PIO caps?

Whats the word on the Russian PIO caps I see around?
If I wanted really good PIO should I go with something like Jensen or will the Russian PIO
be nice and smooth...

Cheers!

good one. I've been looking to try these out in place of orange drops , but I have not found a reasonably cheap stash yet. Ocassionally I find some Aerovox, Astron, Vitamin Q's , Goodall , Cornell Dub's etc. in old dilapidated lab equipment. I hear the new ones are also nice, but $$$.  Sometimes the paper and wax caps are worthy too, but leaky I think. Still the sound is organic and musical compared to current production " clean sounding" orange drops.

All things considered Orange drops are not bad I use them a lot. 715P,716P

Have not tried the CCCP PIO caps , I'm interested though.

I priced out Jensens for the build I'm doing at about 650usd.

I am now VERY curious about the ruskie-caps!

I have found one source possibly.
http://www.machmat.com/
Look familiar to anyone?

Hi,

i just tested PIO Cornell Dubilier cap at the output of tube mic pre. Result was pretty interesting, sound became a little more detailed and "real". But i couldn't hear any difference in bass, only in mids and highs. This was maybe due to the fact that cap i had at hand wasn't big enough for the task.
I got pretty excited by this result, i will surely use them in preamp i'm building.
I have many other poliester and polypropylene caps(metalized and foil) and can't hear any difference between them when both caps on test are of good quality. I even bought some expensive ones and they were not any better than, say, 1u/630V polypro caps for 4-5 euros.
Btw, differences i'm talking about are not very big. I could only hear them on vocals, some acoustic instruments and mixes.

Miha

The CCCPs that I've used sound pretty clean and hi-fi.  They were manufactured in the late 80's all NOS.

Be careful with used American ones.  In a given circuit, I've found some used cartridge types that sounded a bit muddy,  distorted and rolled off and other ones that sounded fine though all tested above the rated capacitance. So no way to really tell in advance.

I think the Jensen's are a bit over priced as are the Vitamin Qs thanks to the Geetar amp crowd.

I guess it comes down to what effect you want from them.  

There's a number of ebay sellers for the Russian caps with decent prices. Nebraska Surplus has NOS American types for pretty decent prices as well.

Interesting thoughts...yes I agree the Jensens are pricey.

AFA modern replacements, the stereo boys (and Jim Williams it would seem) like these: http://www.thlaudio.com/mitcpitmE.htm

@ lasso - have you compared the ruskiecaps with something hifi like the Jensens or Audionote modern PIO caps?

stitch-o said:

Interesting thoughts...yes I agree the Jensens are pricey.

AFA modern replacements, the stereo boys (and Jim Williams it would seem) like these: http://www.thlaudio.com/mitcpitmE.htm

@ lasso - have you compared the ruskiecaps with something hifi like the Jensens or Audionote modern PIO caps?

Click to expand...

Not with the Jensens - only with a number of Vit Qs I have lying around.  If anything, the Russians maybe were a little crisper/clearer. That may have been because they were less old than the NOS Qs.

On a different note, in case you're looking at use in a passive EQ - I've certainly noticed that some caps sound 'faster' than others in terms of their job of boosting or cutting the given freq. This kind of goes across the board as I was using any and every type cap I had in a boosting circuit(cap only, no LC) - generic films, orange drops, bumble bees, PIOs, etc.  It was an interesting enough and strong enough effect that I would consider it important to sort through your prospectives before commiting them to build.  The tonal qualities in this case were very subtle with no wow factor, but the degree/slowness-fastness of the boosting effect was striking.  Don't know what causes this. There was an interesting paper I came across on caps that mentioned something about 'electron trapping' that may be related to this.  If I can dig it up I'll post it here     

I've been playing with replacing run-of-the-mill modern caps (orange drops, Wimas, Solens) with pio types that I recently scored from an estate sale. I liked an Auricap replacing the Solen (honky) and Wima (clean and crisp) in a Royer LDC tube mod that is perennially bright. Softened the top end and gave it a nicer upper mid presence. Tried some JAN Vitamin Q-looking types (no brand name) in some tube pres and they again added silkiness to the high end, especially when compared to Solens. My conclusion is that I don't like Solens 

I didn't want to believe all the pio hype, but I'm hearing something nice here.

