John Curl's Blowtorch preamplifier part II

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Thanks KBK for tying to teach me more than I have given out here. However, do you really think this is the place to vent? I have appreciated your input and have tried to understand it. Perhaps, I am just too 'square' to get it. Yet, I have followed your progress with your cables. Fantastic stuff.
It is so difficult for me to even discuss stuff that has been heard and measured by myself and my associates, that talking above and beyond that is just not reasonable or practical on this tread. Please keep it to personal discussion between us.
 
No-one at the moment. They should. Think of a material with the dielectric properties of Teflon, but with none of the processing or mechanical issues.

Sounds interesting.

Edit: the Low thermal handling issue might rear it's head as odd harmonic distortions under heavy loading; that may include physical deformation. This is all micro levels of course, but that is our sole concern, with the other 98% being taken care of.


Got it, John.
 
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We seem to have switched from the original discussion on the capacitor generating SOUND due to magneto- and electrostriction, to a capictor generating a SIGNAL due to microphonics. A different kettle of fish.

As to the original issue, where say the cap body vibrates at less than a material molecule diameter, I wonder what the generated SPL level would be, ballpark number for a 1 in dia, 2 in length wound foil cap?

jan didden

Jan

I am crushed with work at the moment, but I did put an accelerometer on a 70 uF Solen cap and put 10 V through 100 ohms on it. The movement was measurable, certainly more than 1 atom, but I do not have time to work out the calibration for a better estimate.

I expect almost anyone can calculate the force from the emf and the yield strength of the dielectric and come up with almost no movement. But when you figure in the air gap from limited winding tension and age stretching, all bets are off.

I would do more but I have some other article to get working on :)

ES
 
I would like to see some real measurements of different brands of capacitors. Just this week, an associate of mine decided to tell me the ins and outs of making the perfect capacitor. This went on for more than 1 hour, and was based on his 65 years of real experience, started by working in WW2 on pulse counters for Fermi in Chicago.
I had to tell him that I was having enough trouble with just cap vibration and DA. This is just the beginning. Some of the physical principles pointed out by the Clarity paper were discussed, even before it was put up on this thread. This frequency doubling problem is very interesting. I hope to study it further.
 
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Jan

I am crushed with work at the moment, but I did put an accelerometer on a 70 uF Solen cap and put 10 V through 100 ohms on it. The movement was measurable, certainly more than 1 atom, but I do not have time to work out the calibration for a better estimate.

I expect almost anyone can calculate the force from the emf and the yield strength of the dielectric and come up with almost no movement. But when you figure in the air gap from limited winding tension and age stretching, all bets are off.

I would do more but I have some other article to get working on :)

ES

Ed,

The original study done by CarityCap used a laser inferometer to measure the vibration amplitude. That's how they came to 'less than a molecule'. I'll see if I can find the paper.

On point 2: roger that :cool:

Edit: here's the AES paper: http://www.linearaudio.nl/Miscellaneous/forces in capacitors.pdf .
Note that the test uses impulse discharging of the caps to increase the effect, which is not a realistic condition in most audio applications.
Vibration excursion is said to be in the '10's of pico-meters'.

jan didden
 
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@Ed: Thus my caution on winding tension and my warning against caps that are not made on high speed mass-production machinery.

Jacco, there's also Zeon and Topas. They're interested, but there's no interest among the companies that produce film for caps. Setting up a line requires that the market already be there- in commodity markets, people rarely work on spec.
 
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