strange biasing problems

[yeahyeah]

Finished up the amp i was building for a friend, powered it up and checked the voltages- everything looks good.

plug tubes in and start to bias...

one tube is "normal" the other is off the charts at about 77ma

These are TAD winged C's and are supposedly matched. what else could be the problem?

I've got another set of tubes that i know are good, so i will try those when i get back home.

[greiswig]

First thing I would do would be to note which tube biases "funny," and swap the tubes in the sockets to see if the problem follows the tube. If it does, I would suspect the tube and not the circuitry. I'd also be pretty quick about flipping the standby switch on and off, to make sure I didn't inadvertently toast a set of tubes.

[Bob-I]

I'd also measure the C- voltage on the grid of the tubes to see if they're equal.

[JammyDodger]

To All,

I second that, swap the tubes and re-measure. I just bought a matched quad of Winged C's and after I plugged them in, found one of them was DoA!

Cheers, Mike

[yeahyeah]

turned out to be a bad DMM.

The amp was fine.

sounds good too.