REVIEW (in progress) - Nuforce HDP 24/96 USB-Optical 24/192 Coax DAC Preamp and Headphone Amp - Page 4

Exactly.

Yes, Sennheiser.

I never said it doesn't pair up well with HD600 ?!?!? I gave some positive comments initially and reported that the HDP sound signature fluctuates slightly with burn-in and that I don't want to post more impressions until the sound stabilizes. I don't have HD650 and don't like them as they are harder to pair with an amp than HD600, so maybe I should not speculate on the 650's right now.

Yes, I am. However the sound is fluctuating as the HDP burns in and I don't know where it will end up at 200-250 hours. I hit about 125 hours last night, halfway there.

The uDAC is not bad with the HF-2 and HD600, but is very underpowered with HE-5 and slightly underpowered with HD600. But, the uDAC does better with HD600 than many of my 5v portable amps do, and falls between those and my 9v amps. When using the uDAC, I actually like the synergy with HD600 on uDAC more than the HF-2 on uDAC, because the HF-2's strong bass and mids become even more prominent with the uDAC (RS-1 were better with uDAC than HF-2 as well).

So, the HF-2 and HD600 sound nice on the uDAC but they both make a noticeable gain moving to the HDP in detail, soundstage, transparency and power levels. The HDP clearly has more power than the uDAC (16v 42-45 watt PSU), and with full size phones like HE-5, HF-2 and HD600 the HDP sounds better.

REGULARLY SCHEDULED UPDATE 02/04/10, typed up last night after listening but forgot to post:

I am listening with some 24/96 hi-res albums that I downloaded from HDtracks.com (one example Nancy Bryan "Neon Angel") to listen to the HDP. I have between 120 and 130 hours on the HDP. Some of my listening is done by over-focusing on one area or aspect, and so I may not be familiar with all the differences between compared products. If I don't volunteer a piece of info then I wasn't ready to. Such are the failings of posting these snippets of impressions before I am done.

The HDP is opening up nicely with burn-in -> with better detail, depth and ambience/space than the uDAC, which is less detailed but warmer and more forward or intimate sounding. The uDAC when listened to by itself is very detailed, warm and euphonic sounding (pleasant), and the DAC is even more detailed and spacious via RCA out. However, the uDAC, when compared to the greater detail of the HDP, is almost like listening to a nice but lower cost tube amp that very slightly smoothes out the details and makes the sound a little more romantic and musical.

The uDAC is not embarrassed by the HDP, but it's performance is clearly not on the same level. It's in direct comparison with the HDP where you can best hear the slightly less treble presence and less detail and depth in the uDAC headphone out. The gap between the two lessens slightly when using RCA out into my eXStatA and Jade electrostatic rig, but it's definitely there - I am still only using the HDP in USB 24/96 with native 24/96 tracks and only half-way through burn-in. The HDP headphone out sounds crystal clear like my Apogee mini-DAC, while retaining a slight warm tint so it doesn't sound cold and sterile either. The Apogee headphone out may actually not portray quite as deep of a soundstage (Iron-Dreamer felt that way about the Apogee as well, before he sold it to me).

The HDP is also better at driving high impedance loads than uDAC -> if I match the HDP volume against the uDAC volume while using a low impedance Westone 2 or 3 IEM, and then switch to 300 ohm HD600 without touching the volume knob, the HDP is playing noticeably louder than the uDAC with the HD600. The sound signature of the Westone 2 IEM pairs up with the warmer UDAC a little better than with the HDP; but the Westone 3 and ES3X, UE 11Pro and JH 13Pro IEM all sound better with the HDP, as does the HD600, Grado HF-2 and head-direct HE-5.

In regards to volume after switching from Westone 2 to the HD600, in comparison the $450 24/96 USB CEntrance DACport review sample seems to fall in between the HDP and uDAC; and it is louder than the uDAC and quieter than the HDP when not touching the volume after the phone swap. But the detail and depth and ambience/space seems more similar to the HDP. The DACport is maybe very slightly more forward than HDP but not as forward as the uDAC. And the HDP maybe has slightly more treble energy than the DACport (which is still ahead of uDAC in treble presence). But otherwise they are similar in performance (not identical, but close, and I haven't had enough time with either of these DAC/amps to be accurately compare, so please don't ask for more till I am ready to volunteer it).

Unfortunately, the DACport only has one USB input and one 1/4" output for the same price as HDP with multiple inputs and outputs. DACport uses the headphone out as the pre-amp out if you want to drive an amp with it, but it is powered via the USB bus like the uDAC. I don't see see the DACport as a competitor to the HDP because it's geared for the portable laptop market like the uDAC, even though it's a 24/96 USB DAC like the HDP. DACport sounds as good as a $450 DAC/amp should sound (Apogee Duet 24/96 Firewire also comes to mind), but it lacks the additional features of the HDP or Duet.

Not a big fan of the K701, so somebody else will have to review it later with those.

No drivers are needed to use this with the Macbook Pro and OSX 10.5.8