power rail question

[ernie_jr]

I am looking to build another sunn 200s amp but want to add a second preamp (from an Ampeg B15) On the power rail the last resistor is 33K, if I remember correctly, by adding in another 12ax7 I should make the resistor around 16K to keep the voltages correct. Let me know if I am heading the right way.
Thanks,
Ernie

[Iannone]

That's right.  Ohm's Law - when you double the current (two tubes), you need to cut the resistence in half to maintain the same voltage drop.

[sluckey]

If you do it like this it will not affect the voltages for the Sunn. All you need to do is pick a value for Rx that gives the voltage needed for the Ampeg.

[ernie_jr]

Sluckey,
Thanks taht will work great. The ampeg (if taken off a b26) has about the same voltage as the sunn, so I can just use another 33K
Thanks again,
Ernie