Have you used the 6S19P-V/6C19Pi tube as a line stage, driver, or concertina phase splitter?

Douglas, this tube specifically in your Guinevere line stage?

Norris Wilson

Remember, this pipe has a realizeable mu of ~2. Up to 3 if you run a lot of current through a CCS. With R_p of ~500R, and 5W of plate dissipation, it should be an excellent choice for a split-load PI. B+ of ~350, and 3k load resistors.

Or a linestage with ~300V B+ and a 5k plate load. 200V across the load, and 80V a-k, with the rest as cathode-ground.

I am going to use them for a low voltage hybrid cascode as in Merlin v2, with the gates between 30 and 50V. Mmmmmhhhh...creat-a-pentode.
cheers,
Douglas

Mmmmmmmm, the forbiden douhnut!

For low mu valves, it has not been my experience to find close matches easily. For GE 5-Star 5687, they are soo close as to deserve 'perfect', but that's a whole 'nother pipe( errr...tube ).

The mu of 2-2.5 achievable with resistive plate loads is appealing. The little bit more gain than is available from a buffer circuit is just what the doctor ordered. I do hate the idea of throwing away gain like I would if I build around a crappy 12AU7. With the mu of 6 from the 12B4, and 1 from a buffer the 6C19 looks like Baby-Bear's porridge...just right!
cheers,
Douglas