Russian PIO cap source?

[Retrovert]

There are lots of threads on many forums supporting this and there are many people in the business using these caps.. You claim nobody has done any testing, as you say it is incumbent on you, the party asserting that magical claim, to prove it.

No, that's requiring that I prove a negative. I'm not the one making a claims about reliability, stability, or performance .

The OP asked about reliability. I addressed the issue of changes in characteristics from chemical changes.

This is pointless and going around in circles. Not wasting my time.

When you have some data that comes from actual measurements using scientific instruments, let me know.

 

[Selmerdave]

When you have some data that comes from actual measurements using scientific instruments, let me know.

And you kindly do the same, it's worth noting that you have not provided one bit of data or evidence about the caps in question, nor have you provided one example of any of the things you describe actually happening in one of these caps.

 

[crispycircuit]

The point is many people love them and some don't..... What about Russian resistors?

 

[sKiZo]

Those are the ones that don't like them ...

Must ... resist!

 

[BillWojo]

Yea, I'm getting ready to put an order in for some 0.1mF Russian PIO caps to try as bypass caps in a crossover build. Not sure on the type though. K42Y-2 or K40Y-9. Than there is the teflon FT-3 as well but there kinda pricey. Does anybody know the difference between the two types?
I am in full agreement with Selmerdave on his last post. I have yet to hear anything negative about any of these caps. All positive reports so far. I'm sure that some of the folks over at the DIYaudio forum or the EEVBlog have run exhaustive test on these. If there were problems it would have been put on blast by now. Bad news travels fast.

BillWojo

 

[Sam Cogley]

This is about the best list of the old Soviet cap types that I've ever found: http://tubes-store.com/article_info.php?articles_id=4

Honestly, from looking at the shape of the body, the only apparent difference between the K40Y and the K42Y is that the K42Y has a green insulating coating.

 

[Retrovert]

Honestly, from looking at the shape of the body, the only apparent difference between the K40Y and the K42Y is that the K42Y has a green insulating coating.

Not quite. Different internal construction.

I looked up my notes from some years ago when I researched the differences:

Designation Insulator and Construction
K40 Dual PIO Layers w/ Middle Foil Layer; Total = 3 Layers (Bumblebee equiv.), Use = AC Signal
K42 Dual PIO Layers: One Layer Impregnated w/ Oil, One Metallized Layer; Total = 2 Layers, Use = DC Power or Pulsed DC​

The K40 is your Bumblebee replacement.
The K42 is metalized dual-layer, similar to metalized film.

The recommended usage was from the datasheets (in Cyrillic) which was translated for me as I don't read Russian.

BTW: the K4x series capacitors are thirty to forty years old, dating to the 1980s.

Disclaimer: no warranty on data, it was assembled from vendors in Russia, Ukraine, Poland, etc. at least five years ago.

 

[Lavane]

Also place of manufacture can make a difference. Other non audio related items ive bought and continue to buy come from cold war russia. And ive found difderences in quality depending on what plant it comes out of. With the PIO caps ive wondered about quality control between factories.

 

[Sam Cogley]

As many of these things are in use, if there were vast problems, I think we'd be hearing about it.

 

[prelius]

Retrovert,

There are plenty of well-documented tests and analysis of Russian-made caps for use in HiFi audio. Many of them published on the Internet. Russian audio enthusiasts, just like their American "brothers" been discussing the topic of "best" cap ad-nauseum for many,many years... Of course, 100% of these discussions are in Russian. One of the most complete and most often referenced one is in a link below:

http://www.electroclub.info/other/conders1.htm. Try Google translator.

General consensus among Russian audiophiles is that Western-made caps (and in many cases, Chinese-made), have superior sonic characteristics compared to their Russian-made equivalents. People prefer BlackGate, Solen, Wima, VitaminQ, to their corresponding Russian equivalents. But all Russian caps that made through military QA tests, match or exceed their published specs. And those specs are just as tough as any US military specs. In the USSR, there was an organization called Metrology Labs. Basically these were technical/scientific labs that provided independent control of QA (GosPriemka) departments of all plants/factories. They tested everything (non-classified) that was made for the military: from pure alcohol, ball bearings and diamond cutters to vacuum tubes and capacitors/resistors. The samples used in tests would have already passed through GosPriemka ( meaning they already met or succeeded all the specs). The allowance for bad parts discovered after GosPriemka was the sampling error rate of the whole shipment, not a fraction more. And if that allowance was exceeded, the heads at the plants/factories rolled: people got stripped of their ranks and awards, demoted or lost jobs (these were "light" punishments), or went to jail. What I am trying to say is that if you bought Russian mil specs parts, they will meet or exceed their published specs. Otherwise, you got cheated. Now, how the tech specs of the caps translate into audio quality, it a totally different discussion (the one I am not going to even touch).

K40-Y9 mil specs used solid paper and mineral oil, never pulp and castor oil. If you ever saw those materials in K40-Y9, these caps were either counterfeit, or made in the early 90's when QA, along with the rest of the USSR crumbled. Now these caps are made is a totally different conversation (and an interesting one), but that is why I don't buy parts made in Russia between 1989 through 2002. Also, according to the specs, K40-Y9 have 10,000 hours of guaranteed work-time, and 15 years storage, which is very conservative, given their internal construction.

Cheers, Paul.

 

[BillWojo]

Paul, how do you read the date codes on these caps?
Thanks

BillWojo

 

[Sam Cogley]

That's a good question. I have some that appear to have a recognizable month/year date code, and others with four digit numbers that don't make sense as any sort of date.

 

[primosounds]

A valid concern ...

