John Curl's Blowtorch preamplifier part II - Page 1501 - diyAudio
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Old 15th August 2011, 07:29 PM   #15001
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Quote:
Originally Posted by ThorstenL View Post
Hi Jan,



Not quite. Your originally wrote in the original post:



To me this writing signifies that according to your testing "the best ones out there have no audible difference between their input and output signals".

It it merely expresses a belief, not rooted in actual experiment, as it now appears, than I am forced to disagree at this time with your contention, for lack of actual and tested evidence.

It is noble a belief to hold, for sure, I tend to be much more circumspect in my beliefs.

Ciao T
So, unless I proof it to you, you do not belief that there exist amps that have no audible difference between input and output? Even if I haven't proven it, you still may belief that it is true of course. Or maybe you are undecided so far? (An entirely logical position).
But do you at least belief that if they would exist, that would be an 'ideal' amplifier as far as faithfull reproduction is concerned?

jan didden
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Old 15th August 2011, 07:57 PM   #15002
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Jan,

Quote:
Originally Posted by janneman View Post
So, unless I proof it to you, you do not belief that there exist amps that have no audible difference between input and output?
Unlike others I do not reject anecdotal evidence.

So, if you told me that you had used a given method (preferably described) to compare input and out of a given (preferably identified) Amplifier and found no difference, I would see no reason to doubt your statement.

Even if you told me your maiden aunt's third cousin had done such a test and you therefore concluded the contention to be true, I would not doubt as such your statement, though I may downgrade the potential for accuracy from tripple A to single C...

However, if you make a definite and positive statement, such as "the best ones [amplifiers] out there have no audible difference between their input and output signals." without presenting any evidence, without even claiming to have done suitable experiments, forgive me for doubting that your statement was based in fact.

Thus your contention that "

Quote:
Originally Posted by janneman View Post
Even if I haven't proven it, you still may belief that it is true of course. Or maybe you are undecided so far? (An entirely logical position).
I have little use for the religious mode of the human mind which relies, as Saul of Tharsus so charmingly put it "the substance of things hoped for, the evidence of things not seen."

It has been my personal experience so far that no such amplifiers exist. So I am neither believer, nor disbeliever, nor undecided.

I am decided that until I receive better evidence than I had so far I hold the existence of such an amplifier as theoretically entirely possible (just as the Higgs Boson is theoretically possible), yet unproven as of now.

Quote:
Originally Posted by janneman View Post
But do you at least belief that if they would exist, that would be an 'ideal' amplifier as far as faithfull reproduction is concerned?
If it was coupled with loudspeakers that also where 'ideal' in the sense of your original contention in my living room and when reproducing recordings made "ideal' microphones and electronics, etc., most certainly.

Sadly, such 'ideal' devices or entities have so far failed to materialise in the realm of human experience (not just in audio) and at some point in time in the past where considered to exist only in the "mind of g*d" (whatever this may signify). As to many Humans the concept of a supranatural or superior being is depreciated we may say that such ideal entities only exist in the realm of Philosophy and Science Fiction novels.

Should, against my better judgement such ideal entities of any kind materialise in the realm of human experience (even if not audio related) do be sure to alert me...