Need to finish my Pultec so I can try some in EQ filter applications...

pH said:

Need to finish my Pultec so I can try some in EQ filter applications...

Click to expand...

haha!
This is EXACTLY what I am building now.
A pair of p-t-p EQP1As.
I figure the original iron is ridiculously priced and the original inductors are non-exsistant
but PIO caps and carbon comp resisters could do something, right?

Howabout those MIT Multicaps?
Are they 'Solen'esq I wonder?

PH, what Wima did you use in the Royer? I've used FKPs as amp input caps once and they sounded excellent. Clean, kinda silky. Was going to use them throughout my (whenever it gets done) pultec. 

I've found several references here saying to use styrenes in the high filters...?

Ebay seems full of people selling multiples of russian PIO. Too bad I don't see a use for 50 of a single cap value.. Group ebuy anyone?

I found this to be VERY interesting with regard to "high-end caps":
http://www.laventure.net/tourist/caps.htm
Many surprises indeed, if accurate.

Hey Mitsos,
I just looked at the Wimas and they are MKMs. Guess I don't pay enough attention when ordering them.
Not that they sound bad, just that I did hear nice softening with the pios that I put in.

Btw, some of my pios are West Cap JAN, they look a lot like Vitamin Qs. From a large lot of caps, new and old, that I got from a Hi-Fi builder. Lots of different flavors to roll here, and I'm trying to let my ears (not eyes) be the judge.

schmidlin said:

I found this to be VERY interesting with regard to "high-end caps":
http://www.laventure.net/tourist/caps.htm
Many surprises indeed, if accurate.

Click to expand...

I almost want to replace the Solens in my D-La2a after reading that.
There are a few (semi-reputable) sources I've found that say the K40y is bang for the buck...

So I will definitely be getting some. Now I just have to find where...

Are you guys planning on using these PIOs throughout the filter sections?  I'll be curious to hear results.

mitsos said:

Are you guys planning on using these PIOs throughout the filter sections?  I'll be curious to hear results.

Click to expand...

Sure! And Amp stage. Power supply Im not so worried about.
FWIW: MIT Multicaps are pricier than Jensens. Wow.

schmidlin said:

I found this to be VERY interesting with regard to "high-end caps":
http://www.laventure.net/tourist/caps.htm
Many surprises indeed, if accurate.

Click to expand...

What a bunch of complete idiots.

1.0uF/300VDC = $269.99... A winner of their shootout.

Excuse me if I may doubt their testing procedure a bit but it seems everything ended up sorted by the prices. Most expensive came first.

Are they really that gullible?

Ref. The smart engineer here:

Kingston said:

schmidlin said:

I found this to be VERY interesting with regard to "high-end caps":
http://www.laventure.net/tourist/caps.htm
Many surprises indeed, if accurate.

Click to expand...

What a bunch of complete idiots.

1.0uF/300VDC = $269.99... A winner of their shootout.

Excuse me if I may doubt their testing procedure a bit but it seems everything ended up sorted by the prices. Most expensive came first.

Are they really that gullible?

Ref. The smart engineer here:

Click to expand...

Wonderfully cute cartoon, but somebody need to read the article.  It simply was not sorted by price.  (maybe by kickback money, but not price)  I suppose you have a better source? (shy of spending 1000's of dollars and hours?)

schmidlin said:

It simply was not sorted by price.

Click to expand...

I know I know. I was just kidding.

They were sorted by looking at the cap exterior design strapped on the front panel of the test rig.

There was also lots of chin-stroking involved.

PIO caps always intrigued me, especially the old russian ones. Never tried any at all, but am curious, and they are not expensive.. but shipping is a killer... as much as the caps, sometimes more!

drpat said:

The newer pio caps that I tried (audionote, jensen, etc.) all sounded faster and more detailed than the older ones. Sometimes you'll want that, and sometimes you won't. I've done a lot of experimenting with those old Russian PIO caps, and wouldn't hesitate to use them on the Pultec circuit that you're planning to build. Especially the green ones on the low boost bands.

Click to expand...

Thank you, Dr Pat.
I have been fishing for just such an informed opinion!

After spending much of yesterday researching the subject,
I have concluded that CCCP PIO caps are (more than likely)
a great deal and will be very welcome in my Pultecs.