I also have been considering an upgrade to my Jolida. From my research it looks like one would have go an expensive unit such as a Simaudio Nova or Eclipse, Capitole, etc. to obtain a significant improvement. I am waiting to hear one of these pricey units in my system before making that investment.
You can get part of the way there with a few tweaks. One is changing the tubes to a black plate 3 mica version of the 5751 tube. See the following links for discussions on 12AX7 and 5751 tubes:
http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#12AX7
http://www.nickdangerous.com/misc/mghead/
Another tweak is an isolation platform. Mine consists of a partly inflated bicycle inner tube under a plywood board and then three marbles on top of upside down catfood cans. The jolida partically floats on top of this system and the sound is improved in all areas.
You can get part of the way there with a few tweaks. One is changing the tubes to a black plate 3 mica version of the 5751 tube. See the following links for discussions on 12AX7 and 5751 tubes:
http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#12AX7
http://www.nickdangerous.com/misc/mghead/
Another tweak is an isolation platform. Mine consists of a partly inflated bicycle inner tube under a plywood board and then three marbles on top of upside down catfood cans. The jolida partically floats on top of this system and the sound is improved in all areas.