NuForce Icon uDAC Review
Introduction :
The NuForce uDAC took the head-fi world by surprise when it was launched and set a benchmark for entry level digital to analog converters .I was really excited to get my hands on what people called one of the best budget DAC. Soon enough I was able to try out a fellow member and friend's uDAC and I really couldn't believe what I was hearing. But having heard it for a very short time period I wasn't able to perform extensive testing, comparisons or draw any concrete conclusions. All I knew back then was it sounded good. A few weeks back I received a sample of the uDAC for testing and finally was able to make out what the uDAC is all about .
I wouldn't be getting into the basic concepts, pros/cons of a DAC against soundcards etc because it has already been discussed on TE and I expect the reader to have a fair bit of idea about the same .So lets get down to the review of the NuForce uDAC .
uDac Features :
• Discrete USB audio receiver, D/A converter and headphone amp
• Coaxial S/PDIF output (turn off volume control to activate)
• Double jitter-reduction mechanism at data level and at oversampling filter stage
• High voltage 2V analog output
• High-quality analog volume control
Specifications :
Input
- USB (USB 1.1, 2.0 compatible)
- USB DAC: USB 1.1, 2.0 compatible. USB native bit rate: 32-48kHz, 16-bit
- Maximum sampling rate: 48kHz
- Resolution: 16-bits
Output
- Analog RCA Output = 2Vrms
- Dynamic Range: 110dB
- THD+N= -95 dB
- S/N Ratio: 98dB
- Digital Output: coaxial RCA 75-ohm
- Headphone output jack
- Power output: 80mW x 2 @
- 16-Ohm
- THD+N 0.05%
Power
- USB powered
Dimensions
- 68 x 38 x 21 (mm)
Packaging and Design : [FONT="]
The uDAC comes in a small transparent blister pack. In the front you have the NuForce icon uDAC labeling in purple .The purple theme is extended on both sides of the box with the NuForce label. Once you break the seal and open up the box, there's a plastic tray holding the uDAC in place along with the USB cable and a manual . There are no other accessories supplied with the package; anyway, one wouldn't need anything more than the provided USB cable to connect the uDAC to their PC. To use the RCA line out & digital output , one will need to use their own respective cables .
The first thing that will surprise you about the uDAC is how small and lightweight it is .Its about the size of two small matchboxes placed next to each other and pretty small compared to most other DACs in the market. This would be most appreciated by regular travelers who plan to use it with their netbooks,laptops etc. The complete housing is put together by three parts of anodized aluminum which is very well crafted and has a solid feel to it. The centre unit has the NuForce engraving on top as well as bottom whereas the front part which is put together by 4 visible screws has the volume control pot ,a power on blue LED(turns on when it received power from USB) and a standard 3.5 mm headphone out which gives the amplified DAC output to drive headphones/earphones. The backplate again is joint to the main body by 6 screws and has the USB input, RCA line out and a coaxial digital output. The coaxial digital input doesn't process the sound through the DAC but just acts as a USB to coaxial converter, if one wishes to play music via another DAC which doesn't accept USB input.
At the heart of the uDAC is a ESS9022 Sabre DAC chip which is pretty new but very well received in the audiophile community. Anyway, along with the DAC chip there are a lot of other factors like components used in the circuitry, power supply, amplifier section which account for the sound quality . I did open up the uDAC to have a look at the insides but couldn't make out much as the two boards are sandwiched together upside down. From whatever I have had a glimpse of , the soldering work looks neat.
The built quality of the uDAC is pretty impressive and solid. You can feel the quality when you hold the small device in your hand .Couldn't notice any loose ends or compromise on the quality .The volume control pot is smooth and fixed firmly , even the RCA and coaxial ports are gold plated.
The only change I would prefer would be step wise increment of the volume control pot ,rest all looks perfect and I am glad to say that it does not feel like one of those cheaper chinese products when you hold it in your hand. The finish and built is top-notch.
[FONT="]
[/FONT][FONT="]
[/FONT][FONT="]
[/FONT][FONT="]
[/FONT]Performance.
Testing procedure :
The testing was carried out over a period of 2-3 weeks, most of which was spent comparing the uDAC side by side with my other sources like Asus Xonar DX soundcard and the HiFiMan EF2A DAC + Hybrid tube amp. Different headphones /IEMs were used at the output end to understand the synergy of the DACs with different sound signatures.
