GRollins, post #269.
Sorry to go back so many posts, but I think you completely missed the point.
The one camp claims distortion is unimportant but at the same time cannot, or will not, tell the rest of us what it is that makes a great sounding amp. The other camp simply says that one of the factors that is important is to have low distortion, and the techniques for attaining this are fairly straight forward - which the former camp vehemently disagrees with but cannot tell us why. Around the circle we go again, catch 22 etc etc. Oh, of course, there is the discrete vs IC dimension to this discussion as well . . . .
Sorry to go back so many posts, but I think you completely missed the point.
The one camp claims distortion is unimportant but at the same time cannot, or will not, tell the rest of us what it is that makes a great sounding amp. The other camp simply says that one of the factors that is important is to have low distortion, and the techniques for attaining this are fairly straight forward - which the former camp vehemently disagrees with but cannot tell us why. Around the circle we go again, catch 22 etc etc. Oh, of course, there is the discrete vs IC dimension to this discussion as well . . . .
IMO, the reason we buy stuff and the engineering behind it, are two entirely separate things. IMO, it's also getting worse. Years ago, cars were sold at least somewhat on the design of the engine, how the suspension was set up, etc. You could special order various aspects of the construction when it was built- rear end ratio, trim details, wheels, even some engine options. Today, I have little idea what's under my hood at all. I have the "sport" option. No idea what that means. The detailed information isn't considered important by the manufacturers, nor, as far as I can tell, by customers. What is important is appearance and a bunch of intangibles concerning the vehicle and the company that made it. Sell the sizzle, not the steak, unless you want to go bankrupt.
In audio, you better have a good story. Mystique is essential. Numbers are out of style. Heck, facts are out of style.
Re distortion. IMO, low distortion numbers guarantee nothing. An amp can have low THD and be unsatisfying. That number covers only part of what an amp has to do. But... I have no interest in amps with high distortion. The purpose of an amp is to reproduce the signal, and efforts to do that as well as possible will tend to yield low distortion numbers.
People seem to want a set of measurements that will tell them how an amp sounds. I still waffle on whether decently designed amps even have a sound. Every time I try to investigate things like conductor materials and cap construction, the differences become elusive and typically evaporate, or they resolve into well understood phenomenon. Other things, like the idea that different brands of metal resistors, or solder, sound different, are incredibly far-fetched from any scientific standpoint. I try to keep an open mind on this stuff, but eventually have to fall back on what's scientifically known, and what I can or can't hear. The fact is, I only hear most of it when I'm fooling myself. Dig deeper and the effects go away.
Everybody has an agenda, myself included. Manufacturers need the mystique. If we discovered some previously unknown "x-factor" that completely controlled amp performance, no one would have any market advantage. Sales would go to the cheapest vendor, and all the high end people would go out of business. It's not in their best interest to have all the answers known. Buyers and constructors also have a need to believe certain things, to validate their purchases or design decisions. Everybody also has some overall understanding of how the world works, that can't be violated or escaped from.
My working theory- Some time in the distant past, there was a genetic fork in the road. Some people were cursed with the ability to hear subtle differences in sound, sometimes real but often imagined. This ability remains extremely important to them. Another group is identical to the first, except that they can't hear the subtle differences. This ability remains extremely important to them. Others became tin ears, completely unconcerned about obvious flaws that would drive the first two groups nuts. We call them "teenagers", with MP3 players and thumping bass in their cars. What this group thinks is unclear, as communication is nearly impossible. A fourth group got nothing. Background music is fine, as long is it isn't too loud, too bright, or too thumpy. You can pick on them all you want, because none will be part of this forum. Some of the four groups have foolishly intermarried, resulting in many impossible-to-classify sub-groups. The main feature of all these groups is that none were given the ability to find common ground with the others.
In audio, you better have a good story. Mystique is essential. Numbers are out of style. Heck, facts are out of style.
