trouble wiring up heaters

[EETStudent]

I have an amp that uses both 6EU7 and 12AX7 tubes and Ive run into a heater problem. Ive started adding another 12AX7 and i just cannot figure these heaters. There used to be a 6eu7 in its place, but Ive redirected the wires and relocated the heaters for a 12ax7. obviously, the 6eu7 already had the 6.3v across the heaters so i just moved those to pins 4 and 5. I figured I would just take a jumper cable from the center tap of the other 12Ax7 and send it to the CT of the new one. Well with that arrangement, only one of the heaters works. Ive tried just a couple other things but no luck. any help here?

[52 Bill]

...so i just moved those to pins 4 and 5.

The heaters of the 12AX7 are not "center tapped" as you called it, unless you are running them at 12 volts.

There are two 6 volt filaments (pins 4-9 and pins 5-9, each of which share a common connection (pin 9). If you want to use 6 volts, the two filaments need to be wired in parallel, so tie 4 and 5 together as one terminal, and use pin 9 as the second terminal.

[Enzo]

SO in a mixed tube amp, the 6VAC goes to pins 4 and 5 of the 6EU7 and pins 9 and 4/5 on the 12AX7s.

[Wakculloch]

Or even pins 1&2 on a 6eu7.

[Enzo]

I'm sorry, I wasn't thinking. Pins 1 and 2

[EETStudent]

ahh thanks guys, got it all worked out.