07-26-15: Bifwynne
Knghifi ... not really. The last couple of re-tubes came from ARC because the bias spread on power tubes sourced from a reputable tube vendor drifted too much. Btw, I may have overstated the times tube arcing has taken out bias resisters. I was being conservative and may have overstated the issue.
I have 850 hours on orig KT120s in my REF250 so trying to decide where to buy the KT150s. $1600 from Upscale or $3200 from ARC. Hmm!
I already have NOS TS 6550s, Winged C and 6H30-DR so only need KT150s.
The main point is that power tubes may arc on occasion. The result cold be a blown bias resister. Also, at least with ARC amps, bias needs to be manually checked and adjusted on a periodic basis. This type of care and feeding may make ARC tube amps a non-starter for some. And that is a rational reason to consider another tube amp brand or a solid state amp.
In my case, it's not a big deal. I like the other pluses that ARC brings to the table.
Just saying.
Well, some people appreciate the precision of Ferraris, Porsches ... that requires additional maintenance and some only concern is getting from point A to B. :-)
I've had many different tube amps and they're all PITA compare to SS.