K31-11 Russian silver mica

fred76 · 30th June 2007, 10:33 AM

Hello,

Any of you guys tried these surplus Russian silver mica (K31-11)?

Here's my experience with micas... I used some CDE micas in RIAA, two different phono designs both tube. The first design is with 12AX7's with no name polys and replaced them with CDE's, resolution went up notches and music sound more natural/relaxed but still relatively neutral. The other design uses high gm tubes and sounded too upfront with a bit of edge in the sound when I tried to replace some polyprops with CDE's (magnetic)... Some say it's the magnetic materials that makes them bright, but I've heard the pricey ACL micas that are magnetic but they don't sound metallic.

FWIW, the seller claims that the Rusian micas pic'd above are not magnetic.

Thanks.

AndrewT · 2nd July 2007, 08:59 AM

Hi,
neither mica nor silver are magnetic.
Are the leads silver or copper or tinned steel?

Tolerance may be a bigger issue.

fred76 · 2nd July 2007, 08:08 PM

Hi Andrew,

The seller says the leads aren't magnetic, I still don't know about the tolerance though... The CDE's I used before have magnetic leads. Now thinking back, the phono design that sounded 'upfront' in character have low V across the RIAA caps (I since put back the poly types.) That 'might' be a factor of them sounding different than the ones used in the other phono design which has >100VDC across the caps.

I'm also looking at these ones which he sells, unique that they are oil-filled micas:

They look like to have steel leads. He hasn't replied to me yet about these. Tolerance is tight at 0.3%.

It seems that nobody yet here posted their experiences wrt these caps except the SSG ones (modified leads).

Thanks.

fred

alboran · 21st December 2007, 09:44 PM

hi
I am very interested to capacitors in mica silver .
I want to change the capacitors of the riia in my phono.
do I want to use mica silver, where can I buy capacitors of very good quality?
give me your suggestion on capacitors in mica silver.
graces and regards

Conrad Hoffman · 22nd December 2007, 12:34 AM

I've no idea what sonic changes are incurred by various cap types in the RIAA stage, as it's too tough to set up a reasonable test. I prefer polystyrene if at all possible, based on it's excellent performance in all areas. It may be bettered by Teflon, but the necessary values are invariably hard to get or absurdly expensive. My next choice is polypropylene, which is nearly as good as polystyrene. That's what's in my RIAA stage right now. I've used silver mica in the past, and it sounded ok, but you should be aware of a peculiarity of silver mica. It can have a very low dissipation factor, and you'd expect it to be excellent in every other way. Oddly, and in spite of the low DF, it can have a rather large dielectric absorption, far worse than the film caps. FWIW, an NPO/C0G ceramic will typically be better than all of them in every technical regard, but most people aren't aware of just how good they really are. This is just FYI, and I make no claim for the sound of any of 'em.

alboran · 22nd December 2007, 10:20 PM

hi conrad
you could give some most precise information.
which capacitors do I have to insert in the net riaa..?
you can say what type and what brand.
graces and regards

Conrad Hoffman · 23rd December 2007, 05:46 AM

Alboran- I can't tell you what to use, only general comments on the measurement of various types. You have to decide what's important, based on both specifications/measurements, and the comments of people who claim to consistently hear a difference. Though I think I have preferences, I've never been able to set up a listening test where I could say anything with confidence. Purely from measurements, my first choice would be any of the small polystyrene caps that are getting harder to find. My second choice would be polypropylene, and I buy the inexpensive ones from Digikey (Panasonic brand?). I "upgraded" my RIAA section recently from CDE silver micas, to the Panasonic polypropylenes, but whatever difference it made was very minor to my ears.

rdf · 24th December 2007, 07:55 AM

Quote:

Originally posted by Conrad Hoffman
FWIW, an NPO/C0G ceramic will typically be better than all of them in every technical regard, but most people aren't aware of just how good they really are.

Hi Conrad. I though all cermaics were very high in DA, worse than even mica. Re: the Soviet military SSGs, serengetiplains measured samples and found the DF comparable to teflon. They're my favourite coupling caps in biased locations where values permit.

alboran · 24th December 2007, 08:14 AM

hello Richard
me where I can find capacitor Soviet military SSGs?

rdf · 24th December 2007, 03:44 PM

All mine came from Ebay. Do a search for 'ssg mica'.

