A little help on choosing amps

Unfortunately I won't have a chance to demo, so I thought I should reach out on here.

I have the opportunity to purchase a used Pass X150.8 or Burmester 956 MK1 for roughly the same price. Which will synergize better with my system...I'm sure either will be a nice step up from a fantastic, but old, arc d120:

Fostex hpa8 dac
Arc LS 17se
Dynaudio 1.4LE

I mostly listen to minimal, drum and bass, and some rock. Bands like arctic monkeys, Zeppelin, volor flex, etc come to mind. In not a bass head but the music tends to have deep, sustained, bass lines. Im in an NYC apartment so my listening room is pretty small. Also, should I upgrade the dac in particular?

I suspect that the input impedance of the Burmester is much too low to be a good match for the LS17SE.  As with many ARC line stages and preamps the LS17SE has a recommended minimum load of 20K.  The input impedance of the MK2 version of the Burmester 956 is 1.88K balanced and 13.6K unbalanced.  If the MK1 is similar in that respect it would be a poor match for the LS17SE.

The X150.8 should be fine in that respect, with specified input impedances of 100K balanced and 50K unbalanced.

Good luck.  Regards,
-- Al
Thanks for the input. Do you think I should sell the LS/trade out for another pre. It's only a month old so I won't get hosed on it. Do you have a rec in the 2-3k range that might be a fit?

Sound signature wise, what differences would there be between the pass and burmester. I was really intrigued by the burmester being described as fast, transparent, and highly controlled.
I have no particular knowledge of the sonics of the Burmester.  It (or at least the MK2 version) is a fully balanced design, however, and driving it with balanced inputs is highly recommended.  Assuming the MK1 has a balanced input impedance that is similar to the MK2's very low 1.88K, that would severely limit your choice of preamps now and in the future, and would probably rule out the majority of tube preamps as well as many solid state preamps as suitable choices.

Personally I would not want to choose a power amp that imposes such a significant constraint on preamp choice.

-- Al

 ARC and Pass are a very good match. I have heard a Pass 60.8 amps with an Audio Research Ref 5 many times. The Pass 60.8 are one of the best sounding solid state amps I have heard. I am sure the  Pass X150.8 would sound very similar. 
Any thoughts on a devialet Integrated? Not to hijack my own thread but saving some space is a huge deal in NYC :)
devialet (sp?) would also be a great choice. Many owners of high end traditional gear like the pass, arc etc have switched to the new devialet integrated- excellent sounding amp section (an interesting configuration to get the best attributes of diff classes - class a and d I believe. Also includes an excellent dac and phonostage in the same case work which is very attractive. Good luck
I'd Pass on this one.....
I have decided to pass on all 3 for now...the market is a bit thin at the moment and I will reassess closer to the holiday season. Thank you all for your help.

I'll stay away from those tricky Burmesters :D