Pio russian capacitor K42-11...is good ?

The different suffix,11, may mean it is a variant for special purpose,for instance,high frequency use. I am sure some member of the forum will know this.

Actually, I have just looked at the ones you mean(which I have not tried) and they seem to be large value lower voltage without the usual glass sealed steel case.

I did not see post number 2- yes,probably no oil!
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K42Y-2 is a PIO capacitor ?


Some time ago I got a lot of K42Y-2 tubes in ebay.
I make a comparation with a old ( 60´s) brazilian made PIO capacitor( the brand make this oil capacitor until today here) and the brazilian sound best...this K42Y-2 is really PIO or for the russians sellers PIO is Plastic In Oil ?
In ebay have a confusion and few information about the material used in this russian capacitors...

Here is some info from Russian book:

Low voltage, low frequency caps:
Paper: КБГ (КБГ-И, КБГ-МН, КБГ-МП), ОКБГ (ОКБГ-И, ОКБГ-МН, ОКБГ-МП. ОКБГ-М), БГТ, К40П-2, К40У-5, К40У-9, К40-11, БМ-2, БМТ-2
Metallized paper: МБГ (МБГП, МБГЦ), МБГИ, МБГН, МБГО, МБГТ, МБГЧ (МБГЧ-1, МБГЧ-2), МБМ, КМБП, К42У-2, К42П-5, К42Ч-6, К42-4, К42-8, К42-11, К42-18, К42-19
That's all I can find
Very useful information. :D

I'm actually surprised at how well google translate worked on this page - it's completely readable.. :D

Except 76, it is lacquer-film.

Google translate gets better and better, thanks to many contributors. I myself contribute almost every time I see incorrect translation. I wish my English would improve so fast. ;)


Paid Member
2009-08-20 3:16 pm
KC Metro
Wavebourn, no need to apologize for your English; your written skills are much better than the verbal skills of many native American English speakers I know. :)

I recently completed a VTA ST-70 build, and I went with the Russian PIO cap upgrade. I can't say they made a difference as I didn't hear the amp before installing them. I can say the amp sounds very nice. I was struck by their physical size though. They're relatively huge!
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M Gregg

Disabled Account
2010-06-28 11:04 pm
I have used either K75-10 or K75-24 in every amp I have built but always as either bypass caps for the power supply electrolytics or in the snubbing network in choke input PSU. I think it would be hard to find better caps for this purpose.
I guess they might also be suitable for parafeed caps.

Ervinl; K40U-9 and K42U-2 are available up to 1600V. Excellent eflog seller Dmitriy Kolevatov (user name uralspirit) has good selection at higher voltage and is happy to sell small numbers.