Cmach ,The difference between the Art 2 and 3 is the use of teflon caps , a new and improved power supply as well as a new circuit board layout. There are also improved rear connectors. Yes , 6922 tubes .
Hi Nickt , the preamps I have used have been the ARC Ref 2 and 3. Classe Omega , Aesthetix Callisto Sig , Hovland HP 200 , Cary spl 98 , Spectral DMC 30 sl and Vac Phi 2.0 .
Tomryan . The new designs employing the teflon caps and new topologies have bridged the gap between the lush romantic CJ gear of old and the detailed sound of say ARC Ref 3. In my view , its the best of both worlds.