Had some fun with mine. Pretty much standard to heat shrink the leads in tight areas, but I went an extra step and insulated the entire cap.

The white sleeves are standard heat shrink insulators used for underground romex, available at the local hardware. I printed up the labels on Avery sheet stock and trimmed them to fit. What can I say ... slow day, eh. <G>

Very nice, My white heat shrink always gets smudged with finger prints and such. Also i need to get a labelmaker. Did you use a computer program with your printer?

 

[sKiZo]

Made the labels with photoshop and my cheapo HP laser printer, and just ran a couple samples first on regular paper to check the size ... adjusted as needed.

As I said ... slow day, eh. <G>

My only concern was if it'd stick well to the heat shrink, so I left long tails on the labels so there's plenty of overlap. Couple years after, they're doing fine.

That's a good question. I have some that appear to have a recognizable month/year date code, and others with four digit numbers that don't make sense as any sort of date.

Not to forget, Cyrillic lettering has a lot of characters that look the same as some Latin, but get lost in translation ...

https://en.wikipedia.org/wiki/Russian_tube_designations

... and I never could get a handle on Euro dates either ...

Oh. I DO know the date is Polish if she braids the hair on her arms ... (ba dump dump)

 

[primosounds]

Ah blast! using the computer and a laser printer, that would be another skill set i need to acquire. I was hoping it was one of those label makers that is hand held and would accept a thumb drive or plugged into a computer. Cheers.

 

[prelius]

There are two standards for labeling manufacturing dates on the caps:

1. 4-digit notation: first two show the year; second pair shows the absolute week of that year when the cap was made. For example, "8852" means the cap was made during the last week of December 1988.
2. Letter/Digit: first is a letter of Latin alphabet.

I am attaching the the pic of the second standard below..Last column on the right shows the coded for the month...

Cheers, Paul

 

[Sam Cogley]

There are two standards for labeling manufacturing dates on the caps:

1. 4-digit notation: first two show the year; second pair shows the absolute week of that year when the cap was made. For example, "8852" means the cap was made during the last week of December 1988.
2. Letter/Digit: first is a letter of Latin alphabet.

I am attaching the the pic of the second standard below..Last column on the right shows the coded for the month...

Cheers, Paul

Looking at some I have here, they don't adhere to either standard.
K40Y-9, date code 1081
K42Y-2, date code 9009
K40Y-9, date code 9007
K42Y-2, date code 08 83
K42Y-2, date code 9001

 

[sKiZo]

Dug this up. Russian Marakov (military) date codes ...

Д - 1953
Е - 1954
Ж - 1955
З - 1956
И - 1957
К - 1958
Л - 1959
М 1960
P 1961

 

[Selmerdave]

Just a follow-up to this thread. I had my ESR meter out so I decided to test a bunch of caps. Here's what I got at 1k:

New:
Sprague 716P 0.47/400 - 0.14 ohm
Multicap 0.022/600 - 1.8 ohm
Russian K40-Y9 0.1/630 - 7.7 ohm
Russian K40-Y9 0.022/400 - 60.7 ohm
Russian K40-Y9B (red) 0.047/400 - 14.5 ohm
TC (yellow) .047/630 - 13.7 ohm
CDE 0.047/600 - 1.7 ohm
CDE Silver Mica 560pF/500 - 180 ohm
Vishay DC Link 10uF/500 - 0.06 ohm
Panasonic DC Link 40uF/500 - 0.05 ohm

Used:
Auricap 0.1/600 - 0.54 ohm
Auricap 0.047/600 - 0.94 ohm
Tracon 0.1/400 - 6.6 ohm
Ceracap 0.047/400 - 13.1 ohm
Bumblebee 0.1/? - 46.5 ohm
Pyramid IMP 0.1/400 - 11.9 ohm
4PS P10 (orange drop type) 0.1/400 - 22 ohm
225P 0.047/600 - 12 ohm
Aerovox Duranite (blue) - .047/600 - 28.4 ohm
Sprague Atom (elec) - 10uF/500 - 4 ohm
CE can elec 20uF/525 - 2.9 ohm
HH Scott elec 20uF/450 - 2.9 ohm
Cornell-Dublier Oil cap - 6uF/600 - 0.34 ohm
Unknown oil cap - 4uF/230VAC - 0.99 ohm
Solen MKP 4.7uF/400 - 0.06 ohm
Angela MKP 1uF/630 - 0.09 ohm

That's much of what I had handy, in a number of cases I had multiples of the caps and checked to see if/that they measured similarly, they all did..

Dave

 

[Billy Oxygen]

Analysis:
-----------------------------------------------------------------------------------------------------------
New 1.5 uF Cornell Dublier
(touts low ESR for this specific model) Results: 1.44 uF .25 ohms ESR

NOS 1.5 uF Russian PIO Results 1.51 uF .30 ohms ESR
(military)
---------------------------------------------------------------------------------------------------------
New 1.0 uF Cornell Dublier
(touts low ESR for this specific model) Results: .96 uF .38 ohms ESR

NOS 1.0 uF Russian PIO Results .98 uF .45 ohms ESR
(military)
--------------------------------------------------------------------------------------------------------------

Opinion:


I use the NOS Russian PIO in blends with new film caps to replace electrolytics. in vintage speakers, and also the .01 to bypass original film caps in vintage mid and tweeter circuits whether they had bypass to begin with or not.

Once I integrated the Russian PIO's into the D-9 crossovers my work was done. My D-9's are more dynamic than any other speaker in their class that I have listened to, are not bright, and are never fatiguing hour after hour. I could not have said the same before the recap.