Audio Research I/50

That is probably after you install a new tube-set.

@runwell - "And I think it is pretty shorter than normal. But I do not know why."

I believe the higher the bias, the shorter the tube life.

All of my ARC amps had about a two-Year tube life (6550s).

Carver's latest tube amps use a much lower bias and, therefore, have a 5 or 10 year tube-life (depending on model).

Yes. All of these factors figure into the total lifespan. Some more than other. At the time, I was playing music 4-5 hours a day (more on weekends) and got about two years from ARC factory tubes. You can probably compare tube bias to the idle speed on a car. If your idle is set to 4000 RPM, your gas won't last as long.

@runwell - I too owned the VT-100 III. Also the Mk-I and a Classic 60 (the good old days!). I never used them with a preamp that matched their quality, however so never heard them at their best. If you are worried about tube failure, just replace the 6550s after two years. You can send the old set to someone who does testing (like Upscale Audio in L.A. California) and keep the good ones for spares. The 6H30s last a lot longer than 6550 (ask ARC about lifespan). BTW, I had a power tube go out on my ARC Classic 60 and didn’t even notice it (I listen at conservative levels and use a subwoofer). Discovered when I traded in for the VT-100 Mk I.

Can you post a link?

Thanks to both. I'm looking long-term for a small, quality tube amp for my new Klipsch. I'm sure either of these would fit-the-bill. I'd lean toward the BAT (is the ARC triode?). Also, I've always wanted the legendary 300B in my system. Currently I'm "House rich" (small "r") so I don't have to worry about it for a while. I remember when $9000 used to be a lot of money.

 I'm breaking in the Klipsch Forte 4 in my Home Theater system and they sound great! Planning to try them in my music rig shortly. Have a feeling they are going to blow me away! And with 300B or Triodes? Wow.

Balanced Audio Technology VK-3000SE (replaced by VK-3500 which is, I believe, same internals in a new box). I used Audio Research for ten years then switched to BAT and never felt I was missing anything. BAT is just pure music.