KLUDGE@AGCB1.LARC.NASA.GOV (01/02/91)
On the Grado: Yeah, the Grados have tracking problems. The only thing that I have found which helps is to put a very low-impedance load on them (like 5K ohm). It doesn't help all that much, but it helps some. Also buying the things by the case and handpicking them for tracking works somewhat. On running equipment continuously: One other thing to think about with tube amps is that when powered up and down there is a major temperature difference in the tube itself. Most heater failures occur either at turn-on or turn-off time, and you can increase heater life by never powering down. The question is will it extend anything else (since 6550's usually start sounding oddly long before their filaments go)? --scott