John Curl's Blowtorch preamplifier part III

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This DAC is a gift and I don't have money to buy better one.
Don't worry about it. What you have is better than your ears can detect. Others who dwell on better DAC don't understand the audibility aspect of it. They only go by their belief, not proof.
Next project? I don't have enough knowledge in that area to put my fingers in it.
Improve the room acoustics. Try that title search on this forum and you will get tons of info.
 
While J.C., with all my sympathy, continues to imagine his own furniture build by hand with pieces of wood from another age, I am aware that, on my own, I have passed from discrete components, assembled by me ... to integrated circuits, then to pre-assembled cards with SMDs that I can only see with difficulty.
...
I can die in peace.

Well, there are those who have reached Nirvana, and those who are still trying.

A few years ago, my tubed MC pre-preamp died of exhaustion, because I accidentally plugged it in an always-on AC instead of a switched one, so it's been running continuously for 10 years or so.

I swapped in a mckinnie pre-pre designed by JC in the 70's: it sounded good, cleaner and more refined than my crude tube unit, but lacks the 3D effect that I miss. Last year, the mckinnie died of a yet unknown cause, I hope it's the 'lytics, so I swapped back the tube unit after replacing the ECC88/6DJ8. The magic is back.

With due apologies to JC, I prefer the sound of vacuum. Neither unit does anything wrong, technically: the tube unit has about .05% THD at .3Vpp out and 1KHz and 20KHz. I haven't measured the mckinnie, but it's a JC-standard complementary JFet/folded cascode topology. But the difference is clearly audible. And yes, it's a sighted test, because it's a 1 dead 1 alive case.
 
When i hear somebody telling: don't listen to recordings, go to a live concert, much better experience! i just feel like laughing...the whole world is a fabrication, out fifth opposable finger that made the violin is a nature fabrication, the future AI that will replace us is a nature's fabrication...we are just slaves of the technology, not the other way around .We can only escape in our past nature , extending the time scale and go backwards!
There's nothing interesting in the future for us, cause future is always replacing us with new...US!


I understand JC a lot...living in the past is actually the best thing we can do for ourselves.
Just don't sell it too high cause i don't want to go again in the future to pay for an expensive past!
I cannot agree more.
About your first sentence: "go to a live concert", some *personal* thoughts.

For guys that only listen to classical music, you could say: Don't go to live concerts, play yourself ;-)

For the others, and as an ex sound engineer, I just can say that, nowadays, the record is, most of the time, the original creation, and that live performances are, on a sonic point of view, very degraded copies of it. (Taking apart this mysterious exchange between audience and musicians).
A record is not a reproduction of any reality but a complete process of creation.

When I hear this sentence, I always want to answer, in an ironical way: "Don't go to the movies, fight the martians yourselves".

This is all about this endless war, here, between the "objectivists" and the "subjectivists", that makes so many victims.
Objectivists believe in some accuracy (High fidelity), while the others only try to improve their pleasure.
That makes the ones believing in numbers, and the other, in their ears.
With all the nuances in between.

What is interesting in this question is that the quest of High fidelity is in the tradition of "His master voice". A quest from an old age.
The most faithful system to listen to a record is not using a 0.0001% distortion amplifier, but the closest copy of the flawed system that was used to mix-it ... because everything was based on it.
 
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The most faithful system to listen to a record is not using a 0.0001% distortion amplifier, but the closest copy of the flawed system that was used to mix-it ... because everything was based on it.
Which of the copies after a 30inch/sec master tape will be better: a vinyl or a digital one?I think that only the modern digital can preserve the true value of a tape recording.On the other hand some master tape records might be in a too bad shape after 30...50 years, and the only way is to get it from the vinyl master.Now ...the vinyl that they bought in store is inferior to the positive master steel pressed vinyl which is again another copy of the negative first vinyl...
What's really bad is that no cartridge can read the information on vinyl in full.
Laser vinyl and AI assisted video reading of the vinyl(Philips way) is the only way to get as much information as it could be stored on vinyl.
 
Which of the copies after a 30inch/sec master tape will be better: a vinyl or a digital one?I think that only the modern digital can preserve the true value of a tape recording.On the other hand some master tape records might be in a too bad shape after 30...50 years, and the only way is to get it from the vinyl master.Now ...the vinyl that they bought in store is inferior to the positive master steel pressed vinyl which is again another copy of the negative first vinyl...
What's really bad is that no cartridge can read the information on vinyl in full.
Laser vinyl and AI assisted video reading of the vinyl(Philips way) is the only way to get as much information as it could be stored on vinyl.
+1
I adopted the digital because it was hard to distinguish a digital copy of a master from the original, while, with an analog tape copy, the difference was obvious.
And that, while the sound slowly deteriorate on an analog tape at each re-recording, friction on the heads (wear of the magnetic surface, magnetization, even when you take great care of it), the digital keep your original sounds unchanged, whatever the number of time you are listening to it.
Vinyl ? When you listen to a customer vinyl of one of your masters, you can only... cry.
 