Re distortion. IMO, low distortion numbers guarantee nothing. An amp can have low THD and be unsatisfying. That number covers only part of what an amp has to do. But... I have no interest in amps with high distortion. The purpose of an amp is to reproduce the signal, and efforts to do that as well as possible will tend to yield low distortion numbers.
People seem to want a set of measurements that will tell them how an amp sounds. I still waffle on whether decently designed amps even have a sound. Every time I try to investigate things like conductor materials and cap construction, the differences become elusive and typically evaporate, or they resolve into well understood phenomenon. Other things, like the idea that different brands of metal resistors, or solder, sound different, are incredibly far-fetched from any scientific standpoint. I try to keep an open mind on this stuff, but eventually have to fall back on what's scientifically known, and what I can or can't hear. The fact is, I only hear most of it when I'm fooling myself. Dig deeper and the effects go away.
Everybody has an agenda, myself included. Manufacturers need the mystique. If we discovered some previously unknown "x-factor" that completely controlled amp performance, no one would have any market advantage. Sales would go to the cheapest vendor, and all the high end people would go out of business. It's not in their best interest to have all the answers known. Buyers and constructors also have a need to believe certain things, to validate their purchases or design decisions. Everybody also has some overall understanding of how the world works, that can't be violated or escaped from.
My working theory- Some time in the distant past, there was a genetic fork in the road. Some people were cursed with the ability to hear subtle differences in sound, sometimes real but often imagined. This ability remains extremely important to them. Another group is identical to the first, except that they can't hear the subtle differences. This ability remains extremely important to them. Others became tin ears, completely unconcerned about obvious flaws that would drive the first two groups nuts. We call them "teenagers", with MP3 players and thumping bass in their cars. What this group thinks is unclear, as communication is nearly impossible. A fourth group got nothing. Background music is fine, as long is it isn't too loud, too bright, or too thumpy. You can pick on them all you want, because none will be part of this forum. Some of the four groups have foolishly intermarried, resulting in many impossible-to-classify sub-groups. The main feature of all these groups is that none were given the ability to find common ground with the others.
Conrad Hoffman said:
Hi Conrad,
Main problem here (IMHO) that the end result for a music reproduction is not what we hear (or think that we hear) but the emotional effect of the music on us. And that effect in NOT the result of only our conscious perception - our subconscious plays greater role in it. Moreover, that presents a trap in a way - more we trying to make sense out of what we hear further we go from this main purpose of the music, as we can not control our emotions - as soon as we are trying to analyze them we break them and only can pick up the pieces.
Different people get their pleasure out of music in different ways and their perception could be affected by different imperfections in reproduction. There is no simple single answer as there is no single model of a human to fit all of us
. Somebody is happy with $20 MP3 player, somebody is happy only with a live performance of a good orchestra.What I am trying to say is that we don't know enough about our subconscious perception of sound. To research even conscious part of it is difficult enough, but our emotions from music only partially result from our conscious hearing.
Somebody's buying a hi-fi system usually does it to get some pleasure from music. To that end measurements are not really applicable
. The task of a hi-fi designer is to walk a narrow path between the engineering side of the design and the end purpose of the equipment - playing the music for pleasure of a human, not to satisfy a THD analyzer.Cheers
Alex
Listening tests - what is the source material?
Lots of comments about listening tests here but little comment about the source material that is listened to. Classical music? Popular music? Spoken word? SACD/DVD-A, redbook CD, lossy compressed digital, vinyl, tape, shellac, optical film? Vintage or modern? Does the source material itself affect the listener and her/his experience and therefore influence subjective evaluation as suggested by the previous post?
Lots of comments about listening tests here but little comment about the source material that is listened to. Classical music? Popular music? Spoken word? SACD/DVD-A, redbook CD, lossy compressed digital, vinyl, tape, shellac, optical film? Vintage or modern? Does the source material itself affect the listener and her/his experience and therefore influence subjective evaluation as suggested by the previous post?
