Some capacitor questions from a relative n00b

[TheFantod]

I've built a couple of BYOC pedals and a couple of Allum Mods. I'm ready to expand to more DIY stuff, but still using instructions!

I downloaded the Wampler book, and am interested in three pedal mods, all Boss. I have some minor question for each.

1. The DS-1 Keeley mod calls for a 470pf Silver Mica cap. Digikey wants $2.57 for one. Both Small Bear and PPP have Silver Mica caps much cheaper, but neither have 470pf. Would using a different value, say either a 430 or 500pf, make any discernible difference? Also, what makes Silver Mica more preferable over film?

2. The ODB-3 mod calls for 2.2uf caps. From what I've read here, film caps > electrolytic? But 2.2 film caps seem to be pretty big. Is that why bipolar electrolytic is recommended here? Are polarized better than nonpolar?

3. Lastly, the CS-3 mod for bass recommends a 10uf cap. Seems that a 10uf film cap would be a whopper. Use a bipolar or polarized EL again?

Thanks in advance!

[JKowalski]

I've built a couple of BYOC pedals and a couple of Allum Mods. I'm ready to expand to more DIY stuff, but still using instructions!

I downloaded the Wampler book, and am interested in three pedal mods, all Boss. I have some minor question for each.

1. The DS-1 Keeley mod calls for a 470pf Silver Mica cap. Digikey wants $2.57 for one. Both Small Bear and PPP have Silver Mica caps much cheaper, but neither have 470pf. Would using a different value, say either a 430 or 500pf, make any discernible difference? Also, what makes Silver Mica more preferable over film?

2. The ODB-3 mod calls for 2.2uf caps. From what I've read here, film caps > electrolytic? But 2.2 film caps seem to be pretty big. Is that why bipolar electrolytic is recommended here? Are polarized better than nonpolar?

3. Lastly, the CS-3 mod for bass recommends a 10uf cap. Seems that a 10uf film cap would be a whopper. Use a bipolar or polarized EL again?

Thanks in advance!

1. Honestly I doubt that the mica cap would sound any different then a film cap. Some people claim they hear large differences in changing out capacitor types and they may have some basis for that but I have not experienced anything I would call significant. It's probably more because of capacitor tolerances (changing out a 5% cap for another 5% cap would probably mean you are changing the value of the cap). 430pF and 500pF would probably sound a little different but not too much.

2. Typically you try to avoid electrolytic capacitors for everything. They are the worst caps in tolerance, stability, and lifetime. Plus they are polarized which limits their uses. Electrolytics are the only way to get large value capacitors cheaply (10+ uF) and are best for stuff like power supply filters where they don't have to be precise or very stable. That isn't to say never use them, they definitely work and dont necessarily make a circuit sound bad just by putting them in. You can get small and cheap 2.2uF non electro caps though. I personally love monolithic ceramic capacitors, they are very tiny and can be in large sizes. Nonpolar are best because you can't put them in a wrong way, you don't need the voltage to be across them in a certain direction. More usable.

3. This is a job for an electrolytic cap. You can't get film or nonpolar caps for any decent price greater or equal to 10uF.

[tubelectron]

Hi,

JKowalski is right, indeed.

Silver Mica would/may be suitable in audio RIAA tube preamp - the rest is history... The difference may come from the value, not from the technology here, so it's better to stay at 470p, ceramic, film, platinium injected with pyralene, solid gold plus bamboo, or any...

The lytics are the lytics - if they are in the audio path, prefer film (or other) if there is enough room for it. The losses in the highs are greater with a lytic, usually, and their impulse response is often degraded too; non-polarized being the worse.

A+!