12ax7 in parallel cathode resistor ?

[jamme61]

In my 18 watt clone build, the V1 is in parallel. Can I go as low as 680ohms on the cathode resistor? its 100k plate resistor thanks

[Stevem]

Yes!

[jamme61]

Lol thanks

[roberto]

Even lower.

[jamme61]

Even lower.

400ohms sounded really good

[David Root]

400 ohms sets a pretty warm bias. Assuming you're using original schem B+ of course, 280V. Not that the value of Rk seems to make much difference in that situation, within reason.

What is your cathode voltage?

[jamme61]

I didn't measure the cathode voltage. I did measure the plate voltage which dropped from 155 - 820 ohm resistor to 143 - 680 ohm resistor to 135 with 400 ohm. I've been playing it with the 680 ohm and liking it a lot.

[gingertube]

Or you can even run the two parallel triodes at different operating points for some harmonic emphasis.

See what I did in my "Junkbox Trainwreck" for an example.
Cheers,
Ian

[jamme61]

Or you can even run the two parallel triodes at different operating points for some harmonic emphasis.

See what I did in my "Junkbox Trainwreck" for an example.
Cheers,
Ian

Thanks I thought about doing this but I know the way I am. I will be tweaking those two cathodes and even the plate resistors forever - which isn't that bad a thing -I do love this stuff. What's the value of the cathode resistor on v1a?hard to see it- Thanks for the info

[Structo]

Looks like 3K9

[jamme61]

Thanks

[sixstringer]

Hey gingertube,
Nice looking hand-drawn schematic, bro