SE Mosfet line stage with transformer output

[andyjevans]

I build with tubes and am fairly new to solid state. Can anyone suggest a simple SE line stage with gain using one Mosfet that could be used into a line OPT which would act as a phase splitter and give balanced output to a power stage?

I'm particularly interested in the latest Mosfets, and specially the Semisouth devices which can be used at 300v HT supply or even more. I have various interstages like Lundahl LL1671/PP, LL1660/18mA, LL1692A/10mA

SiC Transistors | Semisouth Laboratories, Inc.

I'm sure there's a simple circuit possibility for the above SIC devices, I just don't have the familiarity with biasing such devices. I can use my tube preamp HT supply, but my available transformers stop at 18mA gap. I'd also welcome suggestions for other transformer outputs to use with such SIC devices or other good sounding Mosfets at various supply voltages and currents. My goal is balanced out, but I'd prefer a single device so I don't need to match them.

Andy

 

[AndrewT]

Use a SE to balanced output transformer.
But are they rated for approaching 300Vdc?

 

[andyjevans]

Yes - if you look at the Lundahl site you can see the specifications. The interstages I have are all for valve gear. So the SE primaries are rated for typical valve use - up to 18mA current. That's why I was considering Semisouth parts at higher voltages. Unfortunately they don't have sets of curves like valves do so you can't see bias voltage and current at e.g. 200v or 300v.

I suppose parafeed would be an option for the primary, though I'd prefer to avoid it.

Andy