John Curl's Blowtorch preamplifier part II

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Joshua,

While I understand the wish to select your projects on some kind of trustworthy listening result, your statement above cannot be easily resolved.
You agree that anecdotal listening reports from individual listeners don't say anything about what you would like or not, yet you don't want to select your amp unless there is a listening report.

Indeed, it cannot be easily solved.
Indeed, I cannot rely blindly on any listening reports.
However, there are some reports I trust more than others – though I can never trust any report blindly and fully. Different people have different taste and preferences concerning audio reproduction sets. Also, the overall sound of any piece of gear, an amp, for instance, is dependent on the rest of the setup, especially on the speakers and the room's acoustic.

You can't escape your own conclusion: you must somehow use other parameters to select maybe a few projects, and listen for yourself, with the risk that it's not what you want. And while I agree that measurements don't tell you how an amp sounds, I DO know that an amp that measures well in a few significant areas at least doesn't add too much or subtract too much from the music. I would think that this would be a good starting point.

My experience doesn't support your statement that "an amp that measures well in a few significant areas at least doesn't add too much or subtract too much from the music". No PP power amp that I heard, tubes or SS, had the amount of details and microdynamics of a SET amp, while SET amps measure far worse than most PP amps (in THD, IMD and SNR). SET amps are far from being perfect and I cannot live with their shortcomings, however, it is obvious that THD, IMD and SNR tests fail to give even an approximate picture of the sound quality of an amp.

Inevitably, unless you go for a finished product in a shop that you can audition, there's always the gambling element in a diy project to the outcome. Actually, the fact that we are so subjective and open for influence does help in this case: selecting a project that gets rave reviews increases the likelyhood that you too will like it.

Being retired, I don't have the money to buy good commercial amps.
From the reviews I read and from other data, I feel it wouldn't be much of a risk to build Allen Wright's published designs. Anyhow, it appears to me the best I can do in my present situation.
 
Again, if you have ANY actual data showing that ANYONE can hear the difference between a Blowtorch (or Ayre or whatever luxury unit) and a cheap IC opamp based linestage without peeking, I'm eager to see it.

I hear differences between different line stages, or preamps, without peaking. Would it be otherwise, I could save a lot of money. However, I'm not sure I can convince you. Actually, I'm not interested in convincing anyone. It's my money and my enjoyment of listening to reproduced music which I care about.
 
Gee, wasn't it you for whom I wrote a detailed protocol for a listening test (I think it was wires), at your explicit request, taking quite a bit of my time, just to have you then say that you weren't really interested in doing a controlled test?

No, it wasn't me for whom you wrote any detailed protocol.

If you haven't read my numerous posts about listening tests, methods, and controls, not to mention the custom-designed protocol you got from me, please read and understand them before totally making up things again. I realize that I'm not a great writer, but my stuff is reasonably understandable even to a non-native English speaker.

I didn't read all your posts.
It will make it easier should you post a link to relevant post(s) of yours.
 
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Yes, you'd have to read the whole thread to see the actual references to Doug's words.

As you say, I think we broadly agree, but my emphasis is much heavier against Audio Designers who do not give an account of listening assessment. I know that he makes useful remarks about certain design considerations, BUT, architecting an amp around what you can measure ONLY, is not good enough.[snip]

I don't know Rod; what if Doug Self would be waxing lyrical about the fantastic sound of his designs, would that help?
Or, would it convince you you'd absolutely want to build his design?
Chances are most people, probably including you, would fall over him for being prejudiced.

jd
 
I don't know Rod; what if Doug Self would be waxing lyrical about the fantastic sound of his designs, would that help?
Or, would it convince you you'd absolutely want to build his design?
Chances are most people, probably including you, would fall over him for being prejudiced.

jd

Jan, we don't need designers to tell us that their amps are better than the rest of the World. But I think it helps when Designers talk about the effect of design decisions on sound. OK, that's a personal thing perhaps. To show what I mean, try Lynn Olson's account of the decisions made in his amplifier design:

The Amity, Raven, and Aurora

This work has such a finely balanced blend of engineering AND perception.

Doug is the complete opposite of that, and only talks about problems that can be measured. And he has a whole section of his writings devoted to denying any place for subjective listening, which I regard as really negative and destructive. And is the main reason I don't take his ideas seriously.

As Lynn has said - audio design needs the measurement AND the listening experience. To leave out one of these is like flying blindly.
 
Indeed. Most psychoacousticians and other reasonable studied people would see a causal relationship here.

jd

Reasonable means different things to different people.
In this case, I see a guesswork on your part, rather than any actual knowledge. Your remark suggests that the differences I hear are in my mind, rather than in the amps themselves. You are wrong here, since I hear the differences even without knowing in advance which amp is playing at a given time.
 
This work has such a finely balanced blend of engineering AND perception.

Yes, I like Lynn Olson's approach too.

Doug is the complete opposite of that, and only talks about problems that can be measured.

Hardly the complete opposite, just unbalanced in the direction of trusting measurements and, apparently, not his ears.

And he has a whole section of his writings devoted to denying any place for subjective listening, which I regard as really negative and destructive.

To me its just rather quaintly self-satisfied and prejudiced.

And is the main reason I don't take his ideas seriously.

Its unreasonable to throw the baby out with the bathwater - your loss if you do.

As Lynn has said - audio design needs the measurement AND the listening experience. To leave out one of these is like flying blindly.

I'm not even sure that it actually does need the measurement myself, perhaps that's because I haven't bought myself an AP (yet):D. If it sounds good enough, what use are the measurements? And then, which measurements?
 
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Jan, we don't need designers to tell us that their amps are better than the rest of the World. But I think it helps when Designers talk about the effect of design decisions on sound. OK, that's a personal thing perhaps. To show what I mean, try Lynn Olson's account of the decisions made in his amplifier design:

The Amity, Raven, and Aurora

This work has such a finely balanced blend of engineering AND perception.

Doug is the complete opposite of that, and only talks about problems that can be measured. And he has a whole section of his writings devoted to denying any place for subjective listening, which I regard as really negative and destructive. And is the main reason I don't take his ideas seriously.

As Lynn has said - audio design needs the measurement AND the listening experience. To leave out one of these is like flying blindly.

I'm in Doug's camp. I appreciate a guy who can resist flogging his own stuff, and subjectively to boot.
Maybe I know too much about how this perception thing works, and too much about how people make decisions and make up their mind, (completely sincere of course) to put any value to someone's judgement of his own performance.

jd
 
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Reasonable means different things to different people.
In this case, I see a guesswork on your part, rather than any actual knowledge. Your remark suggests that the differences I hear are in my mind, rather than in the amps themselves. You are wrong here, since I hear the differences even without knowing in advance which amp is playing at a given time.

No its actual knowledge. Knowing how people make up their mind, what factors influence that.
And of course any differences or anything anybody hears or sees or feels are all in the mind, I hope we don't have to go back to those basics please.

jd
 
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