diytube.com

Bottlehead just mentioned the 3B7 in one of their custom 2A3 amps, for all-DHT operation.

Loctal base, glass envelope, 1.4 / 2.8VDC filament @ 220/110 mA.

http://frank.pocnet.net/sheets/127/3/3B7.pdf

Looks like it could have some other interesting uses.

/edB

I have that BH amp. I think it sounds wonderful.
I bought another 3B7 for it, but it has a ringing problem.
Don't know if it is oscillating or if tube dampers would help.
Haven't compared it to my other BH amps, it is certianly as good.