This is a circuit I came up with some years ago, based on the cross-coupled inverter; although at first glance, many people thing “cascode,” it isn’t. Note that the FETs are p-channel and configured as source followers. Each FET drives the cathode of one side and the grid of the other. Its great virtue is a low input capacitance, which I leveraged in the Equal Opportunity https://linearaudio.net/article-detail/2170 phono preamp design, published in Jan Didden’s excellent Linear Audio bookzine. Note that the figure he used in the blurb is NOT actually the EO topology!
Besides low input capacitance, it also has excellent common-mode and power supply rejection. This is an early version- I’ve made some improvements which greatly increase linearity and swing. I’m currently doing a more complete write-up on this circuit as a power amp input stage for AudioXpress.
Does this have something to do with “correcting” the non linear transfer characteristics of the 6SL7 tubes with some kind of inversely or, complimentary non-linear transfer characteristic of the 2n5462 ? Or am I missing something ?
Is the gate voltage actually 24 Volts ? Not a tad too high, or am I missing something (again?) ?
Would it work without the input transformer, directly off a balanced XLR signal ?
Many thanks and Best Regards,
How is the revised power amp input stage coming along, any news or details would be appreciated.
It’s a rainy day today, so that gives me an excuse to go do a few measurements and post them. Thanks for the prod!
Hi, visit http://forum.vegalab.ru/showthread.php?t=47852 here you will find a similar hybrid driver scheme and many of its varieties