# Cathode bypass capacitor value in a Fender 5F1 Champ-style amplifier

I am building a 5F1 Champ-style amplifier and I am wondering about what value of capacitor to strap to the cathode resistor? I have seen suggestions of 22 uF and 25 uF and I am not sure what value I should use.

• You might want to hop onto the electronics stack for this one as you'll find a wealth of electronics nerditry over there. We're all sound design guys (not audio design). – Mark Jun 4 '20 at 15:12
• Brian - Welcome :-) I recommend that you edit your question and add the schematic image of your amplifier. Thanks. – SamGibson Jun 5 '20 at 13:47
• You're talking about the cathode resistor bypass capacitor. this capacitor needs to be sufficiently large to bypass any AC signal... the exact value is not really important other than if it is too small, it will start creating a low-cut filter. 22u to 100u are common. – MadHatter Jun 5 '20 at 14:46

This results in a higher gain due to no "local cathode feedback". Typically this capacitor just requires. $$\Z_c << R_c \$$.