Yulong D100

 
You probably have already seen my initial impression on the D100 if you read through the excellent review thread started by project86. It's been about a month now after I posted it, and I still enjoy listening to my D100 and love it even more now.
 
I use the D100 with my headphones, headphone amp and computer speakers, and the source is my laptop. The DAC section is very detailed and analytical sounding which I like because it shows you exactly what the recording is like. The AMP section is quite good as well. In fact, to my ears, the difference between the build-in amp and my Glimore Lite is subtle, at least on my K701s and HF2s. The background is absolutely silent. I couldn’t hear any background noise with my K701s and HF2s not even with my IEMs.
 
The line out is fixed, so the volume control only affects when using the build-in headphone amp. This is not a problem to me now since my computer speakers (AV40s) have a volume control. Although I do not plan to build a balanced rig using the D100, the XLR balanced outputs will still come in handy when I upgrade my speakers to some Bx5a monitors which have XLR inputs. However, in this case, it would be better if the D100 had preamp outputs since the volume control of the Bx5a is at the back. That being said, to solve this problem, you can simply add a pre-ampilfier between the D100 and your speakers/monitors.
 
Lastly, the USB input is actually quite good. I am not sure if it is because of the Asynchronous USB mode (versus Adaptive USB mode) or has anything to do with the ASRC process, but it is very close to the coax input.
 
To conclude, the D100 represents incredible value for less than $500 shipped. It is an excellent DAC with many input (AES, USB, Opt and Coax) and output (fixed line out and balanced out) options, and its build-in amp is not far behind too and offers a lot of value if you are looking for a dac/amp combo.
 
 
Thanks for reading and happy listening
 
 
 
Lee

Summary:
Read the pros and cons, otherwise: Very nice DAC with similar features to DAC1 + screen, power switch and HP mode switch. Possibly higher noise characteristics because of that.
Input jitter elimination possibly as good as DAC1.

In the box
Manual, power/usb cable - pretty standard.

Build:
No complaints for the case box, never opened the unit though.

Sound:
I thought Benchmark DAC was highs-centric and mids being somewhat recessed. D100 is mids centric to me. Good details on mids and highs, nice bass. A bit of a fake soundstage feel (if you heard K702 compared to other headphones, then you'll know what I mean). I think people often mistake treble amount for detail and resolution. Well, DAC1 was treble-focused(the treble was not rolled off enough for my liking and that give me the impression that the mids were not detailed enough and/or recessed) (see my review for it). Yulong D100 was close to just right for me. (both on line out and HP out).

Features
Lots of I/O, sound mode to potentially tame bright headphones (pity it does not extend to line out, some people would've found that useful)

USB does 96k/24b without drivers. Having had poor experience with Musiland's buggy custom drivers, this probably is a good idea. However, 96k/24b is not uncommon or particularly impressive nowadays. Still, the 'sweetspot argument' and ASRC to 110khz make this a moot point (see below)

The DAC1 manual talks about the jitter immunity thing and de-emphasis filter. Neither really seem to be unique to DAC1. Have a look at the datasheets below. Most DAC chips to de-emphasis. Now for the jitter immunity part: The Yulong D100 DAC section (well, the USB path) is nearly the same as DAC1 (pretty sure someone said it's the same as the m902 or Stello (can't remember,but can't be bothered googling at the moment - spent too long cooking). In any case, according to the DAC1 manual, it seems like most of the anti-jitter benefits on the DAC1 come from the USB->I2S->AD1896(mostly here actualy) ASRCto110k->AD1853.

So it looks like D100 will do well there too, since it goes USB->IS via TSA1020B->AD1896 ASRC to 110k->AD1955 (pretty similar to DAC1 there, except the newer AD1955, that seems to have marginally better THD+N, and SNR and a whole heap of circuits relating to things we don't need (DSD, etc))


I'm a bit confused about the 24b/192k stickers on both DAC1 and D100. I really thought that internally it'll all be ASCRed to 110k regardless of the input SR and input type. Even if your input is 192k via, say coax. The D100 review/benchmark do mention that is the case/110k max is for both the stability (AD1896, not AD1955 as the first page says as per http://www.benchmarkmedia.com/discuss/feedback/newsletter/2010/07/1/asynchronous-upsampling-110-khz ?) and DAC section performance sweet-spot being 96khz. I certainly believe them about the sweet spot being 96k

http://www.analog.com/static/imported-files/data_sheets/AD1955.pdf
http://www.analog.com/static/imported-files/data_sheets/AD1853.pdf

Presuming it's (fft 1k 0db for 48,96,192k sr) they (benchmark media) look to be correct.


