[slim.a]

 
Quote:

I've been listening for the DAC-19DSP & C-2 combo connected with ACSS and feeding AKG K601s a lot this weekend. I think I'm starting to understand this gear, so I thought I'd let you know my observations.

Let's start with the music used for the testing. I've been using Spotify Premium for months now. It provides a 320 kbps Ogg Vorbis stream and to me has all the sound quality I need. I've tested flac (through XBMC & WASAPI) every now and then, and did once again this weekend with the new gear. Even with this very revealing equipment, I couldn't tell the difference on most samples and with the ones I thought I did, I needed several back-and-forth cycles to make myself convinced. So one thing that is here to stay is Spotify Premium as my number one music source. Since I don't listen to the "audiophile" stuff that much, the convenience is well worth the minor or rather neglectable sacrifice in sound quality. Spotify is running on my PC, and I tried different connections between the PC and the DAC. Integrated toslink and integrated coax sounded the same to me, but there is an issue with my motherboard that distorts the sound from time to time using the integrated digital connections. I tried the USB of the DAC-19 and it sounded ok, but had an intermittent static noise problem that was enough to steer me away. I then tried the more complicated route of using the HDMI connection of my graphics card to my TV and then forwarding the signal from the TV's optical out to the optical in of the DAC-19. Worked ok, but had me suspicious of the damage done to the signal with all the different connections. So I did some A/B testing between it and the integrated coax (which, most of the time, worked flawlessly despite the distrortion issue) and simply could not tell them apart. To me, the DSP1 seems to be doing a great job with clening the signal up. This is the kind of robustness that I was looking for when choosing to go with the DSP version. Still, I'm considering HiFace as a transport, but there might be a more imminent purchase on the horizon (more of this at the end of the review).

So, what do I listen to? I don't like genres as a concept, so I'll just list some albums that have had the spin in the testing: Faith No More: King For a Day, Fool For a Lifetime ; Pain of Salvation: Scarsick ; Dream Theater: Awake ; Pantera: Vulgar Display of Power ; Slayer: Reign In Blood ; Nine Inch Nails: Fragile ; Opeth: Ghost Reveries ; Slash: s/t ; Blackfield: II ; Eagles: Long Road Out of Eden ; Dire Straits: Brothers in Arms : Billy Cobham: Spectrum ; Dave Holland: Critical Mass ; Sibelius: Finlandia ; Zero Hour: Grasshopper ; Clutch: Strange Cousins From The West. And a couple of dozen other great titles.

On to the sound. As I wrote earlier, this is most definitely not a warm sounding combo. I've had some doubt if it's even neutral because the upper mids and the treble are that bright. But since there's absolutely no harshness on good recordings, I think it's not a symptom of overly bright gear but a clear view to the errors on the recordings them selves. What is known as sibilance is in many cases something that has been captured on the recording and, as such, should be reproduced by neutral and detailed gear. In this case, it is and it's not always pretty. Euphoric sounding this combo is not, but even if there's a lot of the upper band, there is no spikiness that would force you to turn the volume down.

The chief and commander of this combo is the DAC-19, for sure. Using ACSS the C-2 is very much a "wire-with-gain" kind of an amp that simply gives you what the DAC feeds it. I gave the DAC a good listen with my speaker system, too (Marantz PM-15S1 => Tannoy DC6 T). The same characteristics are there: clear, detailed, dynamic. What was new was the VERY fine feel of space. Now, the soundstage is of course always different when moving from headphones to speakers, but the fact that I hadn't really paid any special attention to it with the C-2 + K601 suggests that I've somewhat hit the limit of the K601s' soundstage capabilities. The DAC-19 is capable of giving a far more involving soundstage than my phones. This combined with the slightly more-than-enough nature of the treble has set me of thinking new moves regarding my headphone repertoire... A very possible scenario is me getting HD 650s to complement my AKGs. I think that would give me a good enough set of different sound signatures.We'll see what happens.

In conclusion: DAC-19DSP & C-2 are great. The DAC has qualities that I've not heard before (clearly beats my ex-CDP, Marantz SA-15S1). The combo isn't a perfect match with my music taste and headphones, but even though I've been using AKG phones more or less exclusively for the last ten years, I now find myself questioning them. The virtues of the Audio-gd combo are enough to justify a purchase of a new pair of phones, it seems. You know the thing about my wallet, right? Oh, save it...!

