by EWBrown » Tue Feb 28, 2012 10:15 pm
I've had good results with 6S4As, use a B+ around 325V, plate / cathode current of 25 mA, Rk should be 390-400 ohms, 2W, bypassed with 100 uF / 35V caps. This is the "magic sweet spot" for these tubes.
OPT primary impedance needs to be 10 to 12K ohms, in order to play well and sound best with the fairly high (3700 ohms) internal plate resistance of these triodes..
Run them in parallel PSET, then a 5-6K primary OPT would work well, and deliver 2X the power.
HTH
/ed B in NC
Last edited by
EWBrown on Wed Sep 11, 2013 2:48 pm, edited 1 time in total.
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