Maybe easier to just purchase some good amplifiers, listen, critique and report back to John, this way you can spend your spare time fixing the TVR and playing with the Kids...
Just saying .........
http://www.hafler.com/techsupport/pdf/DH-120_amp_man.pdf
I have a cleaned up version I will try and post when I remember where that picture posting thing is.
There is a lot in this amp not discussed in either text. Back to reading.
I have a cleaned up version I will try and post when I remember where that picture posting thing is.
There is a lot in this amp not discussed in either text. Back to reading.
A.Wayne, Well I did just buy an HCA 1200.... When I am allowed, I want to get get my wife's super critical hearing to compare it with her favorite Rotel and the Creek I picked up. Buying good amps is both easier and cheaper, but what fun is that? I have found this subject fascinating.
I sold my cars as my knees could not handle the clutches any more and it was getting too hard to get in and out of them. They were a nice diversion for about 20 years. Now back to audio.
I sold my cars as my knees could not handle the clutches any more and it was getting too hard to get in and out of them. They were a nice diversion for about 20 years. Now back to audio.
Are u kidding this is audio we are talking about, even if u only purchased and modified ur units , u could spend the rest of ur life trying to get it right.
The fun is listening to the music after modding, as to the tvr, they have hydraulic clutches now.....
Hi a.wayne,
Another thing you might consider about working with older equipment. Depending on the age of the thing, it may very well be in need of attention. So if someone dives in and performs a "mod" (net based instructions), you will never know if the improvement is real (probably is), nor will you know whether you fixed a problem by replacing a defective component or not. Very often, there are parts that do not fail completely. It's more of a reduction of performance over time. Listening to an amplifier that needs service to try and gauge it's performance is a total waste of time to begin with.
Now, trying to design by ear is typically not going to lead you to a successful design. Therefore, it is very probable that a person could spend their entire life trying to get it right and never succeeding. Let's just say that you pretty much need some testing and measurements to keep you on track.
Yes, it is audio we are talking about. All the more reason to make sure equipment you are trying to listen to is operating properly. Otherwise you have just wasted your time. What is the point of that?
Hi John,
-Chris
Well, that is only if you actually know what you are doing and have the skills to do the work. Otherwise you may destroy a perfectly good amplifier.
For starters, proper words might help. "Text speak" should be reserved for the tiny screen world. Remember that punctuation placement can affect the meaning.
Another thing you might consider about working with older equipment. Depending on the age of the thing, it may very well be in need of attention. So if someone dives in and performs a "mod" (net based instructions), you will never know if the improvement is real (probably is), nor will you know whether you fixed a problem by replacing a defective component or not. Very often, there are parts that do not fail completely. It's more of a reduction of performance over time. Listening to an amplifier that needs service to try and gauge it's performance is a total waste of time to begin with.
Now, trying to design by ear is typically not going to lead you to a successful design. Therefore, it is very probable that a person could spend their entire life trying to get it right and never succeeding. Let's just say that you pretty much need some testing and measurements to keep you on track.
Yes, it is audio we are talking about. All the more reason to make sure equipment you are trying to listen to is operating properly. Otherwise you have just wasted your time. What is the point of that?
Hi John,
Since we have the schematic posted for all to refer to, would you please let people know what you don't like about the design of this amplifier? It is better than many, but not as good as some others out there for sure. A good opportunity for you to teach. Might be fun for you.
-Chris
Hi,
The fault lies squarely with certain academics and researchers, who not have an unhealthily large influence in certain professional organisation and academic circles but are part of a bunch of debunkers that have been telling everyone since the 1970's that once certain minimal standards are met all electronics sound indistinguishable and hence there is no need for further research.
The degree to which this group has impeded the possibility of any real progress becomes more obvious if it is noted that they control the access to publication in the major recognised professional/academic journal regarding sound reproduction.
Of course, the situation is not helped by the fact that the more reasonable researchers, antagonised by being denied access to publication and by being ridiculed have either abandoned the field of sound reproduction (Matti Ottalla is an example - he moved into control systems and telecom's) or simply elect not to share what they may have learned.
Ciao T
The fault lies squarely with certain academics and researchers, who not have an unhealthily large influence in certain professional organisation and academic circles but are part of a bunch of debunkers that have been telling everyone since the 1970's that once certain minimal standards are met all electronics sound indistinguishable and hence there is no need for further research.
The degree to which this group has impeded the possibility of any real progress becomes more obvious if it is noted that they control the access to publication in the major recognised professional/academic journal regarding sound reproduction.
