Cap value more important than cap materials? An experiment.

MATTM

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Respectfully and peacefully, I'll express another POV:

-the difference appears to me as surprising precisely because caps of lower value sound darker than their higher capacitance counterparts.

-Being based on frequency analysis, the screenshots above translate faithfully what I hear: a more open tone with the higher capacitance while it should be the contrary...

This paradox is the reason why I've created this topic.

I've still many other screenshots collected during 10 years in such experiments but I wanted to compare these pictures for the reasons explained above. :)

You get an "A" for effort bro :)
 

Jason Taylor

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the difference appears to me as surprising precisely because caps of lower value sound darker than their higher capacitance counterparts.

-Being based on frequency analysis, the screenshots above translate faithfully what I hear: a more open tone with the higher capacitance while it should be the contrary...

Get some:

http://www.hificritic.com/downloads/APassiveRole.pdf

I believe this answers your questions sir.

JT
 

bill m

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Freefrog, for this test to be viable, and to avoid confusion you should use the same guitar with the same pickups and pots. You should then take your measurements with the .022 OD, then remove them and install the .033 pio and take measurements again. Then overlay the 2 plots and see what you have. At what frequency did you measure the Q and the L? My guess would be 1khz, as most LCR meters and software are only capable that frequency at max. A lot of different things happen when you get beyond that 1khz, and up to the 6khz range, but you need industrial equipment that costs thousands of dollars.

I have noticed that vintage bee's, black beauties, astrons, mustard caps, etc. do have a broader frequency range than most modern counterparts, such as modern OD's with regard to the same measured capacitance at 1khz.
 

freefrog

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Get some:

http://www.hificritic.com/downloads/APassiveRole.pdf

I believe this answers your questions sir.

JT

Thx a lot for this extremely interesting link, Jason. Not only it digs our reflection but it replaces some data that I've lost. :)


Freefrog, for this test to be viable, and to avoid confusion you should use the same guitar with the same pickups and pots. You should then take your measurements with the .022 OD, then remove them and install the .033 pio and take measurements again. Then overlay the 2 plots and see what you have. At what frequency did you measure the Q and the L? My guess would be 1khz, as most LCR meters and software are only capable that frequency at max. A lot of different things happen when you get beyond that 1khz, and up to the 6khz range, but you need industrial equipment that costs thousands of dollars.

Bill,
I've not presented the test above as "scientific": intentionally, it's a mere translation of what I've noticed sonically.
That said, if the pickups and caps were different in this case, the guitar and pots were still the same.

In the past, here or elsewhere, I've published other tests done with a specific wiring harness allowing to swap just the caps but these tests haven't inspired much comments...

To answer to your question: my measurements are done @ 400hz if memory serves me. I know and understand that the testing frequency used changes the results.

I have noticed that vintage bee's, black beauties, astrons, mustard caps, etc. do have a broader frequency range than most modern counterparts, such as modern OD's with regard to the same measured capacitance at 1khz.

Aahhh (sigh of relief): thx for this testimonial! :)
 

Gibsonclassic2001

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I notice larger tonal/responce with a electrolyt vs poly.
Largest problem with old caps is to find 2 that measure the same / close to spec.

Sprauge 5n measure 4.7n and my mustards 4.7n measure 5n.
No wonder blind test without multimeter always fail.

:)
 

mechtech

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Some caps react/interact to different resistance .
Their effective values change at extremes .
So the cap's value with the tone rolled off could vary one to another.
But that is a net cap value change, isn't it?
 

Jason Taylor

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Now, if someone has an explanation about the Q factor which becomes obviously lower with the PIO, I'm all ears.
Once again, if someone has a clear explanation to offer, I'll be grateful.:cool:

This has been on my mind.

I believe its because the PIO has lower resonance due to the dampening effect of the oil on the mechanical resonance of the capacitor.

This along with ESR and dampening are what's causing the effects you got I believe.

In other words, the polypropalene Orange Drop is more solid structure (being that it is not hollow with paper in oil in it) so it has greater mechanical resonance.

Again... look at the link I provided I believe its the answer you seek.

Here's more good reading:

Capacitor ESR, Dissipation Factor, Loss Tangent and Q :: Radio-Electronics.Com

Let me know what you folks think.

Jason
 

freefrog

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This has been on my mind.

I believe its because the PIO has lower resonance due to the dampening effect of the oil on the mechanical resonance of the capacitor.

This along with ESR and dampening are what's causing the effects you got I believe.

In other words, the polypropalene Orange Drop is more solid structure (being that it is not hollow with paper in oil in it) so it has greater mechanical resonance.

Again... look at the link I provided I believe its the answer you seek.

Here's more good reading:

Capacitor ESR, Dissipation Factor, Loss Tangent and Q :: Radio-Electronics.Com

Let me know what you folks think.

Jason

Thx for the link!:dude:

Regarding your explanation: we are on the same track. I've always noticed a kind of micro-reverb / short delay / comb filtering with PIO that I don't obtain with other caps. It appears to have something to do with a "slowered" mechanical resonance... :hmm:
 

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