Johnman1116 ... The 12AU7 may have spiral filaments. I think the EH 12AU7's do in fact. These tubes dont glow like a lot of others. Im not using any right now in any of my gear but from memory, I think you should probably be able to see some glow if you look down the top of the tube. Point being, just because the tube doesnt appear to be glowing, doesnt necessarily mean it's a bad tube or the cause of your noise. It may be the cause, glowing or not. Or, it could be the 6080 that is noisy. Or it may not be tube related.
Since your resistances and voltages checked out, I would probably try swapping tubes to see if you have a noisy one. It's quick and easy. But you may get advice from the gurus for other things to look for. Regardless, it's always a good idea to have a spare or two of each tube. Even if they arent expensive, boutique tubes. 12AU7 and the 6080 (or 6AS7) tubes can be bought inexpensively. I would consider getting a spare or two of each. Even if it doesnt turn out to be a noisy tube, you will probably find yourself needing one of the spares at some point. Good to have on hand for replacement without down time (waiting on a tube to be shipped to you) and quick troubleshooting.