Thanks for the impressions.

Concerning the revealing nature of the DAC19 DSP/C2, you are absolutely right. When the recording is poor the combo does nothing the hide the mistakes put at the same thing (which is rare at this level of resolving gear) it doesn't add any unpleasing distortion that is not in the recording. For example, the very expensive 3D Lab Master CD player I listened to last week had less details than the DAC19DSP and was more sibilant and harsh sounding with poor recordings. At the meantime, while the DAC19DSP is smoother sounding than many sigma delta DACs, it won't sugar coat your recordings like some tubed output DACs do.
As you have said it, the C2 is pretty much a "wire with gain" when used with the ACSS connection. Most of the time I just forget I have a headphone amp in my chain which is exactly what a headphone amp should do.
Therefore, when listening to the dac19dsp/c2 combo, you get a honest/neutral DAC and a "wire with gain" kind of amp. Even playing with different sources doesn't alter the tonality of the combination (the modified hiface brings mostly more details and better soundstaging in comparison with lesser sources). That leaves pretty much 2 factors that will impact the overall balance: The headphones and the power cords (to a lesser degree).
Overall, you get a pretty big variation in sound from one recording to another and a different listening perspective going from one headphone to the other. Some people buy dacs/amps to cancel the defficiencies of their headphones or tune the system to a particular "view"/perspective into listening to the music (always warm or always anlaytical or a big soundstage ...). This is not the case as the dac19dsp/c2 disappear (relatively speaking) to let you hear the true character of the associated headphones.
 
As for the sounstage, I don't know if the HD650 (with the stock cable) will be a big improvement over your akg601. When I listened a while back ago to the akg702 (with stock cable) on my previous set-up (dac19mk3/c2c), I felt that he imaging was less defined but the size of the soundstage was slightly bigger than the silver cabled HD650.
 
As for me, I am also looking for a new pair of headphones as I feel that the HD650 are also a limiting factor here. I might settle on an ALO recabled Beyer T1 but there are other headphones that are tempting me so I am holding on for now. In any case, the dac19dsp/c2 is a good enough platform that I have decided a no more electronic/cable "upgrade" until I get a new pair of cans

 

[pategen]

slim.a,
 
I agree, AKGs have a big sound stage. It's just that for the three-dimensionality that the DAC-19DSP is capable of, the great width actually turns against it. What I really find unique with my speakers is the depth and accuracy of the sound stage, and that is what's missing with the K601s. It's been a while since I last had a good listen to a pair of HD650s, but from memory I think it could give better depth and definition sound stage wise, and at least it would offer a more laid-back top end for the edgier recordings. Beyer's T1s are great, I'm sure, but according to measurements, the Teslas have a rather big spike in the lower treble. That's something I would be cautious with when pairing phones with this gear. As it turns out, HD800s have some spiking in treble, too, but to a lesser amount.
 
By the way, the top end seems to have settled down just a little bit since I wrote my review. I really thought the gear would have reached it's full potential with around 200 hours under its belt, but it hadn't. There wasn't a gradual change for the last part of improvement, but rather a one time step at around 230 hours of burn in. Interesting to see if that's finally it or if there's still more to come.

 

[Currawong]

A number of us found the transistors used in Audio-gd gear seem to take about 350 hours to settle.  

 

[kunalraiker]

what would be the the resolutions for input from usb to the DAC19

 

[FauDrei]

16 bits, 44,1 KHz and 48 KHz

 

[kunalraiker]

Quote:

16 bits, 44,1 KHz and 48 KHz

I was looking forward to hi-res,the only way now is using hi-face then.

 

[slim.a]

Quote:

slim.a,
 
I agree, AKGs have a big sound stage. It's just that for the three-dimensionality that the DAC-19DSP is capable of, the great width actually turns against it. What I really find unique with my speakers is the depth and accuracy of the sound stage, and that is what's missing with the K601s. It's been a while since I last had a good listen to a pair of HD650s, but from memory I think it could give better depth and definition sound stage wise, and at least it would offer a more laid-back top end for the edgier recordings. Beyer's T1s are great, I'm sure, but according to measurements, the Teslas have a rather big spike in the lower treble. That's something I would be cautious with when pairing phones with this gear. As it turns out, HD800s have some spiking in treble, too, but to a lesser amount.
 
