Electro Harmonix 6922 pre-amp tubes

I'm using 4 EH 12AU7A tubes in my CAT preamp. They sound pretty good after break in and are holding up so far. They don't sound as good as NOS Amperex, Brimar,  RFT, etc. though, but some of these tubes become noisy quickly. The gold pin EH tubes are cryo treated and are different than the standard ones but I don't know if they sound better. Has anyone tried both types?

I'm sorry. 6922s, but I just started using 2 EH 12AU7A tubes in my CAT and the 12AU7s are the ones I was Talking about in the post above. The 6922s have been in for a while and sound fine. That's what happens when someone is talking to me when I'm typing. Sorry for the confusion.

I've gone thru a lot of EH 6922s in my BAT 3iX.  They always get noisy after 6 months or so.  I've found J/J quieter and perhaps a little better in tone.  I've been using a quartet of Amperex orange globes for a couple years.  Very nice tone and they are still pretty quiet, though I do worry about sourcing these for a reasonable in the future.