Audio Research D-115 half tube install question


Hi, HIFI folks.
This is my first Audiogon thread, kind of excited.
I have a ARC D115 tube amp, it is very sweet and I like the tube sound. Only thing bothers me is the heat and power usage, it is hot and >5 amp current even at a small level. I use it to power a small bookshelf and the volume is not high as I like vocal music or simple classic.
It has 8 of 6550s, and more than 100w per channel, that is huge for tube amps. I heard from a friend that I can remove half of the tubes if I don't need that much power. I think it is true as it is in parallel push and pull. Just like the D70, uses 2 tubes on each channel.
My question is which 4 tubes I should pull to make it half power. Do I need to do anything else after I pull them? Any shortage or will reduce the sound quality?
Any idea and advise? I appreciate all input.
nhe261
"It has 8 of 6550s, and more than 100w per channel, that is huge for tube amps. I heard from a friend that I can remove half of the tubes if I don't need that much power. I think it is true as it is in parallel push and pull. Just like the D70, uses 2 tubes on each channel.
My question is which 4 tubes I should pull to make it half power. Do I need to do anything else after I pull them? Any shortage or will reduce the sound quality?
Any idea and advise? I appreciate all input.
Nhe261 (Threads | This Thread)"

That's a really bad idea. That trick doesn't work on every amp, and if it did I would still say not to do it. You bought a big tube amp and you're experience is no different than anyone else's. If it bothers you that much, sell the amp and get something different. The only thing you may be able to do is lower the bias. But before you do it, you'll need to confirm that its OK to do so. I don't know enough to say for sure.
I think it sounds like a bad idea too. I would definitely contact Audio Research before removing any tubes.
Sounds to me like a good way to wreck your amp. Don't do it before calling ARC.
Real dumb move.
"03-20-15: Ebm
Real dumb move."

I love reading your long, technical posts. Where do you find the time? Anyway, we have to give the OP some credit, because he didn't make the dumb move just yet.
Thanks for all the good advices, sounds like a dumb idea. That's why I always think about it but never tried. Afraid of smoke and fire.
Amazingly, I once removed half of the 4 power tubes in a Fender Twin Reverb
guitar amp and and it still worked fine, albeit not as loudly...we didn't know...I
would never do that today.
An amp has to be designed in a way that allows it to be run only partially tubed. Atma-Sphere amps, for one, are---ARC's are NOT.