REVIEW (in progress) - Nuforce HDP 24/96 USB-Optical 24/192 Coax DAC Preamp and Headphone Amp - Page 26

Jason, are you referring to me? It sure seems that way, as I wrote this post last week:

Is the Nuforce Icon HDP really that good, then? I'm definitely interested, if that's the case!

If you will do your listening where the use of open style headphones won't bother anyone else then I'd mostly agree with Larry re: Senn 600s/650s though I personally like the HD650s a tad more than my old 600s. But I also really, really love the K702s a ton once you get 300-400 hours on them. But if you will be doing your listening, at least part of the time around others you don't want to disturb, Then I really love the Shure SRH840s a ton. It is one of the all around best buys in headphones today 'cause you can get them use for under $200 & just over that new. There are some other really good closed in headphones in your price range too, but I think the 840s are an exceptional value & are great with portable gear around the house too w/wo an amp. Most others we've mentioned require a good amp when used with an ipod or other MP3 player to sound their best. Someone above mentioned using Grado 325is with their new HDP but though it is one of my favorite headphones, I haven't found it to be a great match, to my ears, with the HDP. It can get "shouty" on some music with any amp but especially so with my HDP. I much prefer it with my tube or portable amps. I'm sure there is some way to tame them to an extent with your PC, but I haven't tried that yet.

Good luck & let us know what you decide. You really can't go wrong with any of the models mentioned - it just becomes a matter of personal preference - as always.

Jason, OK, I spent the day running the HDP with my various stereo gear & I was quite happy with the result. I ran it being fed by my Marantz sacd player to my Krell amps and to both my Kliphorns, & then my Omegas, & Heresy II's. While it did a great job, with the Krells to the Kliphorns, the soundstage shrunk both in width & depth, but it did sound a little warmer & a little less sterile compared to my Benchmark DAC1 HDR. It would be easy to listen to for hours. But when I put the HDR back in the mix, playing sacds or hd-dvds, I could see what I was missing.

Now using it with my Nuforce modded Oppo Blueray DVD player feeding my Dared tube amps to my Klipsch FR7s & later my Hornhoppe Horns, I thought it did a great job. I'd never used the DAC1 with that setup & I admit I didn't notice a huge amount of difference. All the details were there & it did great. I need to play with cables a bit more & I've called my friend who I'd sold my old Benchmark USB dat1 to & he's agreed to let me bring the HDP over and compare it with his gear. He has Maggie 1.6s being driven by Jason's Nuforce 9 mono blocks (about as good as it gets huh Jason). I don't remember what his source is now, he had a Wadia CD player when I sold him the DAC1 USB.
That DAC1 is pretty stock & is used primarily with his Mac. The Wadia's dac, really didn't need the benchmark's help. I may take the Oppo with me to keep things reasonable. The real target though will be the Mac with headphones, rather than speakers given his other gear.

Still, with what I've done so far, I'd say the HDP did better than expected. Given that you said it was the same dac that you used in your high end cd player, I guess I shouldn't be surprised. But with my primary set up, I'd have to say my DAC1 was clearly superior & besides I missed the remote! & the ability to run multiple sources including balanced. But the fact that it is even a discussion, given the huge price difference, says a lot about your HDP. As Larry mentioned earlier, I tend to leave it on all the time & not even bother warming up my tube amps. That never ever happened before. I've always favored tubes with any of my headphones but now I find myself not bothering. I just pick a headphone and get to work & listen to tunes. I'm happy!

Well, I've been fiddling with my new HDP for about 5 hours straight now and still find myself glued to the chair! Here's my initial thoughts so far (take it with a grain of salt for now, as it's still very early) through my netbook -> Foobar2000 (Asio4all):

- Very neat and tidy little box it came in. You can tell a lot of care went into making this presentable. The HDP itself is very solidly built and does look like one fine piece of audio hardware despite its small size and black appearance. The power supply looks solid as is the USB cord included (though I need one longer for my use so I'll be getting a new one shortly). My favourite accessory though is the included 1/4 adaptor, which is very sturdy and well built. I'll be using it with my ESW10JPN a lot.

