Best small signal tube for a preamp?

Is there inherently a "best" small signal tube for use in a preamp? Assuming all other things are equal-which of course they never are.
Choices are 6922/12AT7/12AU7/6BK7/6BZ7/12BH7/6H30II (and varients to the listed tubes - e.g. E88CC for 6922, etc.).
The reason for my question is that I am auditioning the Lector Zoe, which can use all of the above tubes by way of its SATC ( autiomatic tube adaptation) circuit and user switchable 6V/12V plate voltage.
I am interested in your reason, which might have to do with inherent sonic characteristics, predisposition for problems such as noise or microphonics, or availability and economy of NOS tubes being better for one tube type over the others. All responses are welcome, and in return I will let you know the results of my listening with the different tubes that I try.
Rodman99999, I'd love to hear those Siemens in my Cal Sigma/Delta. But, don't they use 12AX7a? :-)

I use 6h23EB's in my BAT (original version - no upsampling). Do you think there is a significant improvement over these when using the Sieman's you mentioned?.

Do you think these Siemens are rugged enuf for an ARC SP10?

Hi Newbee- You got me there!! It's been awhile since I've owned those CAL pieces and I've slept since then. BUT- You're absolutely right, and what I ended up with in there was the Telefunken ECC803S. If you're looking at that family(12AX7) what I said about the CCa applies here as well. I can't imagine ARC running a bias hot enough to shorten the life of a tube as rugged as the CCa(10,000 hrs expected). If they did the units would positively eat lesser tubes. Honestly- I've never listened to 6H23EBs in my VK-D5. I had Siemens E188cc's in it until I could find the three matched pair of CCa's(a pair from Brazil, and two from W Germany). Had to get rid of those original tubes ASAP(don't want to say, "Russian tubes" 'cause the unit itself was designed by one, and I love it). A less expensive experiment would be to try 6 E188cc's in there. If they are more musical: remember that the CCa's will be another magnitude of improvement. I don't believe you'd be disappointed at any rate. Even after going through finding three matched pairs and at the cost of entry! Happy listening!
Hey- Weren't the 6H23's what came in the VK-D5? If so- I guess I DID listen to them, and started tube tasting right away. One more thing: If you shop for those CCa's make certain you're looking at tubes from the 60's. They have a dull grey plate under the getter support. The ones from the 70's have a shiney plate and will sizzle your ear hairs(of course- some would call that, "detailed")! I you make the switch- You won't be shopping for another CD player for a long time.
My BAT, an early model (1997 I think) came with low noise Sovteks. Not much different (then) from the 6h23's - I thought the 6h23's might have been a tad, no more, warmer/smoother than the Sovteks but I was using them in my SP10 which is reknown for eating tubes (including the Siemens I tried in it - don't recall if they were 'grey plates'). So I gave up on all my fav' 6DJ8's/6922s and balanced out the rest of my system. I never tried Siemans in the BAT - I did notice though that it benefitted from very low noise tubes so I just kept life simple and used the same tubes in it as I did in my SP10. Thanks for the recommendations...........
Keshiri, I ended up taking out the 12AT7's and putting back in the stock EH 6922. Based on my limited experience with the Zoe so far, the 6922 tubes seem the way to go. As HP said, it is sort of fun being able to roll different tubes; but in the end I suspect the manufacturer already did this and put the most compatable tube type in the stock units. That said, I received the Amperex PQ USA White labels this week and burned them in a couple of days, then man oh man, what a nice sound. I have owned some pretty expensive gear, but I consistantly find the most expensive or most highly rated stuff is not necessarily what I like best. To me, this Lector set up (CDP 7TL MkIII and Zoe) is just great - very musical, dynamic, clear, quiet and just plain fun to listen to. I am currently running that front end into Cary 500MB monos and my Aerial 9's. I do have a wanted ad for another preamp (Lamm LL2), one I have always wanted to try, but I am not in a huge rush because everything sounds so good right now. Regarding your Zoe, I would stay with a 6922 varient, and personally I like the Amperex. I have used the CCa's Rodman99999 talks about in a SF Line 3 SE I used to own, and they are nice but maybe a touch on the clear/extended/neutral side of things compared to the better Amperex's which are a little more in the rich/organic/full-sounding camp - both have good bass.