I've got stock D2000's and use an Audio-gd Fun, with the [size=x-small]AD1852[/size] DAC and Earth HDAM. I ordered the FUN just as the sparrow was announced, and also just as the lower cost Fun was announced. I've found the AD1852 a little too bright for my taste, and settled on running the fun with soft3 sound settings to tame it (soft 1 and 2 were not enough). Lots of run in on this amp, about 400 hours or so now, still too bright for me if the jumpers are pulled. The Wolfson DAC is perfect for my ears for the high frequencies, no need to run the sound settings, but its sort of muddy sounding, the ad1852 spoils your ear with clarity. A fun is not a sparrow I suppose, but they are certainly closely related. All in all, a good combo, but I'd caution you if you consider the D2000 overly bright or sibilant to start with.
RonO