Audio Research D-250 Mark II power amp. Comments

I am planning to buy the Audio Research D-250 Mark II Servo power amplifier. I am buying it used . Does anyone have any comments on the reliability of this amplifier? I know that the older Audio Research equipment have reliability problems and are very costly to repair. I would appreciate your views. I am purchasing to drive a pair of martin Logans monnolith 11.

I owned one in the late 80's, a very powerful sounding amp, I had it coupled with an Audio Research SP10 preamp on Quad speakers. I used it I guess for about 3 years with no break downs. However, I must warn you, when it comes time to retube one of those things even back then it was $800.00+, (I am sure much more now) from Audio Research and if you do it yourself you must either learn how to rebias the tubes or have someone local do it for you, and I suggest you do it every 18 months. Audio Research says about every two years, but when a Power tube (6550) goes bad in an Audio Research amp things can get a little scary. I had one go south on me in an Audio Research V70 power amp, luckly it only took out a couple of resisters which was repaired locally. If you should ever have to send that behemoth back to Audio Research the freight bill alone would be ???????. One more thing, in the winter you won't have to heat your listening room, on the other hand in the summer..........

I don't know why you would want a 250 watt tube amp unless you are driving some very in-efficiant speakers, that seemed to be my conclusion anyway. That being said I have used Audio Research gear for well over 20 years with very little trouble, but, with any tube gear they just need to be looked after, part of the fun I guess. Good luck with your purchase.....Bob
Thanks. I am asking my self the same question, why do I need a 250 tube amp? I have bought the Cary SLI-80.