Ralf11 Posted November 18, 2017 Share Posted November 18, 2017 Is there a bottom line summary yet? Link to comment
mansr Posted November 18, 2017 Author Share Posted November 18, 2017 49 minutes ago, Ralf11 said: Is there a bottom line summary yet? Feel free to draw your own conclusions. Link to comment
GUTB Posted November 18, 2017 Share Posted November 18, 2017 Question, why aren't you using an Audio Precision analyzer? Link to comment
Miska Posted November 18, 2017 Share Posted November 18, 2017 4 hours ago, mansr said: The plots below are all normalised so a 1 kHz tone at 0 dBFS has its peak at 0 on the graph. Thanks, great! Signalyst - Developer of HQPlayer Pulse & Fidelity - Software Defined Amplifiers Link to comment
mansr Posted November 18, 2017 Author Share Posted November 18, 2017 22 minutes ago, GUTB said: Question, why aren't you using an Audio Precision analyzer? Because I don't have one. Les Habitants 1 Link to comment
PeterSt Posted November 19, 2017 Share Posted November 19, 2017 10 hours ago, mansr said: The plots below are all normalised so a 1 kHz tone at 0 dBFS has its peak at 0 on the graph. Ah, great. At any next opportunity, try to have the Y-axis "normally dividable" for the small ticks. Now it is 4dB which is unworkable. Generally there should be a small tick in the middle between two large ticks. So if large ticks are at 110, 100, 90, 80, there should at least be small ticks at 105, 95, 85 (in this case the small ticks are formed by the grid). Lush^3-e Lush^2 Blaxius^2.5 Ethernet^3 HDMI^2 XLR^2 XXHighEnd (developer) Phasure NOS1 24/768 Async USB DAC (manufacturer) Phasure Mach III Audio PC with Linear PSU (manufacturer) Orelino & Orelo MKII Speakers (designer/supplier) Link to comment
esldude Posted November 19, 2017 Share Posted November 19, 2017 45 minutes ago, PeterSt said: Ah, great. At any next opportunity, try to have the Y-axis "normally dividable" for the small ticks. Now it is 4dB which is unworkable. Generally there should be a small tick in the middle between two large ticks. So if large ticks are at 110, 100, 90, 80, there should at least be small ticks at 105, 95, 85 (in this case the small ticks are formed by the grid). Oh, and I prefer light green to the blue in the graphs. Or then again, maybe we are being awfully picky about nice measurements provided by someone else? Don't you think? I agree with lining it up near 0 dbFS. But come on, surely you can manage readings between the ticks. kumakuma 1 And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. Link to comment
semente Posted November 19, 2017 Share Posted November 19, 2017 On 16/11/2017 at 3:23 AM, mansr said: (...) That's a fairly large amount of harmonic distortion, significantly higher than for example the iFi nano iDSD, which to be fair is a much larger and more expensive device. (...) Did you publish measurements for the iFi? If so, could you provide a link? It would be very helpful if you would blog these. R "Science draws the wave, poetry fills it with water" Teixeira de Pascoaes HQPlayer Desktop / Mac mini → Intona 7054 → RME ADI-2 DAC FS (DSD256) Link to comment
mansr Posted November 19, 2017 Author Share Posted November 19, 2017 3 hours ago, semente said: Did you publish measurements for the iFi? No, but I could. Link to comment
semente Posted November 19, 2017 Share Posted November 19, 2017 4 hours ago, mansr said: No, but I could. If you find the time it would be appreciated. "Science draws the wave, poetry fills it with water" Teixeira de Pascoaes HQPlayer Desktop / Mac mini → Intona 7054 → RME ADI-2 DAC FS (DSD256) Link to comment
Popular Post mansr Posted December 19, 2017 Author Popular Post Share Posted December 19, 2017 And now for something a bit different, MQA. After some delays, a firmware update to the Dragonfly Black and Red gave them the ability to function as MQA "renderer." As previously discovered, MQA rendering consists of two parts: upsampling and shaped dither. Since the PIC32 microcontroller in the Dragonfly has very limited computing resources, it seemed unlikely that it would be able to handle the upsampling. As the ESS DAC chip has programmable filters, utilising these would be a reasonable alternative. Playing some MQA files, the sample rate sent to the DAC chip is indeed unchanged at 96 kHz. The ESS chip has a two-stage programmable FIR filter. The first stage is a fully programmable 128-tap filter. The second stage is a 28-tap symmetrical filter (only 14 values are programmed), meaning this stage is necessarily linear phase. The filter coefficients are programmed over I2C, so recovering them is trivial. These graphs show the impulse responses of the first filter stage. They all have the by now familiar basic shapes. The second stage filters are all