Capacitor types

[JeffYoung]

I agree with ej25awd -- C29 is a bypass on C22; C22 sets the capacitance and C29 broadens the frequency envelope.

But why not just replace C29 with a 1uF polyester along the lines of: MKS02-1/50/10 WIMA | Mouser Ireland? There's no need for a ceramic as well, is there?

 

[ApolloZhang]

Perhaps try some low-Z Aluminum caps instead? At least they don't blow that severely. For example, Nichicon ZLG and ZLH have pretty low impedance.

 

[reedcat]

Sorry for hi-jacking the thread but the subject seemed appropriate...

What capacitor type should I use for C328 in the uPC1237 overload protection circuit I am building?

Ceramics OK or should I go with something more fancy? Will it affect the audio in any way? The output from Q315 goes into the IC....

 

[MarcelvdG]

Ceramics preferred, I think. It is probably either meant to suppress any RF interference picked up by the loudspeaker leads, or to prevent rectification of the AC current through the collector-base capacitance of Q314. In either case you just need something with a very low impedance at high frequencies, so a ceramic cap should do fine.

 

[dotneck335]

Well, a ceramic disc 220pF costs 25¢; a polypropylene costs 38¢. I'd sure as hell want polypro over ceramic in ANY circuit path.