Paper in oil - foil in oil caps

[aclempoppi]

Whoa guys that exchange of opinions about PIO caps was almost as good as a church meeting we had last week. No really, I've never heard folks cussing in church about starting a new ministry for some folks in our town. Oh well, Live and learn. My question to you folks is this; What's the difference between PIO and Foil in oil(FIO) caps ? I ask this because, I R&R some fine sounding Orange Drops for some Alessandro FIO in my '67 BF and '68 retroed SF. Yeah, I think they made a difference in clarity and fuller bandwith definition. But not to the degree of hearing it in the mix on the band stage. So , what's the scoop on these caps? Also,the Alessandros didn't have a country of origin. I remember reading somewhere that no capacitor manufacturer states that their caps are designed to enhance the tone of guitar amplifiers. What about this ? Any and all opinions and experiences on this subject are very welcome! Peace Art

[Andy Le Blanc]

There's two things to remember:

1 Technically a cap is a cap no matter type, kind, or manufacture.

2 ANYTHING you put in the signal path will affect the presentation of the amp.

I love foil, oil, pure metal leads, papers, waxes. But they're perishable to
a degree, the tone ages, not in a a bad way but its noticeable, and there are applications where heat becomes an issue.

[Structo]

As mentioned I think for the most part the PIO caps tend to be leaky.

Probably one of the big reasons they quit making them for the most part.

A film cap is much more stable and really doesn't degrade over time like the PIO.

Then you have the different flavors of film caps, metalized polyester, polypropylene, etc.
Each with their own sonic signature.

[collinsamps]

Whoa guys that exchange of opinions about PIO caps was almost as good as a church meeting we had last week. No really, I've never heard folks cussing in church about starting a new ministry for some folks in our town. Oh well, Live and learn. My question to you folks is this; What's the difference between PIO and Foil in oil(FIO) caps ? I ask this because, I R&R some fine sounding Orange Drops for some Alessandro FIO in my '67 BF and '68 retroed SF. Yeah, I think they made a difference in clarity and fuller bandwith definition. But not to the degree of hearing it in the mix on the band stage. So , what's the scoop on these caps? Also,the Alessandros didn't have a country of origin. I remember reading somewhere that no capacitor manufacturer states that their caps are designed to enhance the tone of guitar amplifiers. What about this ? Any and all opinions and experiences on this subject are very welcome! Peace Art

Who cussed?

[billyz]

I believe the PIO caps use a foil and paper impregnated with oil or Wax as the dielectric. Some caps use a Polyester insulator and Foil. Some use Polypropylene . Also, The conductor can be foil or metalized film. The argument against metalized film is that it get small pin holes ( that are supposed to heal) . Many older caps used a PCB oil with the insulator film and can no longer be made. Waxes are not good in high heat application as you can imagine why.

There are many other types as well. Polycarbonate, Polystyrene, ceramic, teflon, etc. they all have slightly different performances and signatures. Ceramic types are know for the ringing and overshoot of the signal and are considered the least accurate. But many do like the way they sound.

[tweedeluxe]

My experience has shown that they almost always go leaky (on 40+ year old amps), which has always struck me as odd since POI caps are often described as being "self-healing." Anyone know what that means?

[M Fowler]

So why don't we use computer high grade caps in our builts, to stale sounding?

Mark

[billyz]

So why don't we use computer high grade caps in our builts, to stale sounding?

Mark

Computer grade usually refers to the Power supply electrolytics. they were designed for longlife and high ripple characteristics in computer mainframes and make good high voltage power supplies.

[briane]

As a side note my take is PIO really excell in the guitar, as tone caps.

Not so happy with their sound in amps, except for fender style single channel. They just introduce too much feedback.

[Alexo]

As a side note my take is PIO really excell in the guitar, as tone caps.

Not so happy with their sound in amps, except for fender style single channel. They just introduce too much feedback.

