input tube rolling on manley neo classic 250's

I have not had experience with the 12AU7 family in this amp, but I have had quite a bit of experience with the tube family.

If you wish to read a long dissertation on many different 12AU7 variants, search on Audio Asylum for comments by Robert H. He is very knowledgeable.

In my experience, speaking of NOS tubes without having a good idea of the year of manufacture can be misleading. I have found that things can change within a given manufacturers product.

If you are looking for more on top, in modestly priced tubes you might give consideration to 1950's production RCA Long (17mm) Black Plate White Label 12AU7's. This tube presents a clean and detailed top end. In DAC applications, I have found that it really loves good isolation. If this 12AU7 is too forward, you might also want to try the RCA Black Plate While Label 5814A's.

For the modest cost of many of these tubes, you may want to try a few to get a sense for yourself of the various voicing characteristics.

If I may, I will add a few more thoughts to my previous remarks.

Jafox..thanks for the support...your credentials and experience are well known to those who regularly participate here on AG.

I have no desire to flame any particular tube, because I have seen too many variations, and believe that in some piece of gear whatever tube we talk about may be very good. With that said, and having used a DAC that is very sensitive to 12AU7 selection, in my experience, the Telefunken ECC82 is no more than middle of the road....better than some, but very much exceeded by others.

In my experience, the pinnacle of the 12AU7 family is the Siemens Silver Plate ECC82....it leaves everything else in the dust.

Rediculus, if you wish more information, email me off-line. I can send you a copy of my notes on the family and share some of my observations if you wish.