CHANGSTAR: Audiophile Headphone Reviews and Early 90s Style BBS
Lobby => Amp and DAC Measurements => Topic started by: firev1 on May 06, 2014, 11:21:43 AM
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(http://i.want.tf/to/that/0tkEHSj.png)
Over the last weekend, a friend who I was helping with some IEM work passed me the DX90, it uses Dual 9018K2M chips. Sadly I only have subjective impressions rather then a conclusive statement but I can safely say that it has the stereotypical "9018 glare" that we have come to expect from Sabre devices. It sounds pretty wide and "detailed"(not sure if real resolution or fake detail since I'm not really into porta-fi) but stuff like cymbals I feel are given a longer decay of sorts which makes it sound harsh. For most of the time I'm using it with the X10, IM-70 and AKG 240DF so take my opinions with huge grains of salt.
Chain: DX90(line out)->y cable 1/8" to RCA and RCA to 1/4" adapters -> EMU0404-> Fujitsu Lifebook
Test sample rate is 24/48.
For this DAP, I think it essentially sounds like it measures, with THD it has multiple higher order distortions which are present.
With intermodulation distortion test though, it seems to perform very very well, exceeding the resolution of the 0404 I feel however, high frequency IMD is worse then the 0404 which I think is caused by the large amount of low level jitter(you can see it affecting the base of fundamental signals in THD measurements and 12khz jitter tone) from the DX90. So much for the ASRC and Hyperstream in the 9018K2M chip.
Conclusion, don't get this if you are not a Sabre fanboy walk the plank
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Hey fire, thanks for the measurements!
Subjectively, I agree with your findings. I honestly didn't notice the treble glare that much when using the dx90 alone with the UERMs but yesterday when I was taking the bus/train for nearly 4 hours, it was very evident when I added the UHA-6s (ada4627) to the chain. The treble was glaring, the cymbals were hot, and the bass lacked tone. Overall I think i'm just going to use the dx90 unamped since it seems like the amp section helps in hiding the sabre treble.
I did some comparisons between the dx90 and gungnir using the uha-6s and UERMs. It's not exactly a fair comparison considering the gungnir is more expensive and can be used as a weapon... but here's what i found (uneditted notes):
ARIA - Gungnir had bigger soundstage with a more filled in sound. More bass presence and body. Slight better seperation. Better vocal tone.
Hanamatsuri - Gungnir had much more sub bass rumble and tone. Livelier, but still smooth.
Stich'step - GUngnir had better bass tone but feels like the dx90 had more bass quanitity. dx90's treble was a bit harsh in comparison .
black or white - gungnir with better layering and smoother treble plus better vocal tone
feel so good - better soundstaging with more filled in sound. more impact. dx90 a bit leaner in comparison
view of the river styx - Both were clean with the drums. dx90 brighter with the highhats of course. A bit more treble splash. Better guitar tone on gungnir
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I thought the unamped DX90 was pretty decent in that it could drive almost all headphones without the feeling that the headphone is underdriven and did not as small or congest vs the Ipod Touch 4g(as a DAC) least when driving the HD800s. The impressions are done with the phones out, I listen to a lot of songs with sibilance so it really does not mince well with the DX90(which makes it worse).
The two are a terribad pairing though, the treble glare really gets to me.
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Yeah the dx90 is pretty good at making me feel that I don't particularly need an amp. The hd600s, enigmas and uerms work well straight out of the dx90.
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Insanely powerful for the size!!
It pairs well with the MartinCustom woodied HE500 that Marv measured a year ago. But even so, I do notice that glare.
And when I put on my Ultrasone Ed8s... my ears bleed a little...
At first I thought it was just me getting older and not really that into sparkly treble, but after reading this entire thread I understand now what I'm hearing....
LCD3 is another great pairing. This little 'toy' can drive most full sized cans without feeling like I need more power!
Oh... and this thing here.... I was wondering what it was... and when I found out I fell off my chair.
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Can someone explain jitter? Is it some kind of distortion? And how does it matter if it's 100 dB below the signal?
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http://nwavguy.blogspot.com/2011/02/jitter-does-it-matter.html
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http://nwavguy.blogspot.com/2011/02/jitter-does-it-matter.html
Eff, that guy.
http://www.stereophile.com/content/case-jitters
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Thanks for the links. Several questions:
1. Shouldn't a 11.025 kHz tone be used to measure jitter? My bad, didn't see 48 kHz sample rate was used. facepalm
2. The noise floor and the sideband show great performance, even compared to some high end CD players. Only the spread looks problematic (=weak bass performance). Is that enough to ruin the overall performance of the DAP?
According to that nwavguy site it shouldn't be audible.
3. Is there a better performing portable DAP in the price range of the DX90?
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I think bass lacking tone should provide some impression of what performance impact this type of jitter gives. I would not say that jitter should be the only factor that results in the performance of the player but also how the distortion is distributed(3rd order, high amplitude of multiple orders of distortion).
For further reading Benchmark has a paper on jitter and how it impacts digital filter performance.
http://benchmarkmedia.com/blogs/white-papers/12142221-jitter
Another JA article on jitter, this one is very digestable as well, 1 page with the final paragraph on the audibility of jitter.
http://www.stereophile.com/reference/1290jitter/
The Geek Wave seems to be the DAP to wait out for by other pirates meet impressions, I look forward to seeing the reviews and hearing it :3 I have not tried the Fiio ones at this point of time.
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http://nwavguy.blogspot.com/2011/02/jitter-does-it-matter.html
Eff, that guy.
http://www.stereophile.com/content/case-jitters
One of them always tells the truth, and one of them always lies. You can only pose one question to one of them to figure out which one's which. Choose wisely.
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The dx90 doesn't go well with super bright or sibilant prone headphones but I feel that the sabre treble was significantly toned down via upgraded batteries (just a good samsung s3 battery will do) and the 2.1.0 international custom firmware by lurker.
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http://nwavguy.blogspot.com/2011/02/jitter-does-it-matter.html
Eff, that guy.
http://www.stereophile.com/content/case-jitters
One of them always tells the truth, and one of them always lies. You can only pose one question to one of them to figure out which one's which. Choose wisely.
Do I get to touch the door knob to check for heat?
https://www.youtube.com/watch?v=f8opY80dhYc
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Do I get to touch the door knob to check for heat?
Indiscriminately touching strangers' knobs isn't going to help you this time, I'm afraid.
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The dx90 doesn't go well with super bright or sibilant prone headphones but I feel that the sabre treble was significantly toned down via upgraded batteries (just a good samsung s3 battery will do) and the 2.1.0 international custom firmware by lurker.
Any DAP will sound bad with super bright and sibilant headohones. That's not the DAP's fault.
Is it even possible that the battery can alter sound? I don't see how that could happen.
Edit: The dudes in the head-fi sound science forum agree that the jitter measurement is fine and the jitter should be completely inaudible.
I also don't see or hear anything that resembles glare. The 3rd order harmonic is 100 dB below the signal. Dunno how that could matter.
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Unfortunately, we are not as smart as the dudes in the HF sound science forum in regards to understanding jitter. Here, we are still way way behind - trying to see if there's any correlation of subjective observations to measurements. Hopefully this will change in time with more jitter measurements of different gear being performed the same way with better measurement instrumentation.
Right now we are just playing with some of these measurements more out of curiosity than delivering the truth.