John Curl's Blowtorch preamplifier part III

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Did I say it doesn't irritate me? But your quoted characters have at least a sense of humor, far from the grumpy biased attitude accompanying the posts I quoted (yours too, BTW). This is one good reason why they don't stand as a thorn in my eye. Another one is they don't appear to have any axe to grind, or hold any grudges.

Otherwise, the "you too" argument is childish, and I suspect you know it.
Please also be aware that Mark is being ignorant and is just plain wrong in his accusations
 
How very ignorant and presumptuous of you.

Sorry. I didn't mean to say it was a true fact. I was trying to point out that Syn08 described application of biased judgement. I do not think you do not contribute adequately myself, but I also think the same for Jakob and Merrill, and for ToS too. I know you all have your own individual points of view, yet you all are welcome and worthy from my perspective, same as everyone else here.

Maybe some of the following would help explain more about human nature:
Psychology of Media Bias (...or the perception of it)
Cognitive Biases and the Human Brain - The Atlantic

It is easy to see bias in others, and almost impossible to see it in ourselves. Very difficult to overcome, if not impossible. I have been working on it for a long time with only limited success, although I do seem to get better at triggering recognition of my own biases at times. I am happy when I can notice it, but often doesn't work.
 
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It is easy to see bias in others, and almost impossible to see it in ourselves. Very difficult to overcome, if not impossible.

**** me, physics, math, EE, etc... don't have any bias. Keep your comment for those claiming the Wavac amplifier sounds better/worse than the Dartzeel amplifier.

The bias considering all those making statements supported by STEM biased puts you directly in the biased clowns category. You are in a good company there.
 
url=https://audiocounsel.co.uk/brands/naim/malcolm-stewart-interviews-julian-vereker/]Malcolm Stewart interviews Julian Vereker - Audio Counsel[/url]
George

In my first job out of college I ran a repair department for a small chain of seven high-end stores. We sold Linn/Naim, and I was invited to meet with a Naim rep who claimed to have been trained by Julian. I looked forward to it and had suggestions and some critiques for the Naim gear which was not terribly reliable...He blew me off and instead did a sales pitch for their directional cables, but couldn't tell me which way they were supposed to go nor could he hear it when they were reversed. In a typical manner he blamed that on the equipment and the room (an excellent Linn/Naim 1 speaker pair only room per IT's recommendations), and the jet lag...etc...

IME there was much better gear than Naim for the price. Regarding Linn, the real advantage of that TT, and compared to many decks it is a very large advantage, is isolation from external stimulus. S/N analysis with the needle on a stationary disk showed it's superiority. Also their stout linking of the armboard to the platter bearing is laudable at quelling chassis resonances. However their sales pitch for belt drive's superiority over Direct Drive (which has to be constantly wrong ya know, if you knew electronics, you would know that a servo needs error to work) was itself so wrong and easy to disprove. I showed them a Sound Technology sweep of a Linn playing the CBS test record's 3 KHz track, and it's P-P wow and flutter as well were several times worse than the Technics 1200, which itself is not the best DD table in that respect especially compared to a few Luxman DDs, which were the lowest I ever tested. His answer was the record's hole was punched out of center, but he was undeterrred by the fact that the same record had lower wow and flutter on the Technics.

This being said, I really liked the LP12 because it's sonic background is quite black compared to many decks, and it showed me the sonic importance of isolation from external vibration. Of course as history has shown, in an effort to correct the speed accuracy flaw they offered a string of "motor and belt upgrades" which I installed in many TTs which (for the Linn price point) should have been called bug fixes.

I am always open to new ideas, indeed learning is what gives life interest but new ideas have to pass simple BS tests before investing time/money in more in-depth analysis. If the person claiming the advance cannot explain how it works, and cannot detect if it is even working or not I believe skepticism is appropriate. This is not about being an objectivist, listening is the final verification, however you must test and listen. Just listening is not enough; many euphonic equipment errors can lead people astray...or lead to the development of distorting processors like the Aural Exciter, et.al...

Howie
 
I am always open to new ideas, indeed learning is what gives life interest but new ideas have to pass simple BS tests before investing time/money in more in-depth analysis. If the person claiming the advance cannot explain how it works, and cannot detect if it is even working or not I believe skepticism is appropriate. This is not about being an objectivist, listening is the final verification, however you must test and listen. Just listening is not enough; many euphonic equipment errors can lead people astray...or lead to the development of distorting processors like the Aural Exciter, et.al...

Howie

I’ve got a aphex 204 in my mastering chain, a little goes a long way; especially the ‘big bottom’......I only use that on recordings that need some help with the bass (works good on stand up bass)
 
I’ve got a aphex 204 in my mastering chain, a little goes a long way; especially the ‘big bottom’......I only use that on recordings that need some help with the bass (works good on stand up bass)

Yup, I hear you, been there, initially overused it! The Aural Exciter can do some great things to fatten up a mix, as can the BBE Sonic Maximizer, they can both improve the sound of the right kind of music...of course in this use we are talking about producing music, not reproducing it, where euphonic distortions should not be considered appropriate.

