Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: catnine on July 21, 2011, 03:08:19 pm

Title: You know when I was asking about the large filter cap on my AA764 build?
Post by: catnine on July 21, 2011, 03:08:19 pm

As if who could forget . I ask this one question. One mod was to add a small cap across either of the 100k plate resisters for the 12ax7 to tame some highs . Now if the filter cap size has no affect on tone and since the 100k ohm plate load resister is off the B+ rail where is the difference and I am only going by common sense here not facts . Is it because a cap across the plate load resister is down stream and affects the the freq response of the plate on the 12ax7 . Is it because low frequency passes through a resister easier than through a cap?

Title: Re: You know when I was asking about the large filter cap on my AA764 build?
Post by: VMS on July 21, 2011, 03:52:37 pm

http://ampbooks.com/home/amplifier-calculators/plate-bypass-capacitor/ (http://ampbooks.com/home/amplifier-calculators/plate-bypass-capacitor/)