Here is the response I posted to you on AA. I am copying it here for anyone who cares to see it in this forum.
The JJ is an extremely nice sounding preamp. The phono stage is the star here, it is very good and works well with MM and MC cartridges. However, there is no free lunch.
While I owned mine I developed a channel imbalance which was present only on the phono stage. I had Kevin Carter attempt to repair it for me and he found several issues with the design and build quality. One problem is the 4 6922s that reside (upside down, like two pairs of bats) underneath the top plate. There isn't much ventilation and things heat up quite a bit down there. Not good. And the position of the tubes themselves put quite a bit of stress on the tube sockets. Eventually, the tubes just work themselves loose.
I sold it and moved on. I am very happy with the preamp I have now, but still have fond memories of the JJ. There was nothing special about the circuit or the quality of the parts used, so I have no idea why it sounded as good as it did. You can often find them for 1K or less on Agon. If you can steal one (I paid $700.00 including shipping for mine), then it might be worth your while. Just beware of the issues I have described.
Oz
The JJ is an extremely nice sounding preamp. The phono stage is the star here, it is very good and works well with MM and MC cartridges. However, there is no free lunch.
While I owned mine I developed a channel imbalance which was present only on the phono stage. I had Kevin Carter attempt to repair it for me and he found several issues with the design and build quality. One problem is the 4 6922s that reside (upside down, like two pairs of bats) underneath the top plate. There isn't much ventilation and things heat up quite a bit down there. Not good. And the position of the tubes themselves put quite a bit of stress on the tube sockets. Eventually, the tubes just work themselves loose.
I sold it and moved on. I am very happy with the preamp I have now, but still have fond memories of the JJ. There was nothing special about the circuit or the quality of the parts used, so I have no idea why it sounded as good as it did. You can often find them for 1K or less on Agon. If you can steal one (I paid $700.00 including shipping for mine), then it might be worth your while. Just beware of the issues I have described.
Oz