Conrad Hoffman said:
<OT>
IMHO, not a very good example, and not a very good take on the art/engineering of automobiles (let's ignore the North American penchant for big trucks when they really aren't necessary -- the old male "mine is bigger than yours syndrome").
1st off, your typical car today is way better than one 20 years ago. Faster, better handling, much safer, more fuel efficient, and longer lived.
And those last 2 have a very profound effect on the vehicle you can buy today... both from government regulation and the US tendency towards silly lawsuits.
Think of what you get when you buy a $25k car vrs a $25k amplifier (yes there are huge differences in econopmy of scale).
dave
Scott Wurcer, I want to use the AD797. Would it help to use a constant current diode to the (-) supply from the output to make it class A? How much current would be optimum? PS, I have some residual 7th harmonic in my measurement system. I am using both the 744 and the 797 in the system. Would strapping these components with a constant current source get rid of it? A measurement wonk needs to know! 
Planet10, I never said modern cars aren't far superior to those of yesteryear. Goodness knows my inexpensive Mazda beats my old Triumph on every single thing you could possibly judge a car on. My point is how the makers go about selling them. Detailed knowledge about anything technical seems to be at an all time low, so delving into the details of why a car, or an amp, is better, won't get you very far in the marketplace. As for $25K amplifiers, on the one hand, I can't imagine any justification for that price, other than "what the market will bear". Whatever it has in it, a good DIYer could do it far cheaper. On the other hand, I look at all the nice test equipment one can buy, the top end Tek digital scopes, Agilent's nice LCR meter, or anything at all to do with calibration, and they all cost near $20K or much more. The production volumes are probably similar or greater than the $25K amp. So I dunno. Why do I think one is overpriced, and the others fair? None of those items will be coming to my basement lair any time soon.
Nuvistor- I mostly listen to ordinary CDs of rock, folk, and classical. Lately I've been buying used LPs and transferring them to CD for home and car. Just picked up a mess of old Ventures. That means 99% of my listening is digital, and most of it is through halfway decent headphones. The rest is in the car. Only rarely do I put an LP through the full analog chain. For that reason, I'm thinking about building a serious class A headphone amp, because there are certainly shortcomings in the digital chain. I noticed that when recording an old Command Enoch Light album. Very clean with a lot of sharp transient stuff. There was a definite difference between what I could achieve at 44.1 and 96kHz and playing with the number of bits. Fortunately, most material isn't that tough to deal with, and is much more musically satisfying than old Command albums.
Nuvistor- I mostly listen to ordinary CDs of rock, folk, and classical. Lately I've been buying used LPs and transferring them to CD for home and car. Just picked up a mess of old Ventures. That means 99% of my listening is digital, and most of it is through halfway decent headphones. The rest is in the car. Only rarely do I put an LP through the full analog chain. For that reason, I'm thinking about building a serious class A headphone amp, because there are certainly shortcomings in the digital chain. I noticed that when recording an old Command Enoch Light album. Very clean with a lot of sharp transient stuff. There was a definite difference between what I could achieve at 44.1 and 96kHz and playing with the number of bits. Fortunately, most material isn't that tough to deal with, and is much more musically satisfying than old Command albums.
Conrad Hoffman said:
I don't think car sales men are any different now than ever... an afficiando has always had to either do research himself or find a like minded (but rare) salesman.
Cars today are much much more complex, and the background knowledge needed to even think about understanding the stuff in cars really raises the bar.
But the internet also means you have more ready access to those that have that knowledge... i wouldn't be surprised if in some cases you can actually get an email conversion going with one of the design engineers.
dave
Conrad Hoffman said:Nuvistor- I mostly listen to ordinary CDs of rock, folk, and classical. <snip> Fortunately, most material isn't that tough to deal with, and is much more musically satisfying than old Command albums.
I guess you use the Command albums for listening tests and ordinary CDs for most pleasure listening?
