PB's summary is pretty accurate. That said, I hope we will continue to explore filament power schemes. I feel that further research will pay off.
Now don't start asking "when?!?!?" - this will be a long term project. I think if this preamp is successful, there will be a revision in maybe 5 years. That's roughly the schedule for Foreplay - a new version every 5 years or so.
The BeePre was launched on October 12, 2012 with the web page on the BH products site.
It has definitely been successful!! Congrats PJ!
Just a thought starter!!
Cheers,
Geary