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Of course.
This said, if controlled listening test are useful for scientific statistical studies, what their need in the process of voicing a gear during a design work of an audio product ?

As usual it depends on the specifics; if "voicing a gear" means to meet a specific sound target (that is diverging from being neutral/transparent) then it is a different situation compared to trying for reaching neutrality/transparency.
But in any case it is additionally a matter of trust; quite frequently other fields - using sensory tests - an expert is asked and if this experts says the different is really small then the more sophisticated controlled sensory tests come into play.

When differences between two solutions are obvious, no need to "controlled listening tests". (Like blind or ABX)
When they are not, we need-it and... use it. (to chose a component, by example, but... the question of the quality / price ratio will arise first)

The differences we are talking about in these threads are often described as "obvious" (which is a term that is difficult to quantify) while other think this "obvious" difference doesn´t exist at all (not even a not so "obvious" difference, means no difference).
As the latter hypothesis is based on a specific model (using the known thresholds of hearing and often masking theory) it is a reasonable hypothesis and should not be dismissed easily.

-Controlled listening tests are complicated and tiring. And those complicated procedures and the fatigue they cause tend to decrease our sensibility. So the result will often do not learn us much more.<snip>

Often they are complicated and tiring, sometimes even costly, but nobody prevent an experimenter from being creative.
Use the experiences from those mentioned other fields, enhance/modificate for the special needs of listening tests; try to use a combination of qualitative and quantitative methods as a possibility to overcome the "fatigue" .

<snip>
See what I mean on a philosophical and political point of view ?[/I]

Sure, but that is a totally different topic. 😉
 
<snip>
The most faithful system to listen to a record is not using a 0.0001% distortion amplifier, but the closest copy of the flawed system that was used to mix-it ... because everything was based on it.

Although i´ve often stated something similar, there certainly is a distinction between a workplace (what a production environment most often is) and "living place" that is used -within other activities- to listen to music also.

Very different requirements (might be the reason why people involved in the production of music quite often don´t use the studio equipment at home)often It could be that the reproduction system used in the mastering step would be the better alternative for listening at home.
And given the intersubject differences for some people something completely different might be the best solution.

All said under the assumption that the production was aiming for high sound quality.....
 
So you don't have a proof of "that" quoted. Thanks for confirming my suspicion.

If you had asked for a proof for "2 + 2 = 4" I would have in a similar way by encouraging you to read some good literature about proofs in mathematics.

Your thoughts about "confirming my suspicion" is just a misguided conclusion.

I asked him about sound, not things or perception.
As you don´t know if he was talking about sound or perception, you shouldn´t have asked that question in a way implying that it could have been only your interpretation.

Zung can stand his own without your assistance, no?

I´m sure Zung can, but you were posting in a public forum and so others can chime in.
If you don´t want that you should try the PM system.

<snip>
Distraction in listening to audio electronics is the visual sense mixing in with aural sense when doing sighted comparison.

Sure, can be; it is a known confounder .....
To think it is the most important one is a misguided conclusion.

How often do you see people posting "heard no difference" in "sighted listening" compared to "heard a difference"? Since you've made the observation, you would know.

As you´ve cited my statement you should have noticed that these are different topics, so obviously your "Since ....." part is a misguided conclusion.
Something like this happens quite frequently on your part, so you should read up about logic.

Or are you just using the playbook of eristics?
 
-Controlled listening tests are complicated and tiring. And those complicated procedures and the fatigue they cause tend to decrease our sensibility. So the result will often do not learn us much more.
"4. The Listening Test Lie
The standard tweako objections to ABX tests are too much pressure (as in "let's see how well you really hear"), too little time (as in "get on with it, we need to do 16 trials"), too many de-vices inserted in the signal path (viz., relays, switches, attenuators, etc.), and of course assorted psychobabble on the subject of aural perception.
"

How did late Peter Aczel know what Tournesol from Belgium is going to say over 18 years ago? That's because it's the old worn out red herring fallacy used for many years.
 
... pre-pre designed by JC in the 70's: it sounded good, cleaner and more refined than my crude tube unit, but lacks the 3D effect that I miss. Last year, the mckinnie died of a yet unknown cause, I hope it's the 'lytics, so I swapped back the tube unit after replacing the ECC88/6DJ8. The magic is back.