simple triangle shapes of the same width but varying in height. Combining the two stages results in these impulse responses. This, finally, is the frequency response of the combined filters. Of course, the headphone amplifier has rather limited bandwidth, the actual output spectrum looks a little different. Here we see the spectrum up to 400 kHz with a white noise input using MQA filter 10. At low frequencies, the response is recognisable from the previous plot, then the limitations of the amplifier take over. Then there is the shaped dither. The ESS chip can't be made to perform this function, so it has to be done by the microcontroller. This is feasible as it requires far less CPU power than the resampling. This graph shows the recorded spectrum playing back silence using filter 3 and the each of the dither shaping options. Although the stream format allows four values for the shaping, two of them give the same output. Note the symmetry around 48 kHz. The dither is indeed applied before upsampling. Contrast this with the Bluesound which applies dither after upsampling. The digital output of the Bluesound renderer when upsampling to 192 kHz, while matching the shape from the Dragonfly, is stretched by a factor 2 and doesn't exhibit any symmetry. This is because here the dither is never subjected to the leaky MQA filters, and the shaping is able to concentrate the dither energy towards the highest frequencies as intended. In summary, MQA rendering on the Dragonfly works exactly as I theorised it would and Gordon Rankin vehemently denied. esldude, Fokus, opus101 and 10 others 8 1 4 Link to comment
Archimago Posted December 19, 2017 Share Posted December 19, 2017 Awsesome work Mans! MikeyFresh 1 Archimago's Musings: A "more objective" take for the Rational Audiophile. Beyond mere fidelity, into immersion and realism. R.I.P. MQA 2014-2023: Hyped product thanks to uneducated, uncritical advocates & captured press. Link to comment
Panelhead Posted December 19, 2017 Share Posted December 19, 2017 That is a very interesting result. I have never heard the Dragonfly. But the feedback on the sound quality of these is way better than the measurements. I did buy a HRT dac when the first model came out. Did not sound very good. Later saw the measurements and they were terrible. Was using an Apogee Duet FW and it was in a different class than the HRT Streamer. Since I have zero MQA files this feature is low importance to me. Liked seeing how a MQA dac could handle non encoded files in the Stereophile tests. Results looked the same as encoded files. 2012 Mac Mini, i5 - 2.5 GHz, 16 GB RAM. SSD, PM/PV software, Focusrite Clarett 4Pre 4 channel interface. Daysequerra M4.0X Broadcast monitor., My_Ref Evolution rev a , Klipsch La Scala II, Blue Sky Sub 12 Clarett used as ADC for vinyl rips. Corning Optical Thunderbolt cable used to connect computer to 4Pre. Dac fed by iFi iPower and Noise Trapper isolation transformer. Link to comment
semente Posted December 20, 2017 Share Posted December 20, 2017 17 hours ago, Panelhead said: That is a very interesting result. I have never heard the Dragonfly. But the feedback on the sound quality of these is way better than the measurements. There's nothing to be surprised about. People like what they like and their assessment is easily influenced by magazine reviews and hype... "Science draws the wave, poetry fills it with water" Teixeira de Pascoaes HQPlayer Desktop / Mac mini → Intona 7054 → RME ADI-2 DAC FS (DSD256) Link to comment
Popular Post mansr Posted December 20, 2017 Author Popular Post Share Posted December 20, 2017 49 minutes ago, semente said: There's nothing to be surprised about. People like what they like and their assessment is easily influenced by magazine reviews and hype... Moreover, while some of the graphs aren't pretty, and there are better-performing DACs, the distortions seen here are unlikely to be at an audible level when playing music. Human hearing just isn't all that great. tmtomh and adamdea 2 Link to comment
semente Posted December 20, 2017 Share Posted December 20, 2017 13 minutes ago, mansr said: Moreover, while some of the graphs aren't pretty, and there are better-performing DACs, the distortions seen here are unlikely to be at an audible level when playing music. Human hearing just isn't all that great. And people are generally listening for "sounds pleasing" instead of listening for "accurate reproduction" which is a difficult and not very effective task. Ultimately if people buy-by-ear in spite of the added harmonic distortion, bit of jitter or some other performance shortcoming. "Science draws the wave, poetry fills it with water" Teixeira de Pascoaes HQPlayer Desktop / Mac mini → Intona 7054 → RME ADI-2 DAC FS (DSD256) Link to