Hi Don,
As good as those tubes are out of the box,the black bottles will take a while to burn in,around 500+ hours but are well worth the wait.
I am using Pearl tube cooler/dampers with my Franks. The help to reduce the microphonics and you really feel the heat coming off the tubes. Israel recommended them when I was experiencing a slight microphonic issue after going to the treasures from the Full music carbons.
After borrowing or audititioning different interconnects from MIT's to Nordest and a few inbetween, the Coincident Extreme interconnects worked the best for me. They sound like they are not there is the best way to discribe its effect on my system.
After that I went for Extremes from power chord to speaker cable. The intial interconnect switch I made, had the biggest impact for me.
I would love for you to hear those amps with a high efficent speaker of 94+ with a stable impedence curve. That would really display the dynamics of these 300b`s
Glad you are enjoying these special amps. After nearly three years I look forward to listening as much as I did when I first got them.
Regards,