[stv014]

I have the Xonar D1, which is the PCI version of the DX, and according to my tests (some results are available here), it performs fairly well as a DAC, although I only tested the front channels. It is not great for driving many headphones because of the high (100 Ω) output impedance. The line input is decent, but it has no analog gain controls (so a 2Vrms input will always produce a 0 dBFS output on the ADC, but the signal may be amplified or attenuated digitally by the driver), the input impedance is relatively low (less than 4 kΩ), and the distortion is only really low if the signal is not above about -3 dBFS.
 
I do not know much about the DSX, other than what can be found out from the specs and pictures.
 
The DGX uses the same headphone amplifier (which is in fact a line driver only, and does not handle low impedance loads very well) as the Xonar U3 that has detailed measurements available at a well known blog, but it could have somewhat lower output impedance (based on pictures of the PCB only, no measurements are available). The DAC is better than on the U3, at least according to the specs and RMAA results I found.

 

[xnor]

Thanks a lot stv014, a wonderful article you did there. The DX manual mentions a line/mic-in preamp?!

 

[nick_charles]

Quote:

I have the Xonar D1, which is the PCI version of the DX, and according to my tests (some results are available here), it performs fairly well as a DAC, although I only tested the front channels. It is not great for driving many headphones because of the high (100 Ω) output impedance. The line input is decent, but it has no analog gain controls (so a 2Vrms input will always produce a 0 dBFS output on the ADC, but the signal may be amplified or attenuated digitally by the driver), the input impedance is relatively low (less than 4 kΩ), and the distortion is only really low if the signal is not above about -3 dBFS.
 
I do not know much about the DSX, other than what can be found out from the specs and pictures.
 
The DGX uses the same headphone amplifier (which is in fact a line driver only, and does not handle low impedance loads very well) as the Xonar U3 that has detailed measurements available at a well known blog, but it could have somewhat lower output impedance (based on pictures of the PCB only, no measurements are available). The DAC is better than on the U3, at least according to the specs and RMAA results I found.

 
 
Interesting. I followed the link to the Stereophile review where the reviewer liked it until they tested it against a much more expensive (and magazine favourite) $2500 DAC which apparently the reviewer preferred. Funnily though when you compare the measurements the STX is notably superior (30db better on IMD) in almost all regards but is summarized as "impressive" while the technically inferior but MUCH more expensive DAC is summarized as "Excellent" by the same measurer (JA). 

 

[Rebel975]

30dB difference seems like a lot. Shouldn't that be easily noticable?

 

[nick_charles]

Quote:

30dB difference seems like a lot. Shouldn't that be easily noticable?

 
 
Indeed, unless both have IMD below the audible threshold, however my suggestion was that the cheaper item was at least equal to the expensive one technically yet was perceived as definitely inferior in a rather sloppy uncontrolled sighted comparison and even when measured the cheaper but superior item was summarized in more guarded terms than an inferior but more expensive item. Remember of course that this is Stereophile where reviewers will turn a blind eye to 1% speed inaccuracies and 55db rumble figures but tut-tut at 900 picoseconds of jitter ! - what they let tube amps get away with is often criminal !

 

[Strangelove424]

Quote:

 
 
Interesting. I followed the link to the Stereophile review where the reviewer liked it until they tested it against a much more expensive (and magazine favourite) $2500 DAC which apparently the reviewer preferred. Funnily though when you compare the measurements the STX is notably superior (30db better on IMD) in almost all regards but is summarized as "impressive" while the technically inferior but MUCH more expensive DAC is summarized as "Excellent" by the same measurer (JA). 

 
I discovered a DAC that costs as much as a new car and have been unable to find specs or measurements for it (either official or magazine tested). Finding the specs has become an obsession for me because I simply don't understand how it could be possible. That's like buying a car without knowing the horsepower or fuel economy. When a reviewer states that the "decay is lovely and beautiful, and fades away ever so gently" how is someone supposed to tell that that's not an artifact of distortion, as lovely as it may sound? The more research I do, the more comfort I take in my STX. It was only $200, and comes with it's own test report that was measured with an Audio Precision SYS-2722 analyzer. There are audiophiles out there spending new car money who don't even get that. It boggles the mind. 

 

[nick_charles]

Quote:

 
I discovered a DAC that costs as much as a new car and have been unable to find specs or measurements for it (either official or magazine tested). Finding the specs has become an obsession for me because I simply don't understand how it could be possible. That's like buying a car without knowing the horsepower or fuel economy. When a reviewer states that the "decay is lovely and beautiful, and fades away ever so gently" how is someone supposed to tell that that's not an artifact of distortion, as lovely as it may sound? The more research I do, the more comfort I take in my STX. It was only $200, and comes with it's own test report that was measured with an Audio Precision SYS-2722 analyzer. There are audiophiles out there spending new car money who don't even get that. It boggles the mind. 

 
HA,! only a new car , how about http://www.stereophile.com/content/zanden-5000-mkivsignature-da-converter-2000-premium-cd-transport-specifications
 
and it is rank awful !

 

[Strangelove424]

Quote:

 
HA,! only a new car , how about http://www.stereophile.com/content/zanden-5000-mkivsignature-da-converter-2000-premium-cd-transport-specifications
 
and it is rank awful !