By the way, the top end seems to have settled down just a little bit since I wrote my review. I really thought the gear would have reached it's full potential with around 200 hours under its belt, but it hadn't. There wasn't a gradual change for the last part of improvement, but rather a one time step at around 230 hours of burn in. Interesting to see if that's finally it or if there's still more to come.

I have just been reading on the K601, I didn't realize that they were that different from the K701. Given what you are looking for, which is better soundstage definition and a more laid back representation, there is indeed a high probability that the HD650 will suit your needs.
I will however strongly encourage you to upgrade the stock cable of the HD650. With a set-up such as the dac19dsp/c2 there is a pretty big difference. You can read my review of the Artisan Silver Dream cable here: http://new.head-fi.org/forum/thread/492395/review-mark-2-artisan-silver-dream-headphone-upgrade-cable-for-the-sennheiser-hd-650
Out of the 5 aftermarket cables I tried, the only one I would advice against trying is the StefanAudio Art Equinox. It is not that it doesn't improve the sound (it does) but it is not worth the asking price in comparison with the competition.
 
Concerning the T1, I have also been puzzled with the spike in the frequency curve. However, when I listened to it for a brief period when Pacha brought his T1 at my place, I was very impressed with what I heard. The other headphone that is tempting is the Audeze LCD2 but since no one has tried it with the C2 amp, I would be shooting in the unknown.
Anyway, I am pretty satisfied with my current dac19dsp/c2/silver cable/HD650. And I could live happily ever after with that combination if it weren't for that damned upgraditis bug
 
As for the burn-in, I also found out that it takes around 2 weeks/350 hours of run-in before the sound settles.
There is also another important factor. Even after full burn-in, I noticed that both components, and especially the DAC19, need a few hours of warm up time before they sound their best.

 

[slim.a]

Quote:

what would be the the resolutions for input from usb to the DAC19

 
Quote:

16 bits, 44,1 KHz and 48 KHz

Yes, the dac19 was limited to 16/48. However, the usb chip that was being used previously on the dac19 (the pcm27xx) has been discontinued according to Audio-gd.
They are going to replace it with something else so maybe they are going to finaly use something that is not limited to 16/48. Somebody should ask Kingwa about it (I ask him way too many questions so I will let somebody else do it

).

 

[pategen]

slim.a,
 
thanks for your input. I'll look into the cables if I decide to go down the HD650 road. I think I'll give the DAC and the amp the complete burn-in before I make my move. So far, I've put them on the first thing when I wake up and turn them off the last thing before going to bed, so they are well warmed up in the late afternoon / evening, when I do my listening. A few more days and I'll know for sure what I have got and what I'm still missing.

 

[SoupRKnowva]

hey slim.a, maybe this is a little off topic. but with how much money and effort you put into cables and others extras, why have you not gone ahead and gotten like a ref1/7 and a phoenix? and go for the best audio gd has the to offer.
 

 

[Pacha]

 
Quote:

 
Concerning the T1, I have also been puzzled with the spike in the frequency curve. However, when I listened to it for a brief period when Pacha brought his T1 at my place, I was very impressed with what I heard. The other headphone that is tempting is the Audeze LCD2 but since no one has tried it with the C2 amp, I would be shooting in the unknown.
Anyway, I am pretty satisfied with my current dac19dsp/c2/silver cable/HD650. And I could live happily ever after with that combination if it weren't for that damned upgraditis bug
 

 

 
 
The LCD-2 is slightly better sounding than the T1 according to Skylab, but there is need to compare it with recabled T1 which may be quite equally good. The real pain with the LCD-2 is its "torture" comfort with its 550g, Skylab even said the improvement in SQ is not worth the pain relative to the overweight issue IIRC.
Since I already found the 260g of your HD650 to be a pleasure wearing on the head in comparison to the 350g of my T1 which is not very heavy anyway, I can't imagine with the 550g of the LCD-2, must be terrible.

