Tube for aesthetix pandora / romulus

Has anyone tried 5751s, such as a pair of Sylvania triple mica black or gray plates, in lieu of 12AX7s in the Romulus or Pandora? 5751s will reduce gain by 30%, but shouldn't be an issue with digital.

The engineer who says tube rolling is rubbish does not have the best ears. Don't feel bad lots of engineers that design don't always have the best ears. Tube rolling is fun and can easily be heard. Try it you will like it. Brent Jesse, Andy at Vintage tube are both good. Don't feel bad about trying ebay. You will save money over the other two people. Make sure they give you at least 7 days to return them if there is a problem. Brent gives you 30 days to try and you can return them for other tubes even if you don't like the sound. I thinks this is great.

Thanks for the info guys. To clarify the engineer never said rubbish at all. This is what I posted:

I just had this tube rolling discussion with an audio engineer who is highly respected by this board who disagrees with MOST tube rolling for a variety of reasons. I don't know the specifics, but it deals with coatings being burned off in the beginning and folks hearing what they want to hear after that.

In the Rhea what would you change and with what to lower the noise floor? I know that it can be a bit noisy compared to great SS. I'll be running the XLR outputs into an Ayre AX5/20 which is DEAD quiet. I'd be interested....

A no brainer choice would be Phillips (Haarleen plant) ECC83--ie 12ax7 European equivalent. Look for the Delta codes from the early 1960s. Google and you will find all the background you need to know. They will beat the Mullards. Thank me later.

And these will lower the noise floor? What other benefits have you heard? I won't become obsessed, however I may be willing to experiment a bit. Thanks