Hello all,
I've been busy learning and planning in preparation to build my first SSE. Most of the board components are on the way. In haste, I went ahead and ordered 2 560 ohm cathode-bias resistors, however this doesn't appear to be the right choice for the voltages, tubes and OPTs I plan to run (EL34 at ~450v into 5k).
George's simulations seem to indicate that a 560 ohm cathode-bias resistor (red) will result in 28 watts of idle dissipation, which is well beyond the class A spec for an EL34 (25 watts).
It looks to me like a 750 ohm resistor (green) is the best bet. Idle dissipation of 22 watts, slightly higher 2nd order harmonics - however considerably lower 3rd order.
Is there anything I am misunderstanding here? I know these are only simulations, but if they were totally useless and misleading I don't think George would provide them on his site.
I've been busy learning and planning in preparation to build my first SSE. Most of the board components are on the way. In haste, I went ahead and ordered 2 560 ohm cathode-bias resistors, however this doesn't appear to be the right choice for the voltages, tubes and OPTs I plan to run (EL34 at ~450v into 5k).
George's simulations seem to indicate that a 560 ohm cathode-bias resistor (red) will result in 28 watts of idle dissipation, which is well beyond the class A spec for an EL34 (25 watts).
It looks to me like a 750 ohm resistor (green) is the best bet. Idle dissipation of 22 watts, slightly higher 2nd order harmonics - however considerably lower 3rd order.
Is there anything I am misunderstanding here? I know these are only simulations, but if they were totally useless and misleading I don't think George would provide them on his site.