Removing cathode-bypass capacitors, and compensation - diyAudio
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Old 3rd July 2012, 10:02 PM   #1
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Join Date: Jan 2011
Location: Columbia, MO
Default Removing cathode-bypass capacitors, and compensation

What considerations are there when removing bypass caps from preamp stages?

I've removed a 22uf cap from a section of a 12ax7, and simultaneously changed the 220k plate resistor to a 100k (with 1.5k cathode resistor). I've seen that the output impedance goes up, and I've adjusted the value of the (de)coupling capacitor to keep the desired frequency response going into the next stage. But I'm wondering what other effects of "loading" should be considered.

I'm partially writing this post because, though I can find tons of posts on removing/not removing the cathode bypass caps for tonal modifications, I've yet to run into any information on the importance (or lack of importance) of adjusting for the change in output impedance.

any thoughts?
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