manufacturers.

I know it is very much different because the frown that I had on my face when I listened to the reciever was replaced with a
smile which extended from ear to ear with Rotel. This smile came on automatically so it is a function of my Brain which reacted positively to the music reproduced by the rotel.Remember that this is a song I listen to atleast twice a week on my my NAD/B&W setup for the last year.

[rb122]

...let me see if I have the facts straight and then I'll add one or two of my own:

1) You found a bunch of '50's and '60's used jazz LP's for sale somewhere.
2) You did not purchase same, meaning they were, at least for a short time after you found them, still available.
3) You dishonored your A/R brothers by not telling us where they were.
4) I'm going to have to hurt you! I'm sorry, but you deserve nothing less!

I just found a bunch of the same era jazz LP's about two months ago. The price was high and it cost me the Sota Cosmos turntable I was saving up for but they were worth it! That Roy DuNann at Contemporary Records in particular could sure record! Absolutely stunning sound.

As much as I enjoy my "A/R brothers", I would be silly to even breathe a hint of where this vinyl be reside if I ever wanted another chance at it. I believe I've mentioned before that you, in particular, are gluttonous when it comes to LP's. I would not want to add to that. It is, after all, a sin!

Roy is still around! I don't think he's recording much anymore, though. Have you heard "Way Out West" by Sonny Rollins or any of the old Hampton Hawes LP's? THAT, my friend, is what small band jazz sounds like in a club. Good luck finding that quality on CD.

[RobotCzar]

That's exactly what I am talking about.If you randomly pick and compare amps with the same specs from some 10 manufacturers, you will find that most of them are designed poorly. This results in diffrences in sound with revealing speakers.I tried out
some five amps at home before deciding on my NAD C350.So the consumer has to be careful. When I did my checks I had a pair of 96 db wharfedales.I checked out a higher power spec Yamaha and nakamichi including some others. Both the yamaha and nakamichi had a tough time driving the wharfedales especially at high volumes. They lost control and sounded "shouty" wheras the NAD sounded controled and musical. I checked out the lesser powered 320 bee also. Even that sounded fine. I learned that day that
spec sheet is as good as TOILET PAPER when it comes to mass market manufacturers.

This is exactly the kind of response that is unhelpful to the discussion and to those new to home audio. You say the the amps are "designed poorly" but you give no explanation of what you mean by that. Did you study the schematics or measure their performance?

The implication is that you heard a difference. But, you did not control for the many variables that could have caused an audible difference that are unrelated to amplifier design. Therefore your report is worthless. Also, because nobody (I know of, or have heard of in 30 years of home audio) has been able to distinguish properly performing amps (not most tube amps) we have a very good reason to doubt that you can. (Let me also say that many of those tested claimed they could easily hear differences, but failed to do so when tested--so reports from audiophiles are extremely unreliable.)

[skeptic]

"Therefore your report is worthless. Also, because nobody (I know of, or have heard of in 30 years of home audio) has been able to distinguish properly performing amps (not most tube amps) we have a very good reason to doubt that you can. "

One amplifier I can report sounded harsh and bright was an early model made by a company called Acoustech which was later bought out by Koss. It had surprisingly high harmonic distortion for a solid state amplifier running about 1%.

Among vacuum tube amplifiers, even Marantz must have felt that there was a difference in sound because they provided a switch on the Model 8 power amp which allowed the user to switch from pentode to triode operation but with less maximum power (I think the reduction was from 60 watts for the pentode to 40 watts for the triode.

The heart and soul of any audio power amplifer regardless of its type is its power supply. You can often tell a lot about the quality of an amplifier just by how heavy and large it is. A huge power transformer and filter capacitors suggests plenty of available power and conservative design. These are the heaviest and most expensive electronic components in the amplifier (except of course in the case of vacuum tube amplifiers where the output transformers and tubes themeselves can cost a bundle.) Does circuit topology or circuit element selection matter? Can you really hear the difference between old wax paper capacitors and polypropylene capacitors? Can you hear a difference in the poor selection Amber made using Sylvania switching transistors in output stages of their units? Will two separate power supplies and careful layout prevent crosstalk between channels to an audible degree? What about poor use of feedback? Is there such a thing as "transient intermodulation distortion" or is that just a myth? BTW, the Crown DC 300 which is so maligned by audiophiles had a very fast slewing rate and should have had very low TIM. And what about the IC 150 preamplifier. If they sound as good as anything out there, they are the steal of the century putting out enormous power, offering tremendous control flexibility, being practically bulletproof even after 35 years of use, and available for far less than most new equipment. And I would have hunted a pair down except that today, Crown makes brand new units which sell at very reasonable prices. The even more powerful CE-1000 only costs $450 including shipping. Crown claims even better audible performance for their Studio Reference series which for comparably powered units is about three times higher but still far below Bryston, Krell, and Mark Levinson. While still maligned by audiophiles, these ultra reliable, ultra powerful units would also seem a great bargain. On paper at least, these are among the best value in audio amplifiers on the market. Anybody got one to report about it?

[RGA]

Hi Fi choice level matched to .1db - blind panels(all componants in this manner including amplifiers, receivers and speakers) They have a sound quality componant to their sessions - the manufacturers themselves sit in on the tests as part of the panels much of the time - and they don't even choose their own equipment as being best all of the time. I would love to get some back issues but shipping from the UK I have a feeling will set me back heavy on the Duty. Their method defeats some of the psychological concerns of test stress which is more valuable to the consumer.
http://hifichoice.co.uk/reviews.asp

[mtrycraft]

Hi Fi choice level matched to .1db - blind panels(all componants in this manner including amplifiers, receivers and speakers) They have a sound quality componant to their sessions - the manufacturers themselves sit in on the tests as part of the panels much of the time - and they don't even choose their own equipment as being best all of the time. I would love to get some back issues but shipping from the UK I have a feeling will set me back heavy on the Duty. Their method defeats some of the psychological concerns of test stress which is more valuable to the consumer.
http://hifichoice.co.uk/reviews.asp

Unfortunately their protocol is not statistically validated or published.
They also have other porblems, panel discussions, etc. Flawed.