are multilayer mono ceramic capacitor good for audio? for pedals?

[amptramp]

This is an old article that may apply to multilayer ceramic capacitors as much as single layer because if you need high capacitance in a ceramic device, you will probably be using the highest relative permittivity materials which cause the worst distortion:

https://diyaudioprojects.com/mirror/members.aol.com/sbench102/caps.html

Ceramic capacitors can sometimes act as piezoelectric microphones and translate ambient sound into voltage, meaning that amp that sounds nice in your bedroom is going to sound very different at a gig.

[pinkjimiphoton]

everything i build and have built for years uses mcc's for everything. they're small, cheap, and have the tightest tolerances you can get. leads to repeatable results when making a bunch of circuits.
the electrons really don't give a shit what kind of material the cap is made from, the value is the most important.
there's very very marginal tonal differences that may be apparent in some circuits, but... not really.
the shittier a cap is, and the more it leaks, the warmer it will often sound to folks, but no, mcc's aren't bad to use, they sound great, are consistent, and i use them from pf up to about 10uf in most cases. they've worked great in hundreds of builds.

they CAN be melted easily tho... i use a higher wattage iron (30-40 watts) and am on/off in a flash. too much heat, and they can breakdown easily.

[Kevin Mitchell]

In the world of guitar pedals in 99.5% of applications the material of your capacitors are negligible.

For those who disagree, let the frenzy begin.

[amz-fx]

All ceramic capacitors are not created equally.

Ceramic is a general category name for a large selection of components that use a ceramic material as the dielectric layer. The ceramic is usually modified by the addition of titanium dioxide, barium titanate or other chemicals to enhance its properties, and increase capacitance in small sizes.

Some common types of ceramic capacitors are C0G (NPO), X5R, X7R, and Z5U.

The failure rate of smt capacitors is related to its size and dielectric thickness. For example, as the size moves down from 1812 to 0603, the failure rate increases by more than 10 times.

Higher operating temperatures can cause reduced capacitance, but at the temps in pedals, this is not usually much of a problem.

Also, smaller size ceramics will lose capacitance at higher DC voltages. A 0603 mlcc ceramic capacitor can lose 70% of its capacitance at 50v and the smaller 0402 can lose 90%!  Even at 18v, as you can find in some pedals, the 0402 size will lose over 65% of it rated capacitance and the 0603 at least 25%. For best results, a 0805 or larger ceramic mlcc smt size is recommended for pedals, but you often see the smaller sizes in some designs. (This data from a Kyocera white paper.)

Unless the pedal designer knows what type and size of ceramic smt capacitors are going to be used in the pedals, the actual performance may stray far from the designed target.

Best regards, Jack