Audible illusions Modulus 3A or Klyne 6L

Bigtee,
When purchasing a unit at the level an AI3, you should not have to be advised not to put NOS tubes in it, period ! That is the main reason why AI units loose so much of their value after only a few years when purchased new.

That's unfortunate because they are fine sounding machines.Like you said,if someone does'nt care about anything but tank built tubes to go with it,fine ! But .... Have a look at this:
http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html

I have owned the AI M3 and now the L2. Amazing pre's. Bests my Rowland Concerto in quite a number of ways. As far a quality, never had any problems.

The Klyne can be matched to every amp based on its Gain Potis.
And it is reliable/good sounding.

you just missed the CAT preamp to name three of the mose regarded, sensible choices of preamps - I am sure any of them will match with your described setup with no issues.

The Audible Illusions Modulus L1 (this is the one I own) is identical to the line stage sonics of the Modulus 3A, minus the fact the Modulus L1 does not have a phono section. It was mentioned above that Audible Illusions preamps eat tubes. I think this is because the tubes are constantly on even when the preamp power switch is turned off. This no doubt contributes to excellent sonics from the get-go.

I like my Audible Illusions pre a great deal and I'm just now getting around to tube swapping. I read that Audio Research makes tube rings for the 6922 tubes. Stereophile mentioned the use of these rings do not produce suttle improvements but major differences in most all areas of the Audible Illusions preamp.

Elevick the newer AI units use two gain controls (one per channel) and one master volume. This is very handy when it comes to setting the proper gain for your particular amp. Once set you only need to adjust the one volume control from there on.