30th June 2007, 10:33 AM	#1
fred76 diyAudio Member Join Date: Jan 2005 Location: Manila	K31-11 Russian silver mica Hello, Any of you guys tried these surplus Russian silver mica (K31-11)? Here's my experience with micas... I used some CDE micas in RIAA, two different phono designs both tube. The first design is with 12AX7's with no name polys and replaced them with CDE's, resolution went up notches and music sound more natural/relaxed but still relatively neutral. The other design uses high gm tubes and sounded too upfront with a bit of edge in the sound when I tried to replace some polyprops with CDE's (magnetic)... Some say it's the magnetic materials that makes them bright, but I've heard the pricey ACL micas that are magnetic but they don't sound metallic. FWIW, the seller claims that the Rusian micas pic'd above are not magnetic. Thanks.

2nd July 2007, 08:59 AM	#2
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	Hi, neither mica nor silver are magnetic. Are the leads silver or copper or tinned steel? Tolerance may be a bigger issue. __________________ regards Andrew T.

24th December 2007, 03:44 PM	#10
rdf diyAudio Member Join Date: Jun 2004 Location: the thermionic past	All mine came from Ebay. Do a search for 'ssg mica'. __________________ "My loony bun is fine Benny Lava!"

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2nd July 2007, 08:08 PM	#3
fred76 diyAudio Member Join Date: Jan 2005 Location: Manila	Hi Andrew, The seller says the leads aren't magnetic, I still don't know about the tolerance though... The CDE's I used before have magnetic leads. Now thinking back, the phono design that sounded 'upfront' in character have low V across the RIAA caps (I since put back the poly types.) That 'might' be a factor of them sounding different than the ones used in the other phono design which has >100VDC across the caps. I'm also looking at these ones which he sells, unique that they are oil-filled micas: They look like to have steel leads. He hasn't replied to me yet about these. Tolerance is tight at 0.3%. It seems that nobody yet here posted their experiences wrt these caps except the SSG ones (modified leads). Thanks. fred

21st December 2007, 09:44 PM	#4
alboran diyAudio Member Join Date: Jul 2007	hi I am very interested to capacitors in mica silver . I want to change the capacitors of the riia in my phono. do I want to use mica silver, where can I buy capacitors of very good quality? give me your suggestion on capacitors in mica silver. graces and regards

22nd December 2007, 12:34 AM	#5
Conrad Hoffman diyAudio Member Join Date: Mar 2007 Location: Canandaigua, NY USA	I've no idea what sonic changes are incurred by various cap types in the RIAA stage, as it's too tough to set up a reasonable test. I prefer polystyrene if at all possible, based on it's excellent performance in all areas. It may be bettered by Teflon, but the necessary values are invariably hard to get or absurdly expensive. My next choice is polypropylene, which is nearly as good as polystyrene. That's what's in my RIAA stage right now. I've used silver mica in the past, and it sounded ok, but you should be aware of a peculiarity of silver mica. It can have a very low dissipation factor, and you'd expect it to be excellent in every other way. Oddly, and in spite of the low DF, it can have a rather large dielectric absorption, far worse than the film caps. FWIW, an NPO/C0G ceramic will typically be better than all of them in every technical regard, but most people aren't aware of just how good they really are. This is just FYI, and I make no claim for the sound of any of 'em.

22nd December 2007, 10:20 PM	#6
alboran diyAudio Member Join Date: Jul 2007	hi conrad you could give some most precise information. which capacitors do I have to insert in the net riaa..? you can say what type and what brand. graces and regards

23rd December 2007, 05:46 AM	#7
Conrad Hoffman diyAudio Member Join Date: Mar 2007 Location: Canandaigua, NY USA	Alboran- I can't tell you what to use, only general comments on the measurement of various types. You have to decide what's important, based on both specifications/measurements, and the comments of people who claim to consistently hear a difference. Though I think I have preferences, I've never been able to set up a listening test where I could say anything with confidence. Purely from measurements, my first choice would be any of the small polystyrene caps that are getting harder to find. My second choice would be polypropylene, and I buy the inexpensive ones from Digikey (Panasonic brand?). I "upgraded" my RIAA section recently from CDE silver micas, to the Panasonic polypropylenes, but whatever difference it made was very minor to my ears.

24th December 2007, 08:14 AM	#9
alboran diyAudio Member Join Date: Jul 2007	hello Richard me where I can find capacitor Soviet military SSGs?

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