Is my DAC my weakest link?

@ryunosuke13 - What amp do you have? You say "Audionics BK-ST 140 (BT-2)". However, that doesn't seem to be correct. 

Audionics made a pre-amp model BT-2 and B&K made an amp model ST-140. I'm guessing your amp is a B&K ST-140, correct?

I second the suggestion to try Chord Mojo. Compared to old dacs it may already be staggeringly good. I have a Bricasti M1 SE but Chord is very very good indeed at a fraction of the price. 

Some manufacturers of high quality dacs such as Benchmark also allow in-home trial with free returns (minus shipping costs, which are moderate).

get a TEAC NT-505

+1 @erik_squires on the Furman recommendation for your system. A power conditioner basically does what it sounds like it does. It makes sure the power your system sees is, in easy terms, "clean and steady." The electricity coming into your house has audible noise in it and it doesn't always (or ever) come through the lines in a uniform, steady flow--electricity surges--and a power conditioner helps harness this attribute and provide your equipment with a steady diet of cleaner and steadier power. I've oversimplified but hopefully the explanation helps you. BTW there are many folks on this site who don't use any power conditioning because they do not think it adds significant value. I have run previous systems without power conditioning. However, I am now a strong proponent of using power conditioning. FWIW the Chord Mojo will probably provide you a more discernible audible improvement in your sound than an entry level Furman. But that doesn't mean the Furman isn't a good idea for you. 

There is nothing wrong with the AC power coming out of your outlets! Don't fall for all this "power conditioner" B.S. Same for interconnects! Use what you have and enjoy the music! There is NO benefit to raising speaker wire off the floor! Enjoy your system and don't become a neurotic and gullible audiophile!