Not sure how they can introduce feedback, but I like them in guitar tone circuits too. If you don't think a human can hear what type of cap's in there, try for yourself, this is arguably one of the most sensitive spots in your signal path, and there's no dc, so you can use any old cap, providing you don't get any pcb's on you in the process.

[aclempoppi]

Thanks for the input,you guys! I think the best use will be in a recording enviornment, coupled with Nos tubes. You know what I mean? It seems like, in a live venue the reality of the space doesn't allow the subtle contributions to be heard. I might be completely wrong. But I've played enough tavern and festival gigs to know, trying to get the rhythm in the mix isn't about high zoot amp components. Again, I might be completly wrong. Anyway, it's really neat trying to get these beasts to purr and growl with soul, isn't it? Oh yeah, Who cussed? Gill and Ernie, those old fellas are dug in big time. Next to impossible to get them to change a thing, but on the other hand, they're solid folks. Didn't mean to offend anyone. Art

[aclempoppi]

Hey Alexo and Briane, you guys seem to be zeroed in on the guitar side of this equation. I must admit that my strat is the least object of my tone endeavors. Let me give you the state of the axe: '89 amer.strat, double blocked the bridge with two meticulously shaped oak blocks(really,it's been rock solid for 18 yrs.); vintage style Lindy Fralin PUPs; Lindy Fralin blender pot; CTS or Fender vol.& tone pots. I can't even tell you what kind of cap or it's value is on the tone pot. But what brand and values should I be trying. I play blues rhythm - from faux acoustic to Stax fills. The rosewood board and the polyurethaned body combine to produce a somewhat dark strat sound. Thanks for any advise! Peace Art

[Alexo]

Hey Alexo and Briane, you guys seem to be zeroed in on the guitar side of this equation. I must admit that my strat is the least object of my tone endeavors. Let me give you the state of the axe: '89 amer.strat, double blocked the bridge with two meticulously shaped oak blocks(really,it's been rock solid for 18 yrs.); vintage style Lindy Fralin PUPs; Lindy Fralin blender pot; CTS or Fender vol.& tone pots. I can't even tell you what kind of cap or it's value is on the tone pot. But what brand and values should I be trying. I play blues rhythm - from faux acoustic to Stax fills. The rosewood board and the polyurethaned body combine to produce a somewhat dark strat sound. Thanks for any advise! Peace Art

Heya, best advice I can give is to plug in different caps and see what sounds best. I tend to like to cut the stock values in half for a less muddy, but more midrangey, rolled off sound, but others may prefer to do the opposite. As for type, again, it comes down to what sounds best to your ears. If you're just buying a couple caps for a guitar, it's not too expensive to get some different types and play around with them.

[Tonegeek]

Guess we are drifting a little off topic by talking guitars, but as long as we are...
I find guitar tone controls nearly useless. I know some folks use them but anytime I use mine (and this is with any guitar, and any amp I have even owned over my entire life of playing) they don't just cut the treble back, but they seem to dampen the note. Its like the sustain of the note is affected. I do cut the values down on most guitars I own, but still I end up not using them. I have tried cranking the treble on the amp and cutting back the guitar tone, but that fails me as well. I did sit in once with a band and the guitarist's rig was a 60's Deluxe (with a JBL!) and an 80's Strat. The treble was dimed on the amp and cut back on the guitar. He also had an MXR compressor in the circuit. That rig sounded great. It was a blues lead monster. I went home and tried the same setup with my Twin and it just did not work for me. I do like using a treble bleed cap/resistor though. It helps clean up the sound when you roll off the volume after a dirty lead. Also, even though I don't use the tone controls, I leave one of them in the circuit as a master tone control. I tried removing them altogether once and for a Strat at least, it made the guitar sound tinny.

[billyz]

Just a side note. Since the discussion got onto Guitar Caps. Fender used Ceramic tone caps in their guitars starting the the late Fifties. Fender almost always used a .05 or .047 tone cap. some people like .03 or even .02 in a Fender. Gibson used .02 or .022 caps mostly Bumble bees up until the mid 60's.