With due apologies to JC, I prefer the sound of vacuum. Neither unit does anything wrong, technically: ...
Another supposedly measurable stuff lacking coherent comprehension with discussions often met with negative remarks. 🙂
 
If you had asked for a proof for "2 + 2 = 4" I would have in a similar way by encouraging you to read some good literature about proofs in mathematics.

Your thoughts about "confirming my suspicion" is just a misguided conclusion.
You didn't post any proof. You posted your opinion.
As you don´t know if he was talking about sound or perception, you shouldn´t have asked that question in a way implying that it could have been only your interpretation.



I´m sure Zung can, but you were posting in a public forum and so others can chime in.
If you don´t want that you should try the PM system.



Sure, can be; it is a known confounder .....
To think it is the most important one is a misguided conclusion.



As you´ve cited my statement you should have noticed that these are different topics, so obviously your "Since ....." part is a misguided conclusion.
Something like this happens quite frequently on your part, so you should read up about logic.

Or are you just using the playbook of eristics?
Usual deflection noted.
 

I´m sorry to bring bad news but Peter Aczel simply did not know a lot about the pitfals of controlled sensory tests in general and the ABX test in specific.

As there exists sufficient evidence (often already cited in other threads) that different test protocols provoke "stress" effects in different ways you should stop fooling yourself about the merits of the opinion paper that you´ve cited above........
 
I´m sorry to bring bad news but Peter Aczel simply did not know a lot about the pitfals of controlled sensory tests in general and the ABX test in specific.
In your opinion. I heard that you are in audio business.

As there exists sufficient evidence (often already cited in other threads) that different test protocols provoke "stress" effects in different ways you should stop fooling yourself about the merits of the opinion paper that you´ve cited above........
Not relevant evidence but pinion and conjecture often already cited.
If stress debilitates your hearing ability, just take your time do little at a time as Peter suggested.
 
You guys have been busy over the last 12 hours.
First, I would like to say, that my BEST hi fi system, (the one I play only seldom) is all discrete, either solid state, or tubes. The problem starts when I try to introduce digital into it with CD, SACD or even Blue Ray. There is where it falls down, and I will seldom listen to digital sources for pleasure.
Now when I scale down to a set of Sequerra Met 7's, then I can listen to digitized sources relatively comfortably, as I do most of the time, but I don't consider it really hi fi.
You are right, Jakob2 in the problem with ABX listening tests, don't led Evenharmonics get to you. He is just a troll, or at best, a 'Sophomore'.
I will continue for the rest of my days to design with mostly discrete parts, my audio designs, because the manufacturers that I work with have them in stock, so why shouldn't I? I have never found an IC that I truly love. They are all compromised, even today's latest designs.
I grew up with tubes and did not even design my first solid state power amp until I was 25 years old, and this early design (all class A and complementary) failed slightly against an early vacuum tube triode amp. I have been working to fix this discrepancy for more than 50 years, but I doubt I will ever completely achieve it. Tubes rule!
Zung, you bought a McKinnie? Did you buy it from Reza? (my former technician) It is a flawed implementation from my early work, and later Vendetta products have many improvements to make it better. Still, mostly it is VERY quiet, compared to tubes, not necessarily better sounding.
 
. We had no computers at all when I started it was pencil, paper, and HP calculators. We ran wafers of discretes on our process and built breadboards too. The masks were drawn and cut by hand at something like 500x .


Although I only started learning about this as rubylith went out (but we still had the cutters in the hp plotters at work), it's still quite sobering how the semiconductor industry literally pulled itself up by its own bootlaces through the 70s-90s. The whole concept of phase shift masks (luckily not generally needed for analog) scares me.
 
Still, mostly it is VERY quiet, compared to tubes, not necessarily better sounding.
Tubes can produce no audible noise up to a mm cartridge preamp and with the aid of an input transformer it stays the same with an mc cart too...I did hybrid phono preamps whith valves for voltage gain and bjt for current gain that had no audible noise without the cartridge attached(47 k) at max volume out...
Indeed , valves sound better, but need help either from transformers either from bipolars to drive low impedance filters for lower noise in the whole bandwidth.


I could make a living just out of countering your quotes...🙂
 
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... Tubes rule!
Zung, you bought a McKinnie? Did you buy it from Reza? (my former technician) It is a flawed implementation from my early work, and later Vendetta products have many improvements to make it better. Still, mostly it is VERY quiet, compared to tubes, not necessarily better sounding.

Nope, on eBay, from a guy in Biel, Switzerland; too good a deal to pass. It's got a sound I can live with, and I did just that happily for some time until it died. Not easy to fix with the bulk of its guts potted. Some voltages are off, and 1 'lyctics is shorted, so hopefully, it's only the external components that went bad.
 

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