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Old 2nd August 2004, 07:38 PM   #21
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What's all this electron and magnet stuff, anyway?? Why would an electron care??
I have lots of luck with refrigerator magnets...they stick rather well..unfortunately, it does tend to attract those excess charges...perhaps using a van de graf generator in reverse will help...

(note: I don't know if south of the equator changes the van de graf polarity, maybe you have to put it upside down.?

John
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Old 2nd August 2004, 07:49 PM   #22
pburke is offline pburke  Germany
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If in doubt, read this:

http://www.audioasylum.com/forums/tu...ges/57559.html

and this

http://www.audioasylum.com/forums/bo...ges/83595.html


Here's what I did (and many others followed, confirmed results)

Turn off the tube amp and remove tubes

take a demagnetizer (I use an old Nakamichi tape head demagnetizer) and treat the tube. I spend about one minute exposing the tube from all angles to the Nak demagnetizer.

put tube back into gear

power up, warm up, listen

It works, it can be measured, and it clearly can be heard. The tubes sound better after such a treatment.

I did this to a pair of Telefunken ECC802S - the treatment seems to last quite a long time, since a second treatment about a week after my initial demagnetizing didn't seem to deliver much of a noticable improvement.

Peter
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Old 2nd August 2004, 07:50 PM   #23
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Quote:
Originally posted by jneutron
What's all this electron and magnet stuff, anyway?? Why would an electron care??
Because an electron is a charged particle. But as I said, it won't do anything good for a tube.

Tim
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Old 2nd August 2004, 08:07 PM   #24
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Quote:
Originally posted by Sch3mat1c


Because an electron is a charged particle. But as I said, it won't do anything good for a tube.

Tim
Are you sure it's a charged particle? or, just a probability?

What specifically, is the Curie temp for the materials of typical tubes? Once exceeded, is there any residual left? Curious minds want to know...

The first link provided by pburk shows an interesting difference..but, I wonder...did the person re-magnetize the tube to cause more distortion? Is the result repeatable, or did he simply do it once? Was it just contact resistance?

Is the residual magnetism of a tube structure sufficient to actually spiral the electrons? Magnetrons usually have some decent fields...small in the scheme of things, always less than 1.5 to 2 Tesla, but certainly much larger than tube residuals...I don't think the voltage gradient in regular tubes is that much lower than a mag..

Repeatability of those harmonic graphs would be nice..

Cheers, John
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Old 2nd August 2004, 08:37 PM   #25
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Repeatability of those harmonic graphs would be nice..
Yes, indeed. Contacts and time of warmup were the first two things that came to my mind when I saw those graphs. Doing this in a controlled way is a PITA, but necessary if you want to demonstrate the phenomenon (if such actually exists).

I'd also be interested to use a magnetometer on a tube before and after "treatment" and see if there is a change in magnetism, and if so, in which direction- the methods described here might actually increase remnant magnetism.
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Old 2nd August 2004, 08:54 PM   #26
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Quote:
Originally posted by SY


Yes, indeed. Contacts and time of warmup were the first two things that came to my mind when I saw those graphs. Doing this in a controlled way is a PITA, but necessary if you want to demonstrate the phenomenon (if such actually exists).

I'd also be interested to use a magnetometer on a tube before and after "treatment" and see if there is a change in magnetism, and if so, in which direction- the methods described here might actually increase remnant magnetism.
Geeze, I forgot about warmup....

It'd also be interesting to see the magnetometer while the tube is actually operating...I make the assumption the elements are too hot to retain magnetism...

Cheers, John
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Old 2nd August 2004, 09:03 PM   #27
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I make the assumption the elements are too hot to retain magnetism...
This may not be the case. Certainly things like lead outs and the support structures don't get hot enough to exceed their Curie temperature.
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Old 2nd August 2004, 09:06 PM   #28
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Originally posted by SY


This may not be the case. Certainly things like lead outs and the support structures don't get hot enough to exceed their Curie temperature.
Agreed..but if they are cool enough to be below curie, aren't they also far enough from the e stream that they don't make a diff?

Ah yes, I remember my 6L6/12AX7 days.....almost as if it was 35 years ago...

Cheers, John
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Old 2nd August 2004, 09:12 PM   #29
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Agreed..but if they are cool enough to be below curie, aren't they also far enough from the e stream that they don't make a diff?
This is a tweak. No logic or physics allowed. You've been warned!

Anyway, I don't think the plate or grid get hot enough, either. Not that they're normally magnetic material in the first place...
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Old 2nd August 2004, 09:22 PM   #30
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Originally posted by SY


This is a tweak. No logic or physics allowed. You've been warned!
OH NO!! I seem to always be getting doze warnings....

I knew that e/m physics background would lead me to a life of crime against tweak-manity..

Quote:


Anyway, I don't think the plate or grid get hot enough, either. Not that they're normally magnetic material in the first place...
hmmm..you've never seem my tube contraptions, have you....if it ain't cherry red, it just....aint..

OH, btw, Sy?? twas a dark day when you removed that chick pic from your profile....I really liked her...da guy...he's not my type...

Cheers, John
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