Well, as far as time on the tubes, I changed my last set out when the hour meter on my projector, that I installed and turned on at the same time that I installed the 75SE, hit 3750 hours. Since there's no hour meter on the 75, 4500hrs was my estimate, since I listen to plenty of music without theater. Could have been more. The guys at Audio Research suggested it was time to swap 'em, so I called Upscale for some new ones.
My speakers are 97db efficient, and the Amp only dives the highs/mids, so if I see 5 watts on the needles it's LOUD.
In other words, the tubes are never stressed.
I run a set of 6H30DR true Super Tubes for twice that, so they'll get swapped to new 6H30DR's when the 150's get up there again. The DR's have a 10K hour rating from what I read. I swap the DR's in my preamp at the same time. No strange noises, and the big tubes never stray out of bias.
If you guys think I'm way out out line, I'm listening...
My speakers are 97db efficient, and the Amp only dives the highs/mids, so if I see 5 watts on the needles it's LOUD.
In other words, the tubes are never stressed.
I run a set of 6H30DR true Super Tubes for twice that, so they'll get swapped to new 6H30DR's when the 150's get up there again. The DR's have a 10K hour rating from what I read. I swap the DR's in my preamp at the same time. No strange noises, and the big tubes never stray out of bias.
If you guys think I'm way out out line, I'm listening...