Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: hesamadman on June 26, 2013, 06:51:34 am

Title: what about different value cathode bypass cap?
Post by: hesamadman on June 26, 2013, 06:51:34 am

The marshall 2204 uses a .68uf bypass cap. What about using a switch going from that cap to another of a higher value? What sort of differences can we expect?

Title: Re: what about different value cathode bypass cap?
Post by: jjasilli on June 26, 2013, 07:38:58 am

You should do a forum search.  There are numerous topics & schematics posted

Title: Re: what about different value cathode bypass cap?
Post by: jazbo8 on June 26, 2013, 03:03:58 pm

Larger cathode bypass capacitor -> lower cutoff frequency as shown below (for 12AX7 with 100k plate and 1.5k cathode resistors):

(http://www.valvewizard.co.uk/PartialBypass.jpg)