Audio Research preamps EXCESSIVE OPERATING COSTS

Idea is to use arc stereo preamp in a home theatre system where main speakers can be used in a stereo environment absent interference from an avr.

Well then a lesser model like the LS26, or 27 which only uses 2 tubes instead of 6 could be an option.
I know what your doing I've done it before with my LS26 for movie nights but I would never run the thing all day long for the wife and kids to watch TV with.. However if it is a must then YOU must change preamps plain and simple. There are some out that don't even need to be turned on which will just pass through a signal..
Do some research :)

We could do an exchange if you like.. The tubes on my LS26 are not costly to replace :) It sounds wonder full as well.

Problem here is that tube preamps which keep the tubes off while watching tv are not very good.  Bartlett looked promising, about $9k, but it didn’t seem to be of same level as the arc 6se preamp.

I have since found that replacing tubes of 6se are about $300 (1 to 2 yrs) and exp for electricity is about $60-80 annually assuming a watt level of 130 while on.  It is truly a pain that a very sophisticated industry has not done a very good job integrating ht with stereo preamps.  McIntosh efforts are very troubling, their system when wired as they want it will cause your avr to turn off so you can’t watch a muted active tv screen like a sporting event or have it displaying stuff during social events.

I want exceptional sound when I listen to stereo, and the hifi industry does not make it easy to get there!!  Just horrifying.

ARC has done their job and produced an extremely high quality stereo component for "stereo use". Being  as nice as they are they also gave you an option  for the home theatre bypass option to use I would guess once in while for the odd movie or sporting event. The problem here is that you want to use it all the time like a receiver.. 
It wasn't built for that..
You gotta make a choice here --  suk it up and keep buying tubes or get another room for the system or like another poster here mentioned get a nice sound bar...