Why 6H30 Tubes?

My 2 cents - I have owned several products with 6h30s during the last years:

1. They last between 5000-10000 hours
2. They are rugged and reliable
3. The 6h30 has low plate resistance
4. Good quality ones are easily available and inexpensive.

>However, it has commensurately high current demands on main
>B+ and heater supplies, so costs are roughly comparable to
>a unit using three to four 6922s for each 6N30P.
Shure, and using 4 tubes in the ACT2 compared to the 10 of the ART increased reliability and tube maintenance.
I owned (and loved) an ART series 2. But sometimes one of the 6922 intermittently became noisy and the only solution was discarding all the tubes or spending one week listening for noise, not to the music!