Def2 had a slightly reticent character compared to Def1.5 before it. Simply installing the nano FRD or even the 2010 HO FRD to stock Def2 shifts the presentation of the speaker to a more vivid, forward sound comparatively. This is good from an ultimate fidelity standpoint but whether one likes it better without going all the way to Def4 and the benefits of the Radian 850 and cabinet improvements is quite subjective. The major revisions to Definitions from Def1.5>Def2 in cabinet construction especially made Def2 the most forgiving of the Definition versions until Def4.
Putting the hotter FRDs in Def2s change the sound profile enough that if you do it, you should plan on having to work back through the gear chain prepared to make one or more adjustments. It could be minor, like changing tubes or it could be major, perhaps changing power amp or DAC. These speaker models are integrated designs so making incremental sub-assembly upgrades necessarily disrupts a balance intentionally achieved earlier. Also the newer FRDs take lots of time to settle in.
I am sure Gopher's concerns will end and he will get back his briefly-achieved system synergy. Some patience and experimentation will be needed to pin it. Going from Def2>Def4 I changed my preamp, for example. There was nothing wrong with my Klimo Merlino Gold +, but it's slight forwardness which was so complementary to Def2 was not quite as well matched to the midrange of Def4 as my Melody Pure Black 101 -- *in my room*. Point is, there are some general guidelines for making these incremental upgrades work, but you really dial them in by working with the specific context of your room, system components and your own emotional triggers for satisfaction.
I got but did not choose to upgrade my Def2s with the 2010 HO FRD, for example, because after having extensive exposure to a friend's Def2s that were built with HO drivers I concluded that in my room I was better off waiting for Def4. In Gopher's case I know that specifically putting nano FRDs in Def2s will remove Def2's forgiveness of the glare in the "A" version of the 211 or 845 power tube. It's his place to start the upstream adjustments.
Phil
Putting the hotter FRDs in Def2s change the sound profile enough that if you do it, you should plan on having to work back through the gear chain prepared to make one or more adjustments. It could be minor, like changing tubes or it could be major, perhaps changing power amp or DAC. These speaker models are integrated designs so making incremental sub-assembly upgrades necessarily disrupts a balance intentionally achieved earlier. Also the newer FRDs take lots of time to settle in.
I am sure Gopher's concerns will end and he will get back his briefly-achieved system synergy. Some patience and experimentation will be needed to pin it. Going from Def2>Def4 I changed my preamp, for example. There was nothing wrong with my Klimo Merlino Gold +, but it's slight forwardness which was so complementary to Def2 was not quite as well matched to the midrange of Def4 as my Melody Pure Black 101 -- *in my room*. Point is, there are some general guidelines for making these incremental upgrades work, but you really dial them in by working with the specific context of your room, system components and your own emotional triggers for satisfaction.
I got but did not choose to upgrade my Def2s with the 2010 HO FRD, for example, because after having extensive exposure to a friend's Def2s that were built with HO drivers I concluded that in my room I was better off waiting for Def4. In Gopher's case I know that specifically putting nano FRDs in Def2s will remove Def2's forgiveness of the glare in the "A" version of the 211 or 845 power tube. It's his place to start the upstream adjustments.
Phil