Jeez, those really are astoundingly awful measurements. And that price tag... just... wow.

 

[anetode]

Quote:

 
HA,! only a new car , how about http://www.stereophile.com/content/zanden-5000-mkivsignature-da-converter-2000-premium-cd-transport-specifications
 
and it is rank awful !

 
Classic example of JA resignation. I keep wondering, who actually cares what Fremer likes? He's a propagandist for overpriced crap.
 
The whole Japanese handmade craftsmanship in building audio products deserves greater scrutiny rather than the free pass of cultural respect which leads to tolerance of subpar products. Again, I'd rather have a product made by an engineer who depends on prior research than some over the hill savant who claims to have figured out the true cosmic nature of jitter and phase noise.

 

[ultrabike]

Quote:

Jeez, those really are astoundingly awful measurements. And that price tag... just... wow.

 
Not only measurements. Excerpts from "JA Takes a Listen" section:
 
"...there was nothing immediately or obviously bad about its sound other than a slight hum..."
"...could be heard to fur up the sound with a spray of low-order harmonics..."
"The Mozart Flute Quartet track on this CD sounded rather old-fashioned, in that it seemed a little band-limited..."
"This effect wasn't unpleasant, but was not what I thought I was capturing when I made the recording."
"...the image of the violin was a little diffuse."
"When music had no low-bass content, I didn't notice the lack..."
"...synthesizer-based rock and organ music will expose the Zanden's bass limitations..."
"Personally, I wouldn't recommend the Zanden pairing."
"...the Zanden just sounded more fuzzy."
 
'nuff said.

 

[anetode]

Final lines: "But again, I was surprised by how approachable the Zandens' presentation was at moderate playback levels, by how seductive this transport and DAC could sound. Score another one for the subjectivists, I suppose."
 
It's easy to read between the lines and understand what he's saying, but it's still taking the live and let live road. Now here's a proper review:
 

 

[stv014]

Quote:

The DX manual mentions a line/mic-in preamp?!

 
Well, it is not impossible, but I could not get a lower noise voltage using a microphone input than the line input (which seems to meet the 112 dB A-weighted dynamic range advertised by the specs of the card, and that translates to about 5 uV A-weighted RMS noise). In fact, it even seems to make the calculated input noise voltage worse than that of the line input. So, if there is an analog microphone pre-amplifier, it is not really useful, because using the line input and applying digital gain in software gives at least as good results. However, the microphone input does have a few V of DC voltage on it to power microphones.
 
On this picture, the analog input section of the more expensive Essence STX card can be seen well at the bottom left: the two JRC 5532 chips to the left of the CS5381 are the analog input buffer and lowpass filter circuit recommended by the Cirrus Logic datasheet, and the two RC4580 op amps further to the left are I think single ended to differential converters (one IC per channel, the "top" amplifier on the picture is non-inverting, while the other one is inverting with 2*4.7k resistors in the feedback loop, that is also close to the actual input impedance of the card). With a standard +5V analog power supply voltage, the CS5381 needs a 5.65 V differential input voltage for a 0 dBFS digital output, that is twice the voltage on the single ended line input.
 
The "ASUS DJ100" chip near the ADC is said to be a renamed C-Media AC97 codec, but I am not sure of its exact purpose.
 
I assume that the Xonar D1 and DX have a similar input design (although with lower quality components and implementation), but good pictures of the boards are harder to find, and the bottom side (where many components are also soldered) is rarely shown.

 

[Steve Eddy]

Quote:

Originally Posted by anetode /img/forum/go_quote.gif
 
 Now here's a proper review:
 

 
No no no, you have it all wrong. The Edition 10's sounded sooooooooo good, Tyll was actually having multiple eargasms.

 
se

 

[Strangelove424]

Quote:

Final lines: "But again, I was surprised by how approachable the Zandens' presentation was at moderate playback levels, by how seductive this transport and DAC could sound. Score another one for the subjectivists, I suppose."
 
It's easy to read between the lines and understand what he's saying, but it's still taking the live and let live road. Now here's a proper review:

 
LMAO@Tyll's review... that was awesome. Tyll can be a treble Pansy, but atleast he's honest about his own biases and opinions. That's all you can ask for in a review. Plus good measurements, which he does as well. 
 
I ignore the review sections on Stereophile now, but I went back because of the comments you guys were making. Once again, for the 1,583,498th review in a row, Fremer has rediscovered his entire music collection. I'd need heavier drugs to keep up all that rediscovering. The ironic thing is that is the one of several reviews by them I've read where the measurements disagreed with Fremer's subjective assessment, and I noticed a typical pattern emerges in the "follow up": adamant excuse-making, uming and ahing, adamant defense of the original review, and my personal favorite... the second test unit! It's a carnivalesque placebo demonstration or, as you noted, propaganda. I go straight to the measurement section now. The best thing they have going for them is a nice, expensive analyzer.

 

[doublea71]

LMAO@Strangelove - that is an amusing pattern you've found in his reviews and the guy sounds like he can't be honest or maybe he won't have any more high-ticket gear sent his way...oh the tangled web we weave, right? Makes me think about the CNET fiasco at CES...
 
Edited for a miniscule grammar error.