- I first started off the first few hours using it as a standalone amp out of my netbook. Now, I'm not sure whether I've become entirely tube amp guy or whatnot here, but the results to me was a mixed bag; it went well with certain headphones, but not as well with others IMO. First, it DOES have plenty of power for every single one of my headphones and drive them all effortlessly so that's not the problem, and the detail retrieval and instrument separation is fantastic. However, it has a specific signature IMO that not everyone may like. I find the general signature on the cold side compared to my previous Pico -> WA6 setup. I also find the soundstage somewhat on a subpar side... this I was a bit surprised about as I expected better. Anyways, here's the brief summary of it as a standalone amp with headphones I tried:

* HD650: Great synergy IMO. Brings the details, speed, and dynamic out of the HD650 very well. Bass was well controlled, and mids were great and not veiled as it can with some of the lesser amps. Felt as if I could use more soundstage, but otherwise was very happy with this combo.

* K701: IMO, not that great of a synergy. This combo to me sounded extremely cold and plasticky. Synergy wise I felt that even the simple uDAC -> K701 sounded better than what it did here, but perhaps for people who strictly crave for detail and accuracy, it'll still be good to them as they indeed still do those things extremely well.

* RS1 (Flats): Did well here as the signature of RS1 with flats is warm in general. Brought the details out well and tighted the bass very well. Was actually better here than the old Pico -> WA6 combo.

* ESW10JPN: Pretty good overall IMO, but at times with certain songs sounded a bit analytic and bass light. But detail and clarity were amazing on this combo. More than adequate in all. I do hear VERY miniscule amount of hiss, which becomes a non factor when music is turned on, and is more about me being picky and anal more than anything.

* K271: See K701. Did not like AT ALL. Sounded even more clinical than the K701 combo and I would not use this combo for music personally. May do very well for monitoring/mixing purposes though however.

So overall, I felt the amp section was more than adequate but I have to say I expected a bit more out of it. Felt that it was more or less even in ability with the old Head-Direct EF1 amp that I had, which obviously is a decent amp. However, compared to the old Pico -> WA6, it felt like an obvious downgrade for sure.

- On to the DAC section, where it gets a lot more interesting... well, I'll start off by saying that I'll be selling my Pico DAC without hesitation. IMO, the HDP as a DAC beats it in every single way and addresses most of the problems that Pico had.

- I always felt that the Pico DAC didn't do the mids as balanced as I liked, and could always hear bit of an upper mid peak compared to slightly thinner lower midrange with any of the former setups I had with it. HDP IMO has perfectly balanced and organic sounding mids when hooked up to the WA6 (stock, with Sophia/RCA 6DE7) and get them just as I like them.

- I also felt that Pico had ever so slight bit of midbass boost, and in comparison the HDP sound more balanced in the bass area. It's never overbloated yet never sound overly thin or tight either.

- Highs are well extended and well defined, defintely more than Pico DAC, while never being sibilant.

- Detail retrieval and separation of HDP puts Pico DAC to shame IMO, to be blunt. To recite a common saying around here, "I'm hearing things that I never heard before in a recording".

- Soundstage honestly isn't MUCH of an upgrade over the Pico DAC, but it's at least on even terms with wideness and has bit more of a 3D presentation, with better positioning.

- I'll cut short with the headphone impressions for now, and will just say that EVERY SINGLE one of my headphones sounded better through the HDP -> WA6 combo than the Pico -> WA6 combo or HDP alone. Most notable performer IMO though is the HD650, which improved the most from the previous setup... I can honestly say that I now feel that HD650 is at its max potential with this setup.