For my electronics listening tests, mostly preamps and headphone amps, I use vinyl more than digital, classical or jazz with minimal dynamic range compression if possible, signal chain differences at low levels seem more apparent with vinyl. I don't have any hi-rez digital, perhaps that would tilt the balance.
Unfortunately the artistic range of good source material in redbook CD is narrower with the increased use of dynamic range compression, I don't expect the likes of late 70's Steely Dan productions anymore.
I'm not sure what the real value of exquisitely optimized audiophile signal chains is with most modern uncompressed digital source material, and at the rate the music business is changing, I expect this to deteroriate further as distribution moves to downloads of lossy compressed material.
Conrad Hoffman said:
Of course, Tek and HP have been optimizing production efficiencies for decades. Small audio developers don't have the benefit of such experience.
Interesting contrast to autos. My bottom-to-midline first system - Concord CR-250 receiver, Dynaco A35s and an AR-XA w/ Shure M91ED - would be roughly $3200 in equivalent 2007 dollars. That buys an infinitely better vinyl-based system today and many would still complain about price madness!
inuendo
Ya know...there's a subtle inuendo often present in some of the "expert" postings and musings on forums that may very well be the cause of skeptiscism from many of the "less informed" participants in the relevant fields of discussion, to wit:
Said expertise is often wielded as a large bat to somehow prove that product A is sonically superior to product B; when pressed for details, one is then admonished to accept the mantra espoused in the thread as gospel. Take "sound" of amplifiers, for example. Over ten years ago a Krell advocate on the infamous RAHE maintained that "amps is amps", yet professed to prefer said Krells over most anything else. When a subjectivist would question this seeming illogic, the answer would be "personal preference". If personal preference is the reason for selecting one overbuilt tank over another, why not just say so, rather than all the mud slinging and discord about cause and effect. No hidden agenda hear (sic)
I for one can hear differences in amps, I've listened to hundreds through all sorts of systems. Anyone who doesn't hear differences in amps under normally ill defined conditions isn't listening. Question is, does it matter?
That said, the differences I hear are often many many orders of magnitude below differences I hear by adjusting, say, the toe-in on a set of speakers, or changing my seating position, or cleaning the ear wax out of my ears, etc.
So I'll continue improving the speaker-ear interface and source selection as best I can, having "expertise" in other fields (materials science, chemistry, mineralogy, etc.) and, as AJ says... just listen...and leave the musings about minutiae to the unending ramblings of the relevant "experts" here...
It is entertaining reading, though.... ergo ego
Ya know...there's a subtle inuendo often present in some of the "expert" postings and musings on forums that may very well be the cause of skeptiscism from many of the "less informed" participants in the relevant fields of discussion, to wit:
Said expertise is often wielded as a large bat to somehow prove that product A is sonically superior to product B; when pressed for details, one is then admonished to accept the mantra espoused in the thread as gospel. Take "sound" of amplifiers, for example. Over ten years ago a Krell advocate on the infamous RAHE maintained that "amps is amps", yet professed to prefer said Krells over most anything else. When a subjectivist would question this seeming illogic, the answer would be "personal preference". If personal preference is the reason for selecting one overbuilt tank over another, why not just say so, rather than all the mud slinging and discord about cause and effect. No hidden agenda hear (sic)
I for one can hear differences in amps, I've listened to hundreds through all sorts of systems. Anyone who doesn't hear differences in amps under normally ill defined conditions isn't listening. Question is, does it matter?
That said, the differences I hear are often many many orders of magnitude below differences I hear by adjusting, say, the toe-in on a set of speakers, or changing my seating position, or cleaning the ear wax out of my ears, etc.
So I'll continue improving the speaker-ear interface and source selection as best I can, having "expertise" in other fields (materials science, chemistry, mineralogy, etc.) and, as AJ says... just listen...and leave the musings about minutiae to the unending ramblings of the relevant "experts" here...
