Naim DAC v1 and a Linn Majik DSM?

Hi!

I'm new to the realm of nice Hifi stuff so excuse my ignorance.. I recently inherited a Naim DAC v1 and use it on my computers in my studio/game room. I don't have an amp so I plugged my old Harmon Kardon Soundsticks (the ones where the subwoofer looks like an obese jellyfish) into its headphone socket - this gave a huge noticeable boost to sound quality compared to inbuilt sound.. And I've loved the properties of the sound.

Anyway, I just discovered I'm also inheriting a Linn Majik DSM and pair of Majik 140 floor speakers. :-O Which will probably end up moving to the same room. 

is it worth me using the DAC v1 still? Or is the Linn likely to sound better anyway? I live in quite a pokey back to back terraced house.. The Magic DSM only has RCA inputs I could use to get sound in from the Naim.. I'm guessing it's worth getting a DIN to RCA cable if I do end up using it?.. But if the sound is passing through two systems is it going to be processed by both and end up sounding weird? 

In my living room I have a Yamaha surround system.. Would inserting the DAC-V1 into that environment provide more benefit than having the Naim  down with the Majik DSM? I'm guessing that would limit anything I plug into it to stereo. (It has consoles, STBs, blu-Ray connected atm) so that's likely not desirable. 

Thanks in advance and apologies for the noob questions!