Blue coloured HV ceramic capacitors in a tone control circuit

[jackplug1]

Is there any reason not to use this type of small capacitor in a tone control circuit? - they are usually 1or 2 Kv
They are cheap and easily available where as the silver mica type are not.
Usually used in snubber circuits.

[st]

Mojo

[pdf64]

What’s their specification, eg temperature and voltage coefficients?

[PRR]

"Blue" is a dip-coat? What is inside? Wax paper? Formica? Dried lark-tongue?

Can you point to a catalog page?

The 1KV rating is a good sign that they won't blow-up easy, and I am not tooo concerned about Voltage Coeficient on a 1KV cap in a guitar amp, but historically audio-people want to know more than just "Blue 1KV".

[jackplug1]

Blue dip ceramic - 471 2kv printed on the surface, no other information
For use on a guitar amplifier tone circuit.

[pdf64]

In the absence of anything more than the most basic info, the only way for your query to be answered is for you to try it 
Temperature coefficient might be assessed by monitoring the cap’s capacitance value whilst holding a soldering iron in close proximity, so as to warm it up.

[Esquirefreak]

I've been using those (100pF-500pF) blue caps here and there in guitar amps. Like bright caps and on tone stacks. Not that I've done a proper shootout against more expensive parts, but they've been working just fine for my purposes.

/Max

[jackplug1]

Seems like the are probably okay to use in a guitar amplifier

[thetragichero]

i like em because they're cheap and pretty and usually come in high enough voltage ratings to be useful either in the signal path or as snubber caps on rectifier diodes
how do they sound? when i play guitar through an amp with em in the signal path it sounds like a guitar... maybe i'm not a tone connoisseur but as long as it's not leaky and of an appropriate voltage rating a cap's a cap to me