It is entertaining reading, though.... ergo ego
Auplater- I fool with this stuff and post here because I can't stop myself from asking "why?". Why do I hear what I hear. Why don't I hear what you hear? Why can't you hear what I hear? How can I make the whole thing sound more pleasing? Thank goodness there are commercial manufacturers here, as the place would be far poorer without them. Don't you have any intellectual curiosity about the low level nuts and bolts causes of the effects?
What I hear
yeah, Conrad, I wonder about them too. I wonder about quantum entanglement as well. I wonder about lots of things. I wouldn't have patents if I didn't do alot of wondering.
Trouble is, the presentation by the commercial mfgs. seems, at times, to be clouded with agenda. That's my real difficulty... my 5 decades+ of experience has taught me a healthy dose of skeptiscism re: telling me what I can and cannot hear.
Low level 'nuts & bolts' are great, if someone would be kind enough to share their repeatable methodology of determining their relevance, rather than grandstanding with statements like "dirty sand" etc. total nonsense.
Conrad Hoffman said:
yeah, Conrad, I wonder about them too. I wonder about quantum entanglement as well. I wonder about lots of things. I wouldn't have patents if I didn't do alot of wondering.
Trouble is, the presentation by the commercial mfgs. seems, at times, to be clouded with agenda. That's my real difficulty... my 5 decades+ of experience has taught me a healthy dose of skeptiscism re: telling me what I can and cannot hear.
Low level 'nuts & bolts' are great, if someone would be kind enough to share their repeatable methodology of determining their relevance, rather than grandstanding with statements like "dirty sand" etc. total nonsense.
Re: What I hear
Actually that's what's missing from this site. No one is talking about anything that can't be substantiated by someone else. And there is no interest in striking out discussing what might be done.
I was excited to find this site and have learned a lot, but as you say "wondering about things" and hoping to bounce ideas off others is met by the equivelent of an air horn competing with the conversation.
Sometimes I don't care that the theory says something else, I just want to think it through with intelligent input.
I find it easy to say I'm wrong after discussion. I don't when someone tells me so by quoting the bible.
I actually borrowed this concept from a book a friend lent me, but I can't remember the name. This discourse has been enlightening, I'm bored now and want to go home.
By the way I have 20 -25 patents to my name depending on how you search. I'm an EE no physics.
Regards, Mike
Conrad Hoffman said:
auplater said:
Actually that's what's missing from this site. No one is talking about anything that can't be substantiated by someone else. And there is no interest in striking out discussing what might be done.
I was excited to find this site and have learned a lot, but as you say "wondering about things" and hoping to bounce ideas off others is met by the equivelent of an air horn competing with the conversation.
Sometimes I don't care that the theory says something else, I just want to think it through with intelligent input.
I find it easy to say I'm wrong after discussion. I don't when someone tells me so by quoting the bible.
I actually borrowed this concept from a book a friend lent me, but I can't remember the name. This discourse has been enlightening, I'm bored now and want to go home.
By the way I have 20 -25 patents to my name depending on how you search. I'm an EE no physics.
Regards, Mike
Eventually I'll burn out and switch hobbies. I have a lot of 'em and tend to rotate on a rather long time scale. It's been about ten years since I was last serious about audio. Meanwhile, I've tried to be very honest about what I can hear and can measure. IMO, it falls way short of what others claim to be able to hear and lots of people have gone way beyond what I have in terms of SA. Still, I believe audio quality can be very well quantified on the test bench, though the results can't be summarized in a couple of numbers that non-electronic people can understand. IMO, I'm in a minority in that belief here. The problem is finding others who like to do the same sort of tests, and compare results. I'd love to get some kind of consensus on what parameters are important, and start a list of what you have to address in a design, and what you have to check on the bench, but too few people even think it's a valid approach. For now, that won't stop me from trying to walk a gentle line between viewpoints, learn what I can, and offer what I've seen.
- Status
- Not open for further replies.