Gates Radio 7X tube preamp

kevinc said:

I should have written that the LL1680 is a good candidate for the output transformer and it's available gapped for a wider range of currents than just 5mA. 

Click to expand...

Ah, thanks, that I hadn't seen. 

I have heard nothing but glowing reports about amorphous iron types, but haven't heard any myself. 



Here's a case I haven't quite grasped yet, a rarely seen approach that at least RCA took a number of times with audio amps. 

Direct feed output transformer with an additional 7K7 ohm choke, directly in series with the primary.  50K in parallel with the choke.    Choke and transformer in the same case, so definite purposeful design.