New cathode bias 6L6 issues...

[EFK]

I'm wrapping up a pretty simply build with 1 channel, single input, (2) 6L6 and a GZ34 rectifier. PT is 300/0/300. I have not wired in the dropping resistors yet as I wanted to just check the B+, so for the moment the (2) 12ax7 have no power to them. I am getting weird voltage readings on the rectifier (5V filament wires to pins 2 and 8, PT to 4 and 6, standby switch to 8): when I power on, before hitting the standby sw., I get 140V AC (!!!!!) on 2 and 8. ??? Once I hit the standby, the AC on the rec filements drops to 11.5 V AC but that's still too high. The 6.3 V filaments are all working normally, I've got 375-380 B+ on the power tubes pin 3 and 340 on pin 4. Also, something weird is going on - I think - with the cathode bias. I'm using a 330 ohm shared resistor w/ a 100uf cap, and there is 109VDC on the tube side of the cathode resistor. That does not seem right! I've gone through all the wiring a few times and can't find anything wrong - yet - so any ideas? Anyone?

BTW, I've tried two different JJ rectifiers as well as two old mullards - all get the same readings.

[stokes]

If you are reading that 140vac from pin 2 or 8 to ground,there should be no ground reference on that winding so any ac volt reading you get is erroneous.The only acurate ac reading you should get is measuring from pin 2 to pin 8,which will be 5vac,I would ignore anything you get from either pin to ground.That 109vdc on the cathodes is quite high,something isnt right.Chack that the value of the 330 ohm is right.Can you measure the plate current?

[loudthud]

Is there 0V on pin 5 of the 6L6s? Otherwise check the resistance of the 330 ohm resistor. Ohms law says 109V/330 ohms = 330mA and 36 Watts.

[loudthud]

SECOND THOUGHT: If there is no connection to pin 5, it still might measure 0 volts when you touch the meter probe there. This is the classic case of the meter changing the circuit you are trying to measure. The meter's input resistance would alter the circuit and pull the pin to ground. You should have your "Grid leak" resistors connecting the pin 5's to ground. Without them the tubes might do some strange things and give the readings you are getting. Check the presence of the grid leak resistors with your meter's ohm function.

[EFK]

Hey guys, I want to thank you for the responses. I guess I had a 'duh' moment and forgot about just measuring between the two rec tube pins: have 5V no problem. Also, as it turns out after I double and triple checked the wiring, I did have a few mistakes which I got all sorted out. Been a while since I messed with cathode bias. Everything working right now - thanks again!