John Curl's Blowtorch preamplifier part III

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@ PMA,

OAE and SOAE are happening in every healthy "ear" (in fact they indicate that the OHCs are in good working shape) - so to state that tinnitus is caused by these isn´t afaik corrobated by experimental studies.

Instead there is evidence that (S)OAEs are less prevalent for certain types of tinnitus.

Yes, that was my understanding from the link he posted :confused:
 
What can I say, other than quoting:
I see you can't provide any links to back up your claim about obtuse research papers or ones which experts argue over
Again, you present just a rant & when asked for some backing you demur
Obviously you can't say anything as you are bereft of logical debate, just inchoate rantings.
 
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And now just try to link to this fascinating thread over at Hydrogenaudio Forums - Index so that people can decide if it did only happen in your imagination or indeed in this reality. ;)

I did find this interesting tidbit over there.

"Reminds me of little Johnny's contention about ABX "false positives" and Arny resorting to diabolical cheating by merely guessing.
He posts as mmerrill99 and lord knows who else on other fora these days.
As greynol suggested, rinse and repeat"
 
This is the alleged business Merrill Audio Advanced Technology Labs, LLC. "Audio Purity" TBH I find it hard to believe that someone apparently into sighted listening tests would be responsible for such cheesy looking equipment :D
Huh......I wouldn’t know enough about high end stuff like that to make any intelligent comments except it’s way above my diminishing return threshold :p

I wouldn’t refuse a free one, wait a minute.....class D? I suppose I could fire my subs with it:D
 
Let´s take it serious for a moment, as I told and recommended a lot of these thinks back in 2009, before you were taking a break.

Be honest, for all these years, you´ve never conducted some controlled listening tests with other people, you haven´t tried any of my suggestions and you haven´t read any of the publications i´ve cited, correct?

Ok, I'll bite; please point me to any of these complete test plans, I must have missed it; "suggestions" and "recommendations" won't cut it. I don't feel like playing hide and seek, so it's either a complete and coherent test case and plan, or it is not.

No, I'm not in that business, I don't have neither the resources or the interest in doing such tests. That's why I asked for a test plan "that anybody could independently reproduce and verify". Or what about you showing some of your results? Wait, they must be confidential, so not an option, isn't it?
 
Jakob, would you kindly teach me what would be the smallest detectable L/R ITD for an onset impulse signal? Thank you.

I´m not sure if i understand the question, as the term "ITD" already refers to "L/R"?

In general, at the moment i´d consider experiments using pulse-trains to be in the "onset group".
In fact Nordmark was the one with lowest reported ITD´s detected by his participants in the case of jittered pulse trains. (using headphones)

When using loudspeakers, the numbers are usually higher (one possible reason, i.e. the reflections i´ve mentioned before) and i´ve to search if there were experiments done using pulse-trains.

Overall it is nearly impossible to answer, as there is strong dependance of SPL and other conditions, namely the training effect.
 
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Ok, I'll bite; please point me to any of these complete test plans, I must have missed it; "suggestions" and "recommendations" won't cut it. I don't feel like playing hide and seek, so it's either a complete and coherent test case and plan, or it is not.

No, I'm not in that business, I don't have neither the resources or the interest in doing such tests. That's why I asked for a test plan "that anybody could independently reproduce and verify". Or what about you showing some of your results? Wait, they must be confidential, so not an option, isn't it?

Psycho-acoustics is a huge field. Lots of experiments going on and lots of results - typical of the psychology world. I don't think you can get a 'clear' answer and you have to sift through a lot of data and arrive at your own conclusions. I'd say its a field that is less understood than audio amplifier design as of 2019.

I think Jakob just brings an alternative view that should be considered - he references/cites papers about what we know in that field. All we can do as amplifier designers is make them distort as little as possible (or distort in a nice euphonic way).


I have on my bench right now a solid state amplifier that produces not less than 0.02% t (2nd, 3rd, 4th and just hint of 5th) at near full output power. For most of its output, its produces 2nds and 3rds and above 20 Watts the distortion is never less than 0.01%. It sounds organic and smooth in a way my ultra low distortion designs do not - I have no clue why but I am sure its not to do with the absolute distortion levels.


My point is, when it comes to distortion, single digit ppm only tells you how well the amplifier was engineered. It will for the most part - given similar output levels, frequency response, load drive capability - not determine the quality of the listening experience.

I am an objectivist - so I do measure and I try my best to make sure there are no blatant engineering errors - and I do not claim things that don't stand up to scrutiny.

:)
 
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Psycho-acoustics is a huge field. Lots of experiments going on and lots of results - typical of the psychology world. I don't think you can get a 'clear' answer and you have to sift through a lot of data and arrive at your own conclusions. I'd say its a field that is less understood than audio amplifier design as of 2019.
It's more complex than amplifier design but is also intimately connected to the end product of what is produced by our playback systems - a recreation of a soundstream that is believably real

I think Jakob just brings an alternative view that should be considered - he references/cites papers about what we know in that field. All we can do as amplifier designers is make them distort as little as possible (or distort in a nice euphonic way).
I'm not sure that's all that can be done considering your next couple of paragraphs


I have on my bench right now a solid state amplifier that produces not less than 0.02% t (2nd, 3rd, 4th and just hint of 5th) at near full output power. For most of its output, its produces 2nds and 3rds and above 20 Watts the distortion is never less than 0.01%. It sounds organic and smooth in a way my ultra low distortion designs do not - I have no clue why but I am sure its not to do with the absolute distortion levels.


My point is, when it comes to distortion, single digit ppm only tells you how well the amplifier was engineered. It will for the most part - given similar output levels, frequency response, load drive capability - not determine the quality of the listening experience.

I am an objectivist - so I do measure and I try my best to make sure there are no blatant engineering errors - and I do not claim things that don't stand up to scrutiny.

:)
I'm not arguing with you but you have made a claim that many would jump on if you weren't who you are - namely, " It sounds organic and smooth in a way my ultra low distortion designs do not"

I hardly need to remind you what the stock reply to this claim is & how the narrative usually progresses from there?
 
Its euphonic Merrill - it does sound good. As do the ultra low distortion ones.

So where does that leave us?

I don’t understand what the problem is with using adjectives to describe a character sound of a piece of equipment......even if 10 people use 10 different words there’s usually going to be commonality enough to paint you a picture.

When we buy a piece of audio gear nowadays it’s usually mail order without a demo......specs only tell that it’s designed well like bonsai said.

And for those that say if your amp sounds different it’s defective I say...BS.

Everything I own has a different sound that even differs more depending on what’s connected to it.

Good to see one of the respected ‘pros’ describing sound.
 
What business is it that Merrill is in.....if you can’t post it for the rules of ‘spam’ or whatnot please somebody pm me so I know what’s continually being referenced?
If you look at upper right corner of the forum page, it shows "Search" and an arrow symbol, when you left click that arrow symbol, it gives you an option to "Advanced Search". If not, you should contact the forum tech staff or your internet provider and find out what's wrong.

And now just try to link to this fascinating thread over at Hydrogenaudio Forums - Index so that people can decide if it did only happen in your imagination or indeed in this reality. ;)
Why not link the search result of posts by "Jakob1863"?

Wrt "audio business issues" , you can´t have it both ways. You´ve recommended reading Peter Aczel´s opinion paper (despite the factual flaws in some paragraphs) although he was in the audio business (and afair forgot to disclose that he was (co?)owner of the manufacturer which produces the loudspeaker he raves about in a review).
I've stated many times that speakers (& room acoustics) are the bottleneck in audio replaying electronics. Speakers do vary sound greatly and have been demonstrated in double blind tests.
 
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