 

[slim.a]

Quote:

hey slim.a, maybe this is a little off topic. but with how much money and effort you put into cables and others extras, why have you not gone ahead and gotten like a ref1/7 and a phoenix? and go for the best audio gd has the to offer.
 

This a valid question. The reason I have taken my particular upgrade path instead of using the money for something higher up the ladder like ref1/phoenix is because I have a different upgrade philosohy than most headfiers.

According to my personal experience and to the research I have done on the subject, I believe that to build a "resolving" system, you should have the following:
1. Good power filtration (power filter, shielded power cords...)
2. Good vibration support (avoid stacking component on top of each other, avoid glass and metallic shelves, using appropriate footers and platform support...)
3. Low jitter source (low jitter transport, high performance and 75ohms compliant digital cable...)
4. Equipment with good temporal resolution (preferably little or no negative feedback, class A, high slew rate...)
5. Relatively transparent interconnects and headphone cables (high purity conductors, low loss dielectric...)
 
Most people focus on the equipment side (DACs, Headamps). Other experiment with power cords or interconnects. It is not very often however to find people who have addressed all those points.
Personally, I have found that those so called "tweaks" are essential to the good representation of the music. Those "tweaks" are in fact the foundation in building a resolving and musical system. One of the reasons the bigger and more expensive components sound good is that because they are more immune to external factors (power, vibration) than smaller and cheaper devices.
The good thing about having a good foundation is that you can use pretty much any equipment and it usually sounds good. Of course, the differences are there and they jump at you even more quickly than on non-optimized system, but there are fewer "incompatible" combinations.
 
A few days ago, I came across some measurements made by Nordost. Up to that moment, I had only my ears to tell that I heard a difference between the stock power cors and my €230/m power cords. 
I invite you to read the 2 articles below: one about the temporal resolution of human hearing and the other about the effects of power cables and vibration control devices on a CD player. Most people are unaware about the importance of the time domain and focus their time in comparing the frequency domain (frequency respone, THD) which are far less important to the subjective perceived sound.
http://www.physics.sc.edu/kunchur/Acoustics-papers.htm
http://www.nordost.com/downloads/New%20Approaches%20To%20Audio%20Measurement.pdf
 
This was perhaps a long answer for a short question, but I just wanted to explain the logic behind my upgrade path for those who were wondering. I am not saying I am not going to upgrade to the Ref7/phoenix at some point, but the "tweaks" that I have done so far have in fact provided me with an increase in performance and musicality far superior to what a change in components or even headphones for that matter can accomplish.
 
All of the above is of course my personal opinion and I don't pretend to hold be the absolute truth.

 

[SoupRKnowva]

wasnt expecting quite that lengthy of a response, but i appreciate it none the less slim.a, thank you. I cant believe how much you give to this community for free sometimes, you're a very professional writer, and always give well thought out responses to any questions anyone might have. you're an amazing asset for head-fi, if only you were coming to canjam so we could all meet the man the myth the legend slim.a   

 
that all makes sense though, i guess i just dont have the space right now to make all the other upgrades that you do, so its easier for me to just upgrade components. though i do feel that the amp would come last, with the headphones first and then the source next.

 

[slim.a]

Quote:

The LCD-2 is slightly better sounding than the T1 according to Skylab, but there is need to compare it with recabled T1 which may be quite equally good. The real pain with the LCD-2 is its "torture" comfort with its 550g, Skylab even said the improvement in SQ is not worth the pain relative to the overweight issue IIRC.
Since I already found the 260g of your HD650 to be a pleasure wearing on the head in comparison to the 350g of my T1 which is not very heavy anyway, I can't imagine with the 550g of the LCD-2, must be terrible.

You are right, the weight might indeed be an issue: your T1 already felt significantly heavier than the hd650. Thanks for the info on the weight of the LCD-2!

 

[kunalraiker]

Quote:

 

Yes, the dac19 was limited to 16/48. However, the usb chip that was being used previously on the dac19 (the pcm27xx) has been discontinued according to Audio-gd.
They are going to replace it with something else so maybe they are going to finaly use something that is not limited to 16/48. Somebody should ask Kingwa about it (I ask him way too many questions so I will let somebody else do it

).

I ordered the DAC19 yesterday,when Kingwa mentioned that the usb was back in stock,when asked about the details of  it,he didn't explain.