Of course, the situation is not helped by the fact that the more reasonable researchers, antagonised by being denied access to publication and by being ridiculed have either abandoned the field of sound reproduction (Matti Ottalla is an example - he moved into control systems and telecom's) or simply elect not to share what they may have learned.
Ciao T
There's no evidence they've impeded progress - what they've done is just monopolize the mainstream channels for reporting it. Progress continues, 'off balance-sheet' so to speak. Are you not one who is benefitting financially from the lack of public presentation of audio progress?
Hi,
That monopolization coupled to a notable censorship of ideas has definitly impeded process, by reducing available channels of communication and by driving researchers into other areas of endeavour.
I am not sure I am benefiting from the lack of publication, I would rather argue that I am disbenefited by it just like the whole industry is.
For example, knowing a lead designer of DAC's and ADC's at Cirrus Logic, I have discussed with him the various concerns and considerations when a new chip is designed. Sound Quality is not a subject, just meeting certain specific and limited specifications, which lack any proven or reliable positive correlation with sound quality. Equally, competitors tend to focus on the same specific measurements and use them for promotion of their products, so the impact is felt all across semiconductor industry.
Without the accounting for sound quality (as it is believed to be determined by those few key measurements) we find that the wide ranging application of the resultant products (from recording equipment to iPod's and iPhone's) not only limits the ability of the small High End Audio segment to provide products of exceptional sonic merit, it limits the quality of recording equipment and thus of the recorded music and in ways that is not recoverable with any post processing and it sets the standards of reproduction expected.
So the impact is felt across a wide range of areas and overlapping magisteria, is applied permanently to the documented/recorded body of music and in my view is severely dis-beneficial to all of them.
Ciao T
That monopolization coupled to a notable censorship of ideas has definitly impeded process, by reducing available channels of communication and by driving researchers into other areas of endeavour.
I am not sure I am benefiting from the lack of publication, I would rather argue that I am disbenefited by it just like the whole industry is.
For example, knowing a lead designer of DAC's and ADC's at Cirrus Logic, I have discussed with him the various concerns and considerations when a new chip is designed. Sound Quality is not a subject, just meeting certain specific and limited specifications, which lack any proven or reliable positive correlation with sound quality. Equally, competitors tend to focus on the same specific measurements and use them for promotion of their products, so the impact is felt all across semiconductor industry.
Without the accounting for sound quality (as it is believed to be determined by those few key measurements) we find that the wide ranging application of the resultant products (from recording equipment to iPod's and iPhone's) not only limits the ability of the small High End Audio segment to provide products of exceptional sonic merit, it limits the quality of recording equipment and thus of the recorded music and in ways that is not recoverable with any post processing and it sets the standards of reproduction expected.
So the impact is felt across a wide range of areas and overlapping magisteria, is applied permanently to the documented/recorded body of music and in my view is severely dis-beneficial to all of them.
Ciao T
I think you credit the ideas monopolists with power way beyond their means. How does (say for argument's sake) a monopoly over the papers published in AES reduce the availability of other communications channels? I just cannot see it myself. Also I can't see how such a monopoly 'drives researchers' anywhere else - they just go under the radar in my experience. Passion (curiosity) drives original research and development and that can't actually be pent up for long, it always finds an outlet. Oftentimes actually encouraged by the establishment telling innovators that certain things 'just cannot be done'. That's a red rag to a bull
Well it does seem to be a characteristic phrase of yours that you don't wish for certain information to enter the public domain. If it was discovered and published by others then wouldn't you say your business (AMR) would suffer from increased competition?
Yep, that's obviously daft in the market you operate in is it not? So its a window of opportunity for your own products and services. If those designers were smarter, then you'd bave competition. As it is, the saying of economist David Ricardo comes to mind 'Profits are made by differential stupidy'.
I certainly see that as beneficial to my own business model. The more BS there is, the more brightly the truth shines
As long as one refuses to publish complete data and experimental methods, whether in academic journals or elsewhere, it's all just hype and marketing. As you point out, even if one accepts the rather ludicrous argument that a cabal of academics (unnamed) have closed the door to contrary results (asserted without any evidence), there are many, many other channels. Assuming one actually HAS solid data.
Hi,
I think I may not credit them with enough power.
As example, works that have been published in other channels (like Bateman's and Timmerman's work on different non-ideal capacitor effects) have remained obscure and ignored.
While this in part true, they may find themselves in want of resources (being published or not makes a considerable difference for funding) or just sufficiently disgruntled. I am aware of a number of cases of which Matti Ottalla may be one of the highest profile ones and Ragnar Lien possible a nearly as high profile a case.
Sure, however this outlet may be afar from Audio.
