Cap Tone: Film vs Aluminum vs Ceramic

[robotboy]

Hey guys,
I've been using polyester film caps whenever possible as is recommended in the FAQ, and I like them mainly because they look cool and "vintage". However, I was wondering if anybody has done any real world comparisons to compare the tonal differences between polyester, aluminum and ceramic caps. How much tonal variance is there between these materials, and what are the general characteristics of each? I've seen Aron say, "use film for a smooth mellow tone". Does this mean that aluminum would be better to use if I want a harsh gritty tone? Anyway, just curious.

[petemoore]

Geo is a fantastic source for info, reading there will answer a myriad of other questions, and there's also an article on cap tone 'or cap distortion there.
 I'd rate them like this for 'accuracy', but there are tolerance specs you can read on these caps also.
 Metal Film
 Polyester Film
 Carbon
 Swapping 1 caps type, I wasn't totally certain I could hear a difference, from carbon to MF or Poly caps.
 Swapping all the signal path caps in a circuit that has more than a few, I'm dead certain I could hear the difference.
 I like the sound of Poly's and MF's...but will use carbon in a pinch...for something like a LP filter though, say on across a FF's Q2 C/B connections, I Definitely can say the carbon, [as close to the same  uf value/amout of HF rolloff as I could ascertain by ear], definitely the film or metal cap there had a less frizzy buzz tone.
 My tests tend to be made at less than 'laboratory conditions'...I've never bought a new carbon cap, all the ones I've tried are out of old Electrojunk.

[Paul Marossy]

It depends on where they are in the circuit and what their function is. Low voltage ceramic caps are the worst - very non-linear. Yet, at the same time, they can give a nice crunch sound sometimes. If I have to use a ceramic cap, I'll go with 1kVs because they are way more linear than low voltage ones. Film caps are generally well suited for stompbox circuits. Electrolytics seem to make things sound more muffled, and tantalums sound a little more "gritty".

There was a real good Steve Bench page about the sound of caps and a comparison of linearity between different types of caps, but that page apparently doesn't exist anymore.  

Ultimately, this is also a very subjective topic, so if you ask ten people for an answer, you'll likely get ten differing answers.  :wink:

[Dai H.]

best to try different ones yourself in a variety of situations from fuzz box to mixer to whatever. Guess it all depends whether some cap type sounds good or not. For example, it seems I kept assuming that my temp. compensating ceramics would sound better than the cheaper ones, but now, I think I like the cheaper ones for some things better.

[robotboy]

Thanks for the replies guys. I have a big bag full of mylar caps. Are those the same as polyester film for the most part?

[Dai H.]

mylar = polyester. Mylar is a trade name owned by Dupont, iirc.