Tracks used :
Used my usual FLAC / 320 kbps collection of electronica/trance ,Some classic bollywood movie tracks, Metallica,Kailash Kher ,A.R Rahman collection and Alanis Morissette- unplugged along with some good quality live recordings to test the soundstage.
My Impressions :
I connected my modded Altec Lansing MX5021 to the Xonar DX and the uDAC via the RCA line out to aux in of 5021 .I am not sure if this is a pure line-out signal of the DAC as the volume control pot works as normal (with lower volume compared to headphone out) which usually isn't the case with a line out signal which is at a fixed volume. Ive mailed NuForce for more details for the same and will update the thread once I hear from them.
I compared the sound switching back and forth between the uDAC and Xonar DX and the first thing I noticed was that the soundstage with uDAC was much wider than the Xonar DX and the overall sound was slightly more clear/noiseless compared to the Xonar DX. Other than that there was a slight improvement in the detailing as well but not an enormous difference. Just the bass sounds more textured and has more depth to it .Midrange and treble extension was on par , couldn't notice any major difference .Overall I prefer the uDAC for the wider soundstage.If not for the soundstage ,both are almost on-par when connected to speakers like 5021s.The difference in midrange and treble is so subtle, one really needs to give a critical ear to notice it.
Later I hooked up the Denon AH-2000 headphones to the Xonar DX and HiFiMan EF2A DAC + hybrid amp .Do keep in mind though the D2000s are in mid-fi /hi-fi territory they are lot easier to drive than the Sennheisers or AKGs but it does need a little juice, not for the volume, but for the detailing to show up.
The Xonar DX drives them to satisfactory levels. However when you switch to the uDACs headphone out you realise that you've been missing quite a lot .First of all the the bass has much more impact and authority on the uDAC and the sub-bass is more prominent compared to DX. The D2000 has such contrasting sound with the peak in its bass and treble detailing that it's midrange sounds a little recessed. The uDAC does a good job of bringing out the mids and this shows that the headphone out of uDAC has a warm sound. It has a smooth forward sounding midrange and a slightly more bass quantity . The treble detailing is amazing and miles ahead of the Xonar DX in comparison.It's very clear and has a nice sparkle to it .Its a little bright compared to the DX and It gets sibilant at times as the D2000 itself inherits some sibilance. Cutting down the 10K band in Foobar EQ attenuates the sharpness in sound.
Between the DX and uDAC , the uDAC is a clear winner when it comes to driving even the less demanding headphones.
Comparing the EF2As DAC + headphone out(CV4010 Mullard tubes) to that of uDACs the EF2A has a pretty good detailing but the overall sound signature is slightly dry and cold.The uDAC sounds nice and warm whereas the the EF2A has a dark sound. Also the EF2A can't reproduce the low end bass frequencies like the uDAC and its noticeable when you don’t hear the deep impact and slight reverbs in the bass which is there in the uDAC.Overall the uDAC again has a slight edge over the EF2A in sound quality but this is mainly due to the not so great DAC on the EF2A.Otherwise the EF2A has a lot of potential which you will come across later in the review.
After the D2000 , I picked up one of all time favourite IEMs , the Head-Direct RE-0 to try it with the uDAC. The RE-0 has a very analytical and neutral sound signature. Light bass, dry midrange and an amazingly detailed treble extension. Yet it sounds blissful everytime you try it due to its top-notch transparency and unmatched detailing .It's just a little too neutral to enjoy your music but best for testing other gears or critical listening. Now here comes the best part , the synergy of uDAC and RE-0 is a match made in heaven. The uDAC at a ~40% volume has enough power to drive the RE-0s to their best. The light bass is boosted up by 2-3 levels. But its just the quantity of bass that increases. The quality still isn't as good as RE-252 and the very low end of spectrum is missing in the RE-0.Doesn't really matter because the midrange and treble sounds so perfect. A slight warmth is added to the dull midrange of RE-0 and the existing treble sounds even more enhanced.
The sound is exactly what Ive been looking for from an RE-0.It makes it musical without losing the detailing and retaining most of its neutral sound signature. Just adds up to the missing bits. Now I wish if the uDAC was a portable amp as well . NuForce must come up with a uDAC mobile , I am sure it would sell like hot cakes if priced right.
