Audible Illusions Modulus 3A noise

Best advice is buy a replacement tube from a dealer that tests for shorts, Gm, and noise. It's only a few bucks more per tube. 

If it uses 6922 like most of their gear does then i would suggest Gold Lion 6922 phono pre grade.  6922 are hit or miss.   The NOS are rare and expensive and honestly many are strong "pulls" from 1960s and 70s lab and medical equipment. It was used in test equipment before audio and many "NOS" are just nos testing used tubes.    Don't waste  money on those .

JJ tubes are good, like others the 6922 is hit or miss. Best to buy screened for noise also.    I had a CJ preamp that was tough on tubes and only two types lasted.   Gold Lion 6922 gold pin and genuine Volkshod Rocket label from the mid 70s.  I have a pair of those in my DAC and they are great if you can find them.   Still I would recommend new GL for that pre.   

Is it new or used?   

It is used 

6922's can be very noisy.  I have had good luck with a lot of the older tubes.  I don't use the term NOS because they are almost non existant.  what most sell as NOS is just a used tube that tests well.  which is really all you need.

I haven't had much luck with the new production inexpensive tubes. 

I don't know that pre, and in that price range is is likely mass produced PCB based, but assuming it doen't have design or build problems, tubes can be found that are dead quiet. 

Good luck,

Jerry

I have owned 3 AI tube preamps since 1994.   I had the original Modulus 3, the 3A, and the 3B. None of them gave me tube noise or hiss.  The key is to get your tubes directly from AI,  or find matched sets of 6H23NEB tubes for the preamp, they are very rugged and quiet   You may find them at the Tube Store or from Upscale   Your noise will disappear like magic, poof