I tried it all, the iFi iPurifier 3.0 actually made a difference but it still wasn't quite good enough. The thing is this DAC is either brutally transparent to the source material or it's introducing a bit of harshness. For me it made certain songs I usually enjoy somewhat unlistenable. Someone else mentioned the heavy attack, which for the layperson, is basically the snap in a drum sound, and it's very heavy with the Standard DAC, so much so that while it sounds very dimensional it's also very fatiguing. I just couldn't listen to it for more than a few minutes. I ended up going with the Musical Fidelity V90 instead, which is 3x the price but has a sweeter and more musical sound. Both DAC's are a little on the boring side, but at least I can listen to the V90. Anyway, rant over, not a bad product for $80 but it doesn't sound great in my system.
Would not recommend to a friend.