So there is my initial impressions. To summarize again, I felt that while the amp portion did honestly disappoint me a little bit (but still more than capable enough), the ability of the DAC portion more than makes up for it. Perhaps about 7/10 for the amp portion (as good as my old EF1) but 10/10 for the DAC portion (did not disappoint my expectation of it significantly bettering the Pico) Overall, as a combo, I feel that I've spent my money VERY well. Hell, even if this was just a DAC, I'd still feel that it was worth the money! Top Class product.

Thank you for the review. I note I use both the HD650 and AKG701 phones; mixed results with that pair, from your review.

Funny, what you said about the sound signature and the ESW10JPN synergy seems to be the same complaint I have with my plain Icon's headphone jack too, but maybe it's just a coincidence.

One setup I'm considering is a HDP + tube amp (like a La Figaro 332 or Little Dot) for a different sound, but I'm also tempted by a used Stello HP100 and a good Chinese (as in A Chinese brand) DAC which would cost the same as a HDP. On the other hand, a simpler HDP combo would be more useful should I get seconded to London for a month or do a one year LLM in the US, or go into consulting and do one-site work. Who knows?

You're welcome. As I said, do take that 5 hr impression with grain of salt and keep an eye out for additional reviews as well. I wholeheartedly love them with HD650, but with K701 it's just not my cup of tea in terms of synergy. The amount of detail, separation and high end extension they give on both is very impressive, though. Perhaps when that separate power supply is out I'll take a plunge and see if that improves the amp performance at all (hopefully for soundstaging and more dynamics)


With the ESW10JPN, once I add the WA6 to the mix I feel that it gives it enough additional warmth and bass it make it sound exactly as I want it. Admittingly I'm not a fan of a sound that is too analytical, overly tight, and snappy (and both K701 and ESW10JPN does tread that line very finely with a lot of combos I've tried) so do keep that in mind. Of course, ESW10JPN was never meant to be overly bassy or anything so to expect too much bass out of it would be another thing.

As a DAC, I honestly cannot envision much of an improvement on what I am getting currently except for possibly better soundstage... but as I haven't tried many high end DACs I probably shouldn't speculate too much there.

Good review K19. I agree totally with you regarding AKGs 701/702 sounding better on tube amps. I think they need the mellowness of tubes to really sing- that and a lot of power!

The Senn. HD650s, to my mind, sound great with good ss amps & is at it's best with this little HDP so I feel you're right on in that assessment. But then I like my 650s with tubes too. If I just had to sell all but one of my headphones, I'm pretty sure the newer 650 would be the last phone standing. It isn't always my favorite headphone with each amp or each type of music, but it is always close to the top on almost everything. Very flexible!. I guess that's why professional reviews still call it the "gold standard" against which other phones are measured & most high end headphone cables are voiced for the 600/650s before anything else. That isn't an accident.

I hope you'll report your thoughts again after you have 100 or so hours on your HDP. I want to see if your review remains as mixed on your HDP then as it is now.

Yup, I agree that HD650 is best suited to tubes. The HDP -> WA6 combo honestly make them sing like I've never heard them before, and really give me the feeling I'm finally pushing them all the way to everything they're capable of. IMO the hardest thing to bring out of HD650 is the fine details and the highs extension and this setup has managed to do that without sounding too harsh. The slight tube flavour that WA6 gives (it's not the most tubiest sounding tube amp IMO) combined with detailing of HDP just makes it magical.

As for burn in, I actually bought it as a demo unit and the salesperson told me that it was already burned in (it was out there on the floor for 10 days; not sure it's been used constantly during that time). Not sure how much hours it has on board so far but hopefully I do see more changes. I won't expect anything dramatic but hopefully I'll least hear some improvement in soundstage and openness, which is one of my main gripes with the amp portion.

Thanks Larry. On HDP as an amp; perhaps I'm not being overly fair here as my ears are probably too used to the Pico -> WA6 sound which is more warm and tubey compared to HDP obviously. It's definitely been a while since I used a clinical, colder sounding amp of any kind so I do think I'll need to spend more time with it to adjust. I did want a different kind of sounding amp to the WA6 for this so in that sense it gets the job done very well while still having plenty of power for everything. In any case I did buy this unit as an upgrade in DAC first and an amp second, so I couldn't be any happier in getting the money's worth.

