Adcom 565 pre-amp fit here?

I have owned the 565 and used it with satisfactory results. The line stage in the bypass mode is by far the better options. The line stage is good, but what made this a great value was the phono stage. However, this appears to be a non-issue with you. I found it to work well with A.Q. cables. As stated above, it should be a fine match with your 250. I not familar with the all of the variables you have presented and it may be difficult to find someone who has heard this combination as a total system, but in the $ range you are discussing this pre-amp shines above many others. I would highly recommend it unless you are willing to pay more.

I have a similar system to yours and just dug my 565 back out of my closet and put it back into my system and I don't know what I was thinkig before. The pre amp is amazing,but it is a crime not to connect a turntable to it even a cheap one will sound fantastic.I have used the exact same wire,the type 4 and the rubys with great results as well but the aq inter connects can be a little too forward and overly revealing at times.I like the smoothness of the monster 350Is.It is their full range single winding design so the time correctness is more superior to their multiple winding design in my opinion...more neutral and laid back than the rubys you might think you have lost some of the magic at first but you wont experience as much listener fatigue if you know what I mean and if you are using thost cables with that preamp you will.

I recently acquired a second-hand 565 pre-amp for my second system, but have been using it in my main system lately. It's a very good preamp, and the one I have has plenty of depth. Neutral, inoffensive, dynamics are fine. Frankly, I don't see much of an advantage to spending more money on a preamp. I was using an Audible Illusions M3a, with recently renewed tubes, and I don't miss it at all.

If interconnects make any difference at all, the Ruby might be a little closed in, muffled, compared to more expensive AQ cables or the very reasonably priced DH Labs budget interconnect. If the Acurus is bright or forward, the Ruby might do well between the 565 and the amp.