Best regards,
Howie
 
Yup, I hear you, been there, initially overused it! The Aural Exciter can do some great things to fatten up a mix, as can the BBE Sonic Maximizer, they can both improve the sound of the right kind of music...of course in this use we are talking about producing music, not reproducing it, where euphonic distortions should not be considered appropriate.

Best regards,
Howie

I used it in mastering my own recordings with decent success......but like you said when I tried playing around with ccm it did nothing but damage!
 
If you knew anything about audio advancement this might work. Go play with your mud or whatever you drone on about and leave real audio advancement to people who dont imagine a copper heat sink sounds different.

Actually I did some measurements of copper vs aluminum heat spreaders. I was looking at the base to emitter junction voltage drop switching between 5 mA and 200 mA collector current. Not surprisingly the junction voltage dropped after it switched from 200 mA to 5 mA going down a bit and then recovered quite quickly. It was different for copper than aluminum.

If I get a chance to do the test again I will use an oscilloscope that allows me to download the images. I will need to use a low noise preamp with the one I have that is easiest to use that way. The voltage across the junction is of course not linear and to make things tougher the higher current across the internal effective emitter resistance results in a much larger voltage change than does the thermal recovery voltage change.

But there is a measurable difference between mechanically identical heat spreaders on junction temperature recovery time.

So Max may be crazy, but perhaps not on that issue. Eccentric is perhaps the better label.
 
Hi Dan,
Just to make a point, the entire field of audio was invented and advanced by telephone engineers. Even the active components we use were improved by telephone engineers. That includes tubes, and the transistor was invented by telephone engineers.

Just keeping the record straight ...

-Chris
 
Actually I did some measurements of copper vs aluminum heat spreaders. I was looking at the base to emitter junction voltage drop switching between 5 mA and 200 mA collector current. Not surprisingly the junction voltage dropped after it switched from 200 mA to 5 mA going down a bit and then recovered quite quickly. It was different for copper than aluminum.

If I get a chance to do the test again I will use an oscilloscope that allows me to download the images. I will need to use a low noise preamp with the one I have that is easiest to use that way. The voltage across the junction is of course not linear and to make things tougher the higher current across the internal effective emitter resistance results in a much larger voltage change than does the thermal recovery voltage change.

But there is a measurable difference between mechanically identical heat spreaders on junction temperature recovery time.

So Max may be crazy, but perhaps not on that issue. Eccentric is perhaps the better label.

The superiority of copper thermal conductivity over aluminum is well established. Current high-power solid state RF amplifiers all use copper heat spreaders to couple to the aluminum heatsinks (I own one such amp...). Many solder the $$$ LDMOS transistors directly to the copper heat spreader for even better thermal transfer:
https://www.w6pql.com/video/ldmos2copper.wmv

Is that what Dan was referring to?

Howie
 
The superiority of copper thermal conductivity over aluminum is well established. Current high-power solid state RF amplifiers all use copper heat spreaders to couple to the aluminum heatsinks (I own one such amp...). Many solder the $$$ LDMOS transistors directly to the copper heat spreader for even better thermal transfer:
https://www.w6pql.com/video/ldmos2copper.wmv

Is that what Dan was referring to?

Howie

There is another thread where someone mentioned his amplifier sounded better when he changed from aluminum to copper heatspreaders. Of course everyone dumped on him. So out of curiosity I tried a simple measurement to see if a difference in instantaneous die temperature changes was measurable. Turns out it was.

Folks don't seem to understand heatsink related thermal resistance to ambient is different than thermal conductivity, mass and time constant. But unawares never seems to stop offering opinions in my opinion!
 
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There is another thread where someone mentioned his amplifier sounded better when he changed from aluminum to copper heatspreaders. Of course everyone dumped on him. So out of curiosity I tried a simple measurement to see if a difference in instantaneous die temperature changes was measurable. Turns out it was.

Folks don't seem to understand heatsink related thermal resistance to ambient is different than thermal conductivity, mass and time constant. But unawares never seems to stop offering opinions in my opinion!

I feel your pain, I manufacture and sell heatsinks, and despite authoring short tutorials and countless posts in forums on the subject I fight that battle often.

Cheers!
Howie
 
I feel your pain, I manufacture and sell heatsinks, and despite authoring short tutorials and countless posts in forums on the subject I fight that battle often.

Cheers!
Howie

Have you seen or used the liquid metal thermal compounds? I believe they are Galinstan or similar. Popular with the PC crowd now that the power density of CPUs and GPUs are so high that the interface between the die and heat spreader is becoming a bigger issue. I got a 10-15C decrease in load temps by replacing the standard Intel thermal paste with it. Problem is it doesn't play well with aluminum and it's conductive. Most of the high end heatsink bases along with the CPU heatspreaders are nickel plated copper.
 
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