The reissue Tung Sols are a very good current production 12AX7. I find them clean, clear with a strong signal that is full range capable, they rarely call attention to themselves.
Unfortunately the NOS supply of 12AX7s has dwindled and what's left don't look so good or are very expensive indeed. You may have more luck with 5751s which won't give you all of the gain you might desire but have exciting tonal qualities. They have been discussed ad-infinitum, so I won't say more than that you might want to investigate that option. I don't recall hearing them in the Orchestra but Trelja and I have DA-60s (unless he parted with his,) where they are fabulous 12AX7 subs. I will make one suggection. The most bass emphatic 5751 that we encountered was probably the GE Triple Mica Grey plates. They are not as detailed or as good in general as the 5751 black plate tubes tend to be, but will provide as much bass as any will, if you should see a continuing need for it.
Unfortunately the NOS supply of 12AX7s has dwindled and what's left don't look so good or are very expensive indeed. You may have more luck with 5751s which won't give you all of the gain you might desire but have exciting tonal qualities. They have been discussed ad-infinitum, so I won't say more than that you might want to investigate that option. I don't recall hearing them in the Orchestra but Trelja and I have DA-60s (unless he parted with his,) where they are fabulous 12AX7 subs. I will make one suggection. The most bass emphatic 5751 that we encountered was probably the GE Triple Mica Grey plates. They are not as detailed or as good in general as the 5751 black plate tubes tend to be, but will provide as much bass as any will, if you should see a continuing need for it.