Seduction + C4S eating tubes. Compatibility?

[tiller]

Okay, paralleled both 3ohm resistors with the 1.2ohm (so effectively .69ohm) and fired it up. I'm now reading 5.4Vdc at Pin 5 referenced to ground, with old EH tubes in place, and 5.7Vdc with a pair of fresh NOS Tesla. I thought for sure it would have gone up more than that.

Transformer is the PT-1 with silver tape around the core, yes.

Thoughts?

P.S. I get the same values when taking the measurement on the hot side of the 10000uf cap as well.

 

[Paul Joppa]

OK - thanks for the numbers; I estimate that you want a 0.27 ohm resistance of at least 1 watt rating. Probably anything 0.22 to 0.39 will be close enough. That should get you 5.7-6.0 volts depending on the tube, and that's my design range for this particular preamp.

 

[tiller]

Thanks for the help Paul. It seems in spec with the new tubes then
I will run it this way until I place an order for some parts in the future and pick up a more appropriate resistor.

Thanks again!

Adam