The new design has two main features - DC filament power for lower hum, and a bigger heat sink for better reliability. It may have film caps for reliability as well; that depends on where Doc B wants to position it, which depends on who we expect to be the customers. If the hum is no problem (it seems to run around 1mV with good 45s, which is actually quite low for an SET) then there would not be a great deal of sonic difference.
The other difference is the OT-2/PC-3 output transformer and choke, which is better matched to the 45 than the original Magnequest iron. I'm not saying my design is better than Mike's (!), just that a 4K load gives better damping than a 3K load.
As for timing, we recently had a great brainstorming session to look at new product development for the next year or two. We haven't documented the results or made all the decisions yet, but we do have a general idea of where we want to go. I can't be very specific yet, but now that the BeePre design is pretty much finalized, the DAC is the next priority. My involvement is just the analog tube output and power supply and won't be so all-consuming, so I'll probably work on the SR amp at the same time.
