SoundMods wrote:
OR -- you could do what Dennis Had did with the Cary CAD-805C and "jump over" the inter-stage transformer with a high quality 2-ufd cap. with a smaller bypass.
It definitely works great as the sound is exceptional. When the 845 output tube's grid starts to go positive with increasing signal the transformer/cap enables the 300B to drive the 845 past that point.
I expect David Berning could explain it better -- but that is a consideration.
The bifilar wound interstage I am using already does that to a certain extent, since there is close capacitive coupling between the primary and secondary windings. Not sure exactly what would happen during the transition to A2, thinking that the inductive coupling prevents the blockage effect across the capacitor when the output tube pulls grid current. So the circuit acts as a cap coupled circuit until then. However, the nice thing about using a FET source follower is the low impedance and drive power, where I have a higher impedance and more limited drive with the 7722 tube.
Still, a good though, and something I could try pretty easily.
David