Finally I tried the HiFiMan RE-252 with the uDAC. The synergy isn't the best as the RE-0 probably because the 252 already has a slightly warm midrange. It sounds better than my portable gear ofcourse but with the uDAC , the 252 loses its neutral sound and the midrange sounds more forward. The soundstage is much better compared to Fuze which I usually use with 252 on the move. The 252 on the other hand sounds much better with the dark sounding EF2A amp .I prefer it over the uDAC . Its not about detailing but more about the sound signature.
Other than these 3 headphones which I used for extensive testing of uDAC ,I also tried the uDAC with Tiwari's Audio Technica AD700 and found substantial increase in soundstage as well as detailing .Similarly almost all my other low-end IEMs like Brainwavz M2,NuForce NE7 show improvements in terms of authority of bass,soundstage etc when paired with uDAC.
Just for the sake of it I even tried a slightly different combo of uDAC as the DAC + EF2A as amp connected via line out of uDAC. Needless to say the sound was amazing .The fullness and wide soundstage of uDAC was there and the cleaner and darker sound of EF2A sounded more like neutral with the warm uDAC.
Here's what I would prefer personally - uDAC + EF2A > uDAC >> EF2A \Xonar DX .
> - slightly better, >> lot better
[FONT="]
[/FONT]Rating ?
How about a 4.2/5. I really can't find any flaw in the product and it actually loses points just for the lack of neutrality. Not that I complain but lot of people might. Lot of best DACs/amps out there do not have the most neutral sound. Also the warm sound signature is basically due to the headphone amp, the line out pretty much sounds neutral (as read in MX5021 impressions).
Final Thoughts :
If you could manage to sit through the long and boring sound impressions you would've realised by now that the uDAC doesn't really have the most neutral sounding headphone out .It has a very good speed and decay in bass attack and a slight boost in the sub bass which gives the bass a good impact. I wouldn’t call it boomy or heavy bass but perfect bass with good authority. The midrange is slightly warm and forward sounding .The treble is very slightly coloured, although extremely detailed .This is the part which gives most of the first time listeners an impression that the uDAC is the best sounding DAC ever. The slight colouration in sound makes you feel that the uDAC belongs to a much higher level. Its very musical and really helps you immerse in the sound , I am saying this because I don't enjoy my D2000 with any other source as much as uDAC.
Conclusion :
Having said so much about the sound with diverse gear what I feel is that the uDAC will have good synergy and sound brilliant with anything that has a dark,cold or neutral sound signature. It will be pretty good with anything that has a hint of warmth but if the headphones are already too forward sounding or already have a smooth liquid midrange sound ,it might not sound the best. For anyone moving from an onboard or a low end soundcard , the NuForce uDAC will surely make you go wow everytime you try it , provided you have something respectable connected at the ouput.
On the whole uDAC is an amazing value for money product built with budding audiophiles in mind and could very well be an inspiration for beginners and audio enthusiasts waiting to discover the sound of some hi-end gear. I would rate it 4.5/5 for the overall value for money performance, portability and solid built.
Who should buy it ?
Anyone looking for a good VFM source for their speakers and mid-fi headphones. The uDAC will effortlessly drive most midfi cans like Audio Technica AD700s,M50,Shure SRH840,Sennheiser HD555,Denon AH-D2000 and the likes to their peak performance. It might drive some more high end cans like HD650 etc but struggle in reproducing their full potential. Anyway, someone investing in an HD650 or AKG 702 is expected to invest in a much better desktop DAC +amp.
Frequent traveler’s who would want a very small audiophile quality source to listen to the music on their laptop/netbook.We all know how good most onboard sound cards are .
Who should not buy it ?
Anyone who plans to invest in a 5.1 headphones/speakers and thinks he can use/ replace the uDAC with the soundcard. I know this sounds quite weird, but I am mentioning it because Ive actually been approached by a few guys who want to connect 5.1 output to this. The uDAC is a pure stereo audio processor and is best suited for 2 channel headphone & speakers only.
Anyone who is very concerned about perfectly neutral sound .To most people the richness and warmth might sound better but quite a few would like it to be close to flat response.
