Silver Mica vs. Stacked Metal

[otokomae]

OK, here's a quick question:  I read the FAQ and the RG Keen article on capacitors, but neither mentioned specifically Silver Mica or anything like the Panasonic Stacked Metal caps.  Are the Silver Mica ones better than regular Polyester Film caps from Radio Shack?  What about the Stacked Metal ones?  Do they do anything to improve sound quality?  I heard they're supposed to save space, is that true?  Is there some other kind of cap that deserves mention here besides the regular Poly-Films?  What do you guys think?

[MartyMart]

OK, i use silver mica for all small "pf" values up to 2000pf, usualy to replace small "ceramic" caps as they are very high quality, but remember that lots of good stomp boxes sound great with ceramics !! and siver mica's are quite big.
For larger values ( 0.022uf - 1.0uf etc ) i use a mixture of Polyester MMK's and panasonic ECQ's from smallbear, as they seem to sound as good as "metal stacked" so any high quality polyester or even "greenies" from smallbear should be fine.
Electro's for large values or Tantalums if they are not too expensive.
Cheers,
Marty.

[Steben]

And why is there so much to do around the material of caps?
I mean why does metal sounds better than "stock" caps?
1µF sounds the same as 1µF, no??

[otokomae]

Hmmm...?

[otokomae]

Hmmm...?

[Hal]

And why is there so much to do around the material of caps?
I mean why does metal sounds better than "stock" caps?
1µF sounds the same as 1µF, no??

ehhh....I hate to sound like an audio phool, but i have noticed different "tones" of capacitors.  I'm honstely not sure why this happens, but it probably has to do with frequency pass characteristics or discharge speeds.  

Also, capacitence is not the only spec that matters - ESR, equivilent static resistance (?), although I'm not sure what it means, is mentioned in cap specs.  Another characteristic that varies is leakage.

[Steben]

And why is there so much to do around the material of caps?
I mean why does metal sounds better than "stock" caps?
1µF sounds the same as 1µF, no??

ehhh....I hate to sound like an audio phool, but i have noticed different "tones" of capacitors.  I'm honstely not sure why this happens, but it probably has to do with frequency pass characteristics or discharge speeds.  

Also, capacitence is not the only spec that matters - ESR, equivilent static resistance (?), although I'm not sure what it means, is mentioned in cap specs.  Another characteristic that varies is leakage.

The better the cap, the lesser the ESR and leakage then?
So as I understand well, "cheap" caps are more than just plain capacities?
While better caps are more theoretical caps?

Seems logical after all. ;-)

[bobbletrox]

"Stacked Metal" is just a confusing way of talking about metalized polyester film MTK style caps.  They're exactly the same as "Green-caps" except one is a roll of film layers and the other is a stack/sandwich of layers.  Stacking the film makes it less prone to total failure apparently (which doesn't mean squat in pedal land).

The fancy ones Keeley uses are just MKT caps that have been dunked in goo like Greencaps so they don't take up as much space.  MKTs usually come in tiny plastic boxes that take up a bit more room than dipped caps.

Replacing Electro caps that are in the signal path with film caps makes a bit of a difference to some people's ears...but replacing a Greencap with a "Stacked Metal" cap won't do anything because they're made of the same stuff.

[Paul Perry (Frostwave)]

A possible source of difference in caps, is that some materials (especially the ceramic used in those small sized computer bypass caps) the actual capacitance is voltage sensitive, so the cap can introduce distortion. Which you might or might not want, musically.
one field where caps are completely critical is in radio work, where you might want very high Q coils (so must be very low loss, also temperature stable to a ridiculous degree).

[bobbletrox]

...or maybe I'm wrong.  I dunno!

[otokomae]

So, what we're saying is with regular caps, not electrolytic, etc.:
    Ceramic Caps= Bad (or good to some people)
    Everything Else= Pretty Good, not much difference in pedals?

So, Silver Mica caps really won't show much (or any) audible improvement over the Green Radio Shack polys, but are worth using to replace ceramics?

And what I was saying about the stacked metal caps wasn that I heard they saved space, but sounded pretty much like the regular poly caps.  Is that still right?