[HBR] 6SN7 infinite-impedance upgrade for HBR-14

[hbrnut at earthlink.net]

I really don't think this is a big mystery. The 6BE6 is basically a miniature version of a 6SQ7 and a 12AU7 is a miniature version of a 6SN7. I think the builder just used what he had on hand.

73,
Darrell, WA5VGO