Unfortunately I know nothing of your DAC, but I do know the Audiolab M-PWR well. I have two of these. I also have a selection of RCA cables (See quote of me wasting hundreds of £ in another post).
I tried a few entry level RCA cables (CA AUD700, Atlas Element, etc...) on the M-PWR and to be honest it sounded fine with a M-DAC+, and on my Denon AV. However there was little between them.
Looking at the cost of the M-PWR and the attached sources, I didn't want to go overboard on the RCA cable and ended up with a QED Reference 40 RCA. The improvement in sound is notable. I expected better high end, but what I actually got was deeper, clearer bass.
I have a small family, so spending £120 on a 1m cable (paid £110) used in my study needed to be justified in sound quality. I don't believe it was money wasted. But I don't think I could justify spending much more considering the cost of the attached source and amplifier.
In my very humble opinion (which is likely to draw a lot of fire) middle level interconnects seem to have noticeable improvements in sound quality, while entry level interconnects seem to be pretty casing with mild sonic improvements. Just my honest opinion after dabbaling in low-end interconnects.
As aways I recommend trying a few for yourself.