by Stunch » Mon Aug 25, 2014 1:36 pm
There was mention on another audio forum about omitting some things from the original ST-35, one of them being the 0.1 uF cap at the input. I'm guessing the DIY version does the same thing, or at least it's an option. Someone pointed out that the 33pF/470R combo after the DC blocking cap was basically a low pass filter to attenuate RF, and that this pair could be removed if there was no concern of picking up RF in the area. For those who like less stuff in the way of the signal, this would probably be a good idea. Are there any concerns you would have with removing the cap and resistor? This would then (only) leave the 47KR resistor is series between the input and the grid.