Zen amp volume add-on?

Here you go.

Remove R9. Replace with this (see attached image).
Wiper of 25k Potentiometer (middle pin) is connected to C6

There is one possible draw back from doing this, that is the input capacitance of Q1 is a little high and the output impedance of the pot creates an RC filter at input, so bandwidth will be reduced a little bit. Maybe not significant, too lazy to do the calculation.
That is why we use the buffer on an amp like this, since input capacitance of a small signal jfet is much lower, so is not affected by the output impedance of the volume pot, and the jfet provides a lower output impedance than the pot alone does, so can drive any amp without affecting bandwidth too much.




Just to be sure we are talking about the same amp, I have attached link.
http://www.firstwatt.com/pdf/art_zen_amp.pdf
 

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  • Volume Control.jpg
    Volume Control.jpg
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