12DW7, 7247, ECC832 -- A Cool Tube!

[9thwardoutlaw]

How well would this tube work for the cathode follower in a Sound City 200 head?

[Guitarist]

I think adding one of these would give you more lows and you could swap in a lower K MV pot for less dulling at lower values. Perhaps even a 100K, though 250K might be decent. Might be a better idea for bass or a Strat. You could add a DPDT switch for alternate biases (plate and cathode) so you could match the tubes better. Adding a 22k in // to the 100K would near-double the current rating which the tube would see. On the cathode try 500Ω // with 1K. Or am I off with these values?

[Wombaticus]

Older Ampeg amps used these tubes.
You run your hand over the tube & they hum.
Tap them & you can really hear them rattle.
And these are NOS tubes!

I've used the new production JJs quite a bit, and haven't noticed any particular tendency to microphonics. They're quite handy for implementing tube effects loops.

[9thwardoutlaw]

I think adding one of these would give you more lows and you could swap in a lower K MV pot for less dulling at lower values. Perhaps even a 100K, though 250K might be decent. Might be a better idea for bass or a Strat. You could add a DPDT switch for alternate biases (plate and cathode) so you could match the tubes better. Adding a 22k in // to the 100K would near-double the current rating which the tube would see. On the cathode try 500Ω // with 1K. Or am I off with these values?

The cathode has a 1meg on it, so should I use a 500K in // with it?