Much of the information I decline to disclose is either:
1) Full detailed schematics of some concepts - which I decline as they end up badly copied by Chinese vendors who fail to even understand how they work - I am usually quite free with my general comments.
2) Full or partial detailed schematics of commercial products I have designed - which I cannot offer even if I wanted to, as this would put in breach of contract.
3) Specific practical information, such as the precise manufacturer and series etc. of specific passive components - in part because these fall under trade secrets a and contractual obligation, in part because the knowledge may be useless, as the parts are not generally available.
I generally have been quite open about the general concepts that apply, though, as well as suggesting parts or methods available to DIYérs to attain similar results to as high a degree as using off the shelf items permits.
I wish your business success. We shall see if the truth indeed shall "set you free", as it says in the good book.
From my work in High End Audio I have not found this to be the case, even though I would wish for the contrary. I shall watch with interest.
Ciao T
I think I may not credit them with enough power.
As example, works that have been published in other channels (like Bateman's and Timmerman's work on different non-ideal capacitor effects) have remained obscure and ignored.
While this in part true, they may find themselves in want of resources (being published or not makes a considerable difference for funding) or just sufficiently disgruntled. I am aware of a number of cases of which Matti Ottalla may be one of the highest profile ones and Ragnar Lien possible a nearly as high profile a case.
Sure, however this outlet may be afar from Audio.
Much of the information I decline to disclose is either:
1) Full detailed schematics of some concepts - which I decline as they end up badly copied by Chinese vendors who fail to even understand how they work - I am usually quite free with my general comments.
2) Full or partial detailed schematics of commercial products I have designed - which I cannot offer even if I wanted to, as this would put in breach of contract.
3) Specific practical information, such as the precise manufacturer and series etc. of specific passive components - in part because these fall under trade secrets a and contractual obligation, in part because the knowledge may be useless, as the parts are not generally available.
I generally have been quite open about the general concepts that apply, though, as well as suggesting parts or methods available to DIYérs to attain similar results to as high a degree as using off the shelf items permits.
I certainly see that as beneficial to my own business model. The more BS there is, the more brightly the truth shines
I wish your business success. We shall see if the truth indeed shall "set you free", as it says in the good book.
From my work in High End Audio I have not found this to be the case, even though I would wish for the contrary. I shall watch with interest.
Ciao T
Thorsten, you are dead-on right! L&V virtually took over the JAES 30 years ago, and little has been published since, that is of real use to design engineers.
It should be remembered that the AES was FIRST started as an independent organization from the IRE, which perhaps was then full of 'learned' articles, and beyond the normal scope and capability of a typical good audio design engineer to prepare. I don't think that the IRE (now IEEE) welcomed the AES with open arms, either. So for about 30 years, we got good practical, and relatively complete papers from REAL audio design engineers, rather than just from academics, for the most part. Then things changed.
For example, Matti Otala's PIM paper, given first at an AES convention, was NOT allowed in the JAES. Why? Matti was told that the JAES was a 'journal of record' and controversial stuff like PIM, (even just the pure mathematics of it) were not considered suitable for the JAES. He reduced his output to the AES and finally even to the IEEE, which DID accept his paper at the time.
I was asked a few years ago why I did not participate in writing papers for the AES in recent years. I said that my ideas and efforts were not welcome at the AES anymore, and that I could not, like most of my colleagues, get a paper published in the JAES anyway. Not anymore. And so it goes!
It should be remembered that the AES was FIRST started as an independent organization from the IRE, which perhaps was then full of 'learned' articles, and beyond the normal scope and capability of a typical good audio design engineer to prepare. I don't think that the IRE (now IEEE) welcomed the AES with open arms, either. So for about 30 years, we got good practical, and relatively complete papers from REAL audio design engineers, rather than just from academics, for the most part. Then things changed.
For example, Matti Otala's PIM paper, given first at an AES convention, was NOT allowed in the JAES. Why? Matti was told that the JAES was a 'journal of record' and controversial stuff like PIM, (even just the pure mathematics of it) were not considered suitable for the JAES. He reduced his output to the AES and finally even to the IEEE, which DID accept his paper at the time.
I was asked a few years ago why I did not participate in writing papers for the AES in recent years. I said that my ideas and efforts were not welcome at the AES anymore, and that I could not, like most of my colleagues, get a paper published in the JAES anyway. Not anymore. And so it goes!
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Yeah, it sucks when you actually have to come up with data and have it withstand peer review.
I remember a few years ago when you were floating this conspiracy nonsense and I asked if ANYONE had submitted papers to JAES and had them turned down. Two people answered. On questioning, it turned out that one of them was not a paper, but a letter to the editor, the other was a paper that the reviewers found to be wrong, and the author was quite satisfied that he HAD made a mistake and they found it.
