Hi,
The main virtue of Harman's Digital Path receiver design (in the 1001, 2005, 1005) is the elimination of a large, heavy tranformer and the gain in efficiency and cool running of a digital switching power supply. There are also fewer analog-to-digital (A/D) and digital-to-analog (D/A) conversions of a signal passing through the processing and gain stages of the receiver, which in theory eliminates possible digital artifacts.
That's all well and good if you start with a digital signal from a CD player or DVD player, but if you plug in an analog source, the audio signal still goes through A/D conversion. And in the final output stage, the digital signal is converted to an analog form, which must occur because current speakers only handle analog input signals.
You're correct that total harmonic distortion figure specs (THD) are higher (0.15%) than H/K's conventional receivers, which specify THD at 0.07%. But 0.15% is still far below audibility with music signals and many orders of magnitude less than early solid-state amplifiers, which often had THD of 0.5% to 0.9%.
On the other hand, the audio bandwidth of H/K's DPR 1001 and the newer models (DPR 1005 and 2005) is limited to 20 kHz at the top end, compared to 130 kHz for H/Ks conventional receivers. If you believe human hearing extends beyond 20 kHz --- I do not, nor has it ever been scientifically proven or demonstrated -- then the DPR 1001 won't do it for you, whereas conventional H/K receivers will.
Noise figures are in the same region as conventional amplifiers and receivers (IHF-A) at -97 dB, which is far below audibility. I've not seen thorough bench tests of these new digital receivers to see if there are other liabilities that may emerge. Digital switching power supplies must be very well shielded against radiating ultra-high frequency RF garbage, but it seems that is now well controlled.
Regards,
