John Curl's Blowtorch preamplifier part II

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What we hear is what eventually leads to rigourous investigation. Would anybody bother measuring distortion if it was inaudible?

Clearly you have not bothered to read any of the works of Geddes, or any of the audibility tests on distortion. Of have you decided to hand wave those away as you do with everything else because you don't believe in DBLT?
 
Clearly you have not bothered to read any of the works of Geddes, or any of the audibility tests on distortion. Of have you decided to hand wave those away as you do with everything else because you don't believe in DBLT?

Have I ever said I didn't believe in DBLT?

More bad assumptions - and as usual you are more wrong than right. Ask me first, OK? Don't assume.

Waving? You are the one doing the waving. Real concerns are waved away, never addressed.

I state my concerns, my case is a reasonable one.

Would one of you guys ever address a single concern I have stated?


I will likely wait in vain...?

 
it's time to re-evaluate my general standards.

Maybe you should re-evaluate your designs ?

I have a lot of practical experience with Burr Brown and AD opamps.
(part because I pay €5 tops for back of the truck opamps as e.g. 627/637/797 in any battle dress, tried the first ones around '91 for 25 Dutchies/pc)
So not my impression.

In the words of Mr. Joachim Gerhard : it's the designer who knows what it does and how to use it !

(I may enjoy the milk that went through the cow udders, doesn't imply I'm the least interested in eating the nipples)
 
Maybe you should re-evaluate your designs ?

Obviously - if not, why would I even bother?

I have a lot of practical experience with Burr Brown and AD opamps.
(part because I pay €5 tops for back of the truck opamps as e.g. 627/637/797 in any battle dress, tried the first ones around '91 for 25 Dutchies/pc)
So not my impression.

To be expected, if you have worked a lot with them.
 
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Have I ever said I didn't believe in DBLT?

More bad assumptions - and as usual you are more wrong than right. Ask me first, OK? Don't assume.

Clearly you have not read the complete Ramblings of Rasmussen where you sway between 'agnostic' and that all tests are flawed so you will have no part of them. In between trumpeting 'just do it yourself in uncontrolled conditions then you will hear'.
 
Guys, you are not the holders of holy writ.

Of course not. That's why honest practitioners test their hypotheses. If a claim is made that A sounds different than B, and there's no obvious measurable reason, they use their ears (or the ears of others) to validate or falsify. Not their eyes, not their preconceptions, not their egos, their ears, and ears only.

I understand and sympathize that it's easier if one is genuinely curious and doesn't have a financial and/or ego stake in the outcome. But that's what separates out the hucksters and their dupes and shills- excuses about peeking, rather than actual listening.
 
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I am not the fanatic that you are.

Have you ever tried to play nice?

Dunno, ask other people on the forum. Sure plenty of them have emailed you saying how awful I am. And your Cop friend is possibly scared to come on line because of me.

Anyway its not fanatical to read the odd paper. Especially when its making a serious attempt to come up with a more useful metric for measuring quality in reproduced music.
 
Are there any existing vfa or cfa IC amps which would allow access internally to the Vas - before the OPS? Such that a separate OPS could be used and no signal the IC OPS? Better yet also be able to disable the OPS?
As much of the IC OPA CFAs are both very fast (~1000V/µs) and working with low impedance feedback networks (~1K), I believe their current ability will not be a problem, and they usually will not even see the additional load in Audio.
You can usually add a discrete buffer to their OPS included in the feedback loop with no fear of a limited bandwidth.
 
If a claim is made that A sounds different than B, and there's no obvious measurable reason, they use their ears (or the ears of others) to validate or falsify. Not their eyes, not their preconceptions, not their egos, their ears, and ears only.
Several remarks.
I (I don't know for you) don't have a plug at the output of my ears, to make measurements. So I'm obliged to use ears+brain, and not "ears only".
Second, As I never found two active devices witch measured the same, not to speak about complete amplifiers, and as you were never able to teach-me where are my thresholds of audibility for harmonics, micro dynamic, mask effects, phases rotations, room reflections variations of the frequency curve depending of the source direction (I can add hundreds) there is no point where i can say: "Here we are", let's concentrate on an other defect" ...
Waiting this moment, i will continue to "Listen" and try to improve things in the dark, with a VERY poor correlation between what I hear and what I measure. Adding that most of our measurements are made with continuous sinusoidal or square signals, very far from the constant dynamic and harmonic changes of musical signals, we are not measuring in the same conditions than we listen.
 
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And your Cop friend is possibly scared to come on line because of me.

Huh?

Cop?

Where do you get this stuff from?

You guys are killing off diyAudio - something has happened in recent times that is really awful and you don't mind being a part of that?

Some of us want the old diyAudio back. Where we could have an open discussion and just have some fun. You guys have taken out the fun and I don't exactly know what to call it what you have replaced it with. But it leaves a bad taste in the mouth.

I joined in January 2003 - it sure is not like it used to be.

I have an idea - you guys keep to the Blowtorch II thread and keep hurling insults at each - and let the rest of us have DIY back, the way it used to be before the self-appointed thought police killed the joy.

We need to stop this rot.


 
Stuart, I have given so much away, your repeated defamatory remarks are hurtful and totally unfair. The discussion we could have had, had nothing to do with what I do for a living. I have helped untold people with their struggles with DIY, being a constant encouragement to them and not to give up. To suggest that this is for greed makes me justifiably angry - because it is not true. Also, we all have a change of mind, somebody pushes you in one direction because they may be well-meaning, but one can always change their mind. Will you allow for the fact that I did that, and that I believe in my heart that I did it for the greater good? If a person stumbles, do you push them down while they are down, or do you extend your hand to help them up? I changed my mind and ask you to respect that. I am not motivated by greed - money actually does not mean that much to me. A good life and good friends, spreading cheer and because the Good Lord said "There is more happiness in giving than receiving."

Do we now have an understanding - and can we now have a civil discourse without you resorting to defame me again?

I don't keep grudges - and I won't, as long as those hurtful and wrong imputing of my motives stop.

I thank you in advance.


 
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