Yeah, especially when they quibble about definitions of 'overdrive' vs 'overload' (as they did with one of Matti's early papers). OR you write about something that they don't approve of, like hidden factors in making better audio equipment.
At my IEEE talk in 1978, Walt Jung and I met up with a 'peer reviewer', Dr. Ashley, in Tulsa, OK, USA. Walt Jung asked WHY his papers on 'SID' were rejected by him for publication in the JAES. Dr. Ashley said that he was 'suspicious of the math' especially regarding Volterra series calculations that were apparently put in by one of the authors.
Walt's co-author who put the Volterra series calculations was then an engineer at Sound Technology, and he learned Volterra series in the same class as I attended at UCB, taught by Dr. Don Pederson, (considered the father of SPICE) in 1973.
You would think that a peer reviewer would have to JUSTIFY his opinion, before rejecting a paper, but OH NO!
And so it goes!
At my IEEE talk in 1978, Walt Jung and I met up with a 'peer reviewer', Dr. Ashley, in Tulsa, OK, USA. Walt Jung asked WHY his papers on 'SID' were rejected by him for publication in the JAES. Dr. Ashley said that he was 'suspicious of the math' especially regarding Volterra series calculations that were apparently put in by one of the authors.
Walt's co-author who put the Volterra series calculations was then an engineer at Sound Technology, and he learned Volterra series in the same class as I attended at UCB, taught by Dr. Don Pederson, (considered the father of SPICE) in 1973.
You would think that a peer reviewer would have to JUSTIFY his opinion, before rejecting a paper, but OH NO!
And so it goes!
Ignored in the mainstream no doubt. But I'm aware of some of Bateman's work on capacitors so he's not been completely ignored.
Only resources that regard the mainstream view as some kind of authority. I was just this evening dipping into the biography of Steve Jobs - certainly he wasn't a published authority in computer science or EE but managed to drum up funding for his business interests. As ever, where there's a will, there's a way.
I've entered into this discussion with you previously on this forum and so won't re-iterate my arguments against it here. Needless to say its just as unconvincing as last time it came up.
Yes indeed you are one of the most helpful 'authority' figures on this forum. No doubt about that.
Indeed we shall - its kind of an experiment as much as it is a business.
Well as it also says in the good book 'No-one puts new wine into old wineskins' - it does seem to me that's one of the errors you're (plural, referring to your company) making in the way your particular business is being run.
@John:
OK, now we're getting somewhere.
As you know, I write papers for peer-reviewed journals, so have some familiarity with the process. So "Walt Jung asked WHY his papers on 'SID' were rejected by him for publication in the JAES. Dr. Ashley said that he was 'suspicious of the math' " seems odd- if a paper is rejected (or needs revision before publication), the referee comments are sent to the authors. This is the case with JAES. So Jung would have already known why the paper was rejected. And authors can either revise the paper in light of the referee comments or explain to the editor (who will have the explanation vetted as well) why the author believes that the referee is mistaken. If the paper is judged unsuitable, the authors have the option of submitting elsewhere. Of course, sometimes a paper is just wrong and the author(s) are too stubborn to admit it. "Help, help, I'm being suppressed!" is a cheap excuse.
If I compare my last submitted paper (nothing to do with audio) to the one that actually appeared in print, there were some significant differences- I think the final one was a stronger paper because of the tough refereeing. I didn't agree with everything the referees said and argued vigorously with the editor, but everything worthwhile takes effort.
OK, now we're getting somewhere.
As you know, I write papers for peer-reviewed journals, so have some familiarity with the process. So "Walt Jung asked WHY his papers on 'SID' were rejected by him for publication in the JAES. Dr. Ashley said that he was 'suspicious of the math' " seems odd- if a paper is rejected (or needs revision before publication), the referee comments are sent to the authors. This is the case with JAES. So Jung would have already known why the paper was rejected. And authors can either revise the paper in light of the referee comments or explain to the editor (who will have the explanation vetted as well) why the author believes that the referee is mistaken. If the paper is judged unsuitable, the authors have the option of submitting elsewhere. Of course, sometimes a paper is just wrong and the author(s) are too stubborn to admit it. "Help, help, I'm being suppressed!" is a cheap excuse.
If I compare my last submitted paper (nothing to do with audio) to the one that actually appeared in print, there were some significant differences- I think the final one was a stronger paper because of the tough refereeing. I didn't agree with everything the referees said and argued vigorously with the editor, but everything worthwhile takes effort.
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