Aion Lithium - what does this cap do?

[pmerritt]

Hi everyone,

I’m cranking through a bunch of pedals for the holidays. The current one is the Aion Lithium chorus. I’m wondering what c12 does (schematic attached). Lo and behold, I’m crushing along only to find out I don’t have any 180pF caps. I tried soldering a couple together in parallel to give me the right value but that didn’t work out. To get the pedal going I stuck a 100pF in its place and it works now. What happens when using a lower value cap here? Is it an audible difference? Should I use a 220pF?

Thanks for the help and happy holidays!!

 

[benny_profane]

It’s part of an active low pass filter that performs a band pass anti aliasing function.

Given those cap options, I’d use the 220pF. If it’s performing okay and you’re not getting any clock artifacts, you could be fine with the 100pF.