Yeah, I don't think any more update in DAC from here on will be happening for me, as I'm already more or less at my spending limit and I strictly just use my computer as a source through USB (and perhaps optical later). Plus I think I'd probably need to dip into the T1/HD800 levels in headphones before I can justify more improvement in my components. Perhaps that will happen one day, but I'll need to move on to job better paying before I can do that

BTW, just curious, at what volume level is everyone matching their HDP when used as a DAC? I know in theory the volume should be 100% but I've found that at about 3'o clock (with the unit sitting vertically), it matches the line volume output of the Pico and sound about the best at that level in general.

HeadphoneAddict, what's the synergy with your LA7000s like? I'm going to be in Japan next week and as I downgraded my whole rig to uDAC and NE-7m, I'm thinking of getting a pair of D5000s. I'm also interested in HDP, as I simply don't have neither place, nor money for a bigger rig. Do you think it would be a nice setup?

K19, I'm not sure everyone's volume control is mounted the same so where is your's setting when the unit is off? Mine is at about 6.30 when off & about 5:30 when at 100%. So far, when using it as a dac to drive my Doge or LDV, I'd just set it at 100%. I'd planned at some point to play around with different settings, especially when trying my IEMs (something still on my to-do list) but haven't yet. I take it your 3 o'clock setting isn't full on? Are you finding you get better sound at less than 100%?

Larry, I too at one point came very close to selling my 702s because they just weren't giving me the sound I'd gotten from my 701a. But then I remembered my 701a had had a Stephen ArtAudio cable modded on it & over 500 hours on it by the time I'd gotten it so I bought the SSA upgraded cable, put another 200 hours on both, & now on my tube amps, with the right music, especially classical pieces - IT JUST DOESN'T GET ANY BETTER. Especially on complex pieces, it just opens up the sound stage like no other phones I've ever tried & I hear things I'd ust never noticed on my HD650s. Is it a little base shy, yeah it can be, esp. compared to the HD650s listening to the same piece, but now I find the base is still there & I often find it a little cleaner & tighter rather than "base shy". I have about 500+/- hours on these & I swear they are still changing. My neighbor, the recording engineer, says he exclusively uses K702s & the Benchmark DAC1 to do his recording sessions claiming that the combo provides the most uncolored honest sound me can get. But he said at home, he primarily uses his HD600s/650s & Grado PS1000s for his listening pleasure he's said. But as with everyone, it is personal taste otherwise we'd all be using just one headphone &/or one IEM.

Don't be ridiculous . You have 5 hours of breakin and you are making the impression already? The headphone amp circuit path would take > 100 hours of breakin (unlike the DAC). Even if you don't have that kind of patient, at least let it breakin for 50 hours.

You may have missed my earlier post saying that this is actually a demo unit I purchased from MacGroup which has apparently been fully burned-in while it was out on the floor (well, at least according to the salesmen).

Initially I matched it with the volume levels of the Pico DAC line out (which is the 3 'o clock setting I mentioned earlier) so that I can set up the WA6 at similar volumes that I did with the Pico. The volume range on the volume control seems about the same as your range. 3 o'clock on this is not max but about I'm guessing 80-85%... I did try them on full volume with WA6 volume toned down a little instead, and what I felt with all my headphones was that they made things more detailed and clinical but in taking away bit of the warmness. Worked well enough for something like HD650 and RS1/flats but definitely not K701/ESW10JPN. I felt that it took away bit of the tube sound that WA6 outputs by setting it up that way, but I'll definitely need to experiment with that further as it could be just my mind playing with me. Or perhaps my ears haven't adjusted to all the detailing the max setting gives Definitely no distortion or clipping of any kind at max DAC output volume, though.