In Reply to: Yep, triode, sounds amazing. posted by Chris O on October 7, 2011 at 11:26:33:
"It is why I chuckle at a 12AX7 driving a low mu DHT."It takes current to overcome the Miller of a DHT.
Even if there were no stray capacitance (and there always is some) the 300B has 75pF of Miller and the 2a3 has more. (about 94pF)
With the 300B, a 50K ohm output impedance (a 12ax7 with 285k plate resistor or a 7b4 like Dennis uses is even worst) the -3db point is 42.44kHz.
So the phase will be disturbed all the way down to 4.244kHz.
There's more to it than that but that alone should stop any 'serious' builder from building that way.Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 10/07/11
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Follow Ups
- RE: Yep, triode, sounds amazing. - Tre' 13:15:44 10/07/11 (0)