Subject: SE / PUSH-PULL
First of all kudos to you and to your fine magazine. At first, I only understood a third of Issue 1, but now that I just reread it, I understand about 90% of it. I don't know if I will ever hit 100%, but I'll try.
So here is my question. I love the idea you have of converting a ST-70 into a para feed, SE amplifier using tubes instead of chokes. I have a pair of MK 3's that I would like to convert to style of amplifier. So my question is: Would it be possible to make the amplifier work like the Nelson Pass solid-state SE, the Aleph, which is SE up to a certain amount of wattage and then switches to push-pull Class A. amplification for the rest of output power? I know the solid-stage guys have a huge advantage in that they are willing to use IC's in the signal path, which we tube purist aren't, but at the cost of less design flexibility. So is this worth pursuing? Thanks in advance.
I like this idea a lot. It's the best of both designs. But is it doable? I have not seen the schematic for the Aleph and I am not even sure it would help with the design of a tube counterpart; as you rightly point out, we have fewer components with which to play. Still, ingenuity often paints the best design with a small palette.
One point first that needs to be cleared up is that I do not think you have the workings of the Pass amplifier quite right. Yes, it does work in SE Class A up to a certain wattage and