Ciao T
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Old 15th August 2011, 08:00 PM   #15003
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Quote:
Originally Posted by john curl View Post
Tube amp with no GNFB
Ok, but which tube amp with no GNFB is the best you've ever heard ? It can be one or several if there's no clear winner.
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Old 15th August 2011, 08:04 PM   #15004
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Quote:
Originally Posted by Joachim Gerhard View Post
The best amps i ever heard are the Audionet Max and The Vacuum State KT88. They could not be different. The Max uses gobs of feedback and measures extremely well with nearly 1000W on tab into 2 Ohm. The Vacuum State is a zero NFB diffential design and the late and great Allen Wright told me that he had not even measured distortion during development. He was not interested in things like that. It was dead quiet though on my 100dB sensitive speakers and rather wideband and high power ( 4 x KT88 per mono block ). The Max sounds extremely accurate and pristine but without being harsh. There is a nothingness to sound that my classical oriented audiophile friends find irresistable. They tell me that they can follow the partitur to the nth degree. It throws a big stage if its on the record. I can hear no loss of micro detailing and that was also reported from the ones that use it in other systems. Allens amp is something different. It does not analyse the music. It simply playes the music in such a beautifull and mesmerising way that you simply forget in a minut that you are listening to your HiFi.
Pick your poison.
Thanks, an opinion supported by arguments - that's exactly what I was hoping for !
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Old 15th August 2011, 08:08 PM   #15005
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Quote:
Originally Posted by Joachim Gerhard View Post
The best amps i ever heard are the Audionet Max and The Vacuum State KT88.
I tried searching for "The Vacuum State KT88" but without success.
Can you point me to a link about it ?
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Old 15th August 2011, 08:33 PM   #15006
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Quote:
Originally Posted by janneman View Post
But do you at least belief that if they would exist, that would be an 'ideal' amplifier as far as faithfull reproduction is concerned?
Jan, I'm not as shy as Thorsten, so I'll say "Yes". But I would want to see the amps measured on the load they will be driving and see FR, crosstalk, a good spectrum analysis at least every octave from 20Hz-12Khz and some IM measurements as well. Impulse would also be nice to see. If the inputs and outputs look alike on with all that, I'd be super happy.

But I'm willing to bet that 2 amps can sound almost exactly alike and still fail some of the above tests. Some stuff just isn't that important to the ear. I wish I knew better what.
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Old 15th August 2011, 08:54 PM   #15007
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I don't think that a simple difference test will tell us much, either.
Just look at the results of a SINGLE capacitor, compared to a higher quality capacitor, such as a 1uF Teflon in the test that Walt Jung and I did, back in 1985 or so.
A single Mylar cap could give you a -70dB residual, even with compensation for inductance, resistive ESR, and value differences. How can a complete power amp, especially with input coupling caps do any better?
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Old 15th August 2011, 09:02 PM   #15008
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Quote:
Originally Posted by john curl View Post
Tube amp with no GNFB

Quote:
Originally Posted by Joachim Gerhard View Post
The best amps i ever heard are the Audionet Max and The Vacuum State KT88. They could not be different. The Max uses gobs of feedback and measures extremely well with nearly 1000W on tab into 2 Ohm. The Vacuum State is a zero NFB diffential design and the late and great Allen Wright told me that he had not even measured distortion during development. He was not interested in things like that. It was dead quiet though on my 100dB sensitive speakers and rather wideband and high power ( 4 x KT88 per mono block ). The Max sounds extremely accurate and pristine but without being harsh. There is a nothingness to sound that my classical oriented audiophile friends find irresistable. They tell me that they can follow the partitur to the nth degree. It throws a big stage if its on the record. I can hear no loss of micro detailing and that was also reported from the ones that use it in other systems. Allens amp is something different. It does not analyse the music. It simply playes the music in such a beautifull and mesmerising way that you simply forget in a minut that you are listening to your HiFi.
Pick your poison.
Both statements ring a true to me.
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Old 15th August 2011, 10:10 PM   #15009
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In this newsletter you find the Vacuum State amp i am talking about. Actually the name is DPA150 but i am bad in remembering numbers. For me it is simply the Allen Wright KT88.
http://www.vacuumstate.com/fileuploa..._2010_Comp.pdf
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Old 15th August 2011, 11:12 PM   #15010
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Quote:
Originally Posted by Joachim Gerhard View Post
In this newsletter you find the Vacuum State amp i am talking about. Actually the name is DPA150 but i am bad in remembering numbers. For me it is simply the Allen Wright KT88.
http://www.vacuumstate.com/fileuploa..._2010_Comp.pdf

Thanks, I'll take a look.
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