Mu Follower Driver for Push-Pull

[scott17]

Thanks Cassiel. I wish you well in tuning your circuit.

I took a few more measurements today.

Right before the output clips I measure 70V P-P driving the input to the cathodyne, and 65V P-P driving the 6CA7s. The cathodyne B+ is 290V.

[scott17]

This is the version with a few component modifications. I mentioned before that my PT is only 200mA, so I had to further modify the cathode resistors for the 6CA7s to keep the current in check. The drivers are about 3mA each & the cathodynes are 3.5mA each.

My function generator square wave has a little overshoot, so that's where some of the overshoot comes from on the waveforms. The 1KHz waveform was taken with a 100pF compensation cap. Changing to 330pF reduced the overshoot and ringing to just about flat. I show the 100Hz waveform with and without feedback. Measurements taken at 2.83V with 8 ohm dummy load.

[scott17]

The plate load resistor for the lower half of the mu follower should actually be about 30K, not 33K.