So, provided my unit is not faulty with me finding it mids-centric and not neutral (compared to DAC1), it's a valid value for money alternative or side-step from DAC1. The only thing you probably won't feel: the hp amp is probably not a 0-feedback one. THD+N is probably higher on D100, (re: BnB opamps, screen, etc)

RECAP after about 6 mths of use

Well, I had several problems:
-the vol knob came off since it's made of cheap plastic and not a metal one held by a screw
-the unit died, possibly overheated, now all outputs have some sort of static, distortion and humming/buzzing.
-the unit refuses to accept input after I either connected or switched on an external amp (just says 'noinput' and doesn't accept the signal via usb).
-loud clicks in the HP when you switch the unit on/off.

In light of these (especially the breaking part), I've revised the review scores and lowered quality and design to 1.5 and 3 respectively. I hope Audiophile china and/or Mr YuLong help me out and fix it. (getting a replacement unit next week (21st Mar))

edit: got a replacement unit, took about a month. Probably won't be keeping it.

Skylab already linked to my review, so I'll just summarize here:
 
I find the Yulong amp to be very neutral and transparent sounding. I've owned various models in the $1,000+ range including Benchmark DAC1, Grace Design M902, and Lavry DA10. This Yulong competes well with those units and is even superior to some of them in certain aspects. The headphone amp, while not quite on the level of the DAC section, is still quite good, and you'd need to spend a significant amount of money on a standalone amp to get much improvement.
 
Bottom line: if you are in the market for a DAC on the level of Benchmark/Lavry/Grace, and are willing to sacrifice some brand name prestige, you can save a lot of money by going with the Yulong.

[size=11pt]Intro[/size]

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[size=11pt]I was approached by the Malaysian distributor of Yulong (the ShenZhen YuLong Electronics Co. Ltd of China) about reviewing the D100 DAC/headphone amp.  I had previously given a relatively favorable review to the older and less expensive/ambitious DAH1 Mk II, which was sent by their China Distributor, Audiophile China.  However, I gave a not-so-great review to a different product sent to me by AudiophileChina (not a Yulong product), and AC reacted badly, and so I suppose the fact that the request came from their Malaysian Distributor may not be a co-incidence 

  But these guys were very nice to deal with.[/size]

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[size=11pt]This product already received a VERY thorough, and very favorable, review from Project86: http://www.head-fi.org/forum/thread/499562/review-yulong-d100-dac-amp-reference-quality-with-a-reasonable-price[/size]

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[size=11pt]In spite of the fact that there is no chance that I can top that excellent review, I had already received my loaner, so I thought I would give it a whack anyway.[/size]

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[size=11pt]Description[/size]
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[size=11pt]The following are the technical details of the D100:[/size]

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1. [size=11pt][size=11pt]SNR: >120dB.[/size][/size]

2. [size=11pt][size=11pt]Dynamic Range: 115dB.[/size][/size]

3. [size=11pt][size=11pt]THD+N: <0.0005% at 1KHZ[/size][/size]

4. [size=11pt][size=11pt]Jitter reduction by using ASRC, custom made 1ppm high precision crystal oscillator[/size][/size]

5. [size=11pt][size=11pt]Using TAS1020B USB controller from Ti in adaptive mode. I2S signal then passed to ASRC and then to AD1955 DAC chip. Same THD+N <0.0005% is achieved via USB input, as compared to coaxial, toslink or AES/EBU input.[/size][/size]

6. [size=11pt][size=11pt]110/120V or 220/240 selectable operating voltage. [/size][/size]

7. [size=11pt][size=11pt]Inputs: Optical, Coaxial, USB, AES/EBU Balanced[/size][/size]

8. [size=11pt][size=11pt]Input digital signal format: 32-192 KHz, 16/24 Bit auto detection. USB input supports up to 24Bit 96KHz[/size][/size]

9. [size=11pt][size=11pt]Frequency response: 20-20KHz-0.16dB.[/size][/size]

10. [size=11pt][size=11pt]Power consumption: <20W.[/size][/size]

11. [size=11pt][size=11pt]Headphone output power: 130mW at 300Ohm, and 900mW at 32Ohm (Measured with chassis connect to AC ground)[/size][/size]

12. [size=11pt][size=11pt]Headphone amplifier with selectable sound mode button on the front panel. According to the maker, the default style Mode 1 is “natural and dynamic”, while Mode 2 “will result in a smoother sound, which is suitable for bright headphones, or if you prefer more “dark and smooth” sound”.  In practice, however, I found the two to be VERY similar.[/size][/size]

13. [size=11pt][size=11pt]Two headphone outputs with different impedances: LOW and  HIGH[/size][/size]

14. [size=11pt][size=11pt]Dimensions: 250*180*50mm.[/size][/size]

15. [size=11pt][size=11pt]Net Weight: 1.5Kg[/size][/size]

16. [size=11pt][size=11pt]Packing Size: 300 * 300 * 100mm[/size][/size]

17. [size=11pt][size=11pt]Include in the packaging: This DAC, user manual, USB cable. Power cable[/size][/size]

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[size=11pt][size=11pt]Pics:[/size][/size]

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[size=11pt][size=11pt]Ergonomics and usage[/size][/size]

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[size=11pt][size=11pt]I used the D100 in several ways:[/size][/size]

• [size=11pt][size=11pt]As just a DAC, through my RSA Stealth preamp, with both headphones and my Dynaudio powered monitors:[/size][/size]

• [size=11pt][size=11pt]via the optical input (connected to a Denon CD player for transport)[/size][/size]

• [size=11pt][size=11pt]via the COAX input driven from the coax output of the NuForce uDAC (used just for USB>coax conversion, about which, more later) being fed by my iPad[/size][/size]

• [size=11pt][size=11pt]via USB from my laptop[/size][/size]

• [size=11pt][size=11pt]As a DAC headphone-amp combo.[/size][/size]

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[size=11pt][size=11pt]The D100 had no problem playing music from the USB output of my PC.  Unfortunately, it would not work directly from the iPad’s USB accessory, although the Music Hall DAC 25.2 (which I used for comparison) did indeed work this way.  No issue with the coax or optical inputs whatsoever.  It’s nice to have so many inputs. [/size][/size]

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[size=11pt][size=11pt]The front panel display shows the input, and also the sample rate, which is nice.  When synced to a source, the sample rate flickers – which may be a “feature”, but I found it annoying.  But the DAC worked without any problems.[/size][/size]

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[size=11pt][size=11pt]Sound[/size][/size]

 

[size=11pt][size=11pt]The good news is that the D100, as a DAC, provides excellent sound.  From the RCA/Single-ended outputs, it was detailed, nuanced, and robust sounding.  I found the sound to be quite neutral, but not at all bright, fatiguing, or dry.  It was also very transparent.  Small details in the music were easy to pick out, but I never felt like they were being forced at me.  The sound was unfailingly smooth and natural.[/size][/size]

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[size=11pt][size=11pt]Bass was full, weighty, punchy, tight, and deep.  The mids were very clear and clear.  There is no added warmth here – if you want that from your DAC, this isn’t where to get it, although IMHO you should NOT ask your source to warm up the rest of your system.  Sources should be as neutral as possible, IMO, and the D100 is right on in that regard.  The treble is cut from the same cloth – neither dry nor overly sweet – right down the center.  Nice.[/size][/size]

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[size=11pt][size=11pt]“The Boy Who Wouldn’t Hoe Corn” from Alison Krauss and Union Station’s “New Favorite” was absolutely natural sounding via the D100 – impressively so.  I ended up using this track to A/B against the Music Hall Dac 25.2, which sells for about the same price as the Yulong, and has the same feature set.  The Yulong was definitely the better DAC.  It was more transparent, and more natural sounding.  The Dac 25.2 sounded grainy in comparison, and seemed to droop at the frequency extremes versus the D100.[/size][/size]

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[size=11pt][size=11pt]The D100’s headphone amp section is actually pretty good – also notably better than the Music Hall’s.  It’s nice to have a High-Z and a low-Z output, and I found the D100 was capable of driving all of my big headphones pretty well.  Compared to the Meier Concerto, though, the D100 lacked some nuance, delicacy, and soundstage definition and air.  But for the price, the D100’s headphone amp is quite good, and for anyone interested in an all-in-one, the D100 beats the Music Hall 25.2 for sure in that regard.[/size][/size]

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[size=11pt][size=11pt]Conclusions[/size][/size]

 

[size=11pt][size=11pt]I could go on and on, I guess, but why.  The D100 is a high-resolution, transparent, neutral, very well built DAC, with lots of inputs, SE and balanced outputs, and a pretty good headphone amp capable of driving a wide variety of headphones, for $500.  That’s a pretty seriously good deal for what you get.  It beat its direct competition handily.  In fact, it was so good, I sold the Music Hall, and I bought the review unit of the D100.  It’s a nice upgrade.  Maybe you, too, need a DAC upgrade?  If so, I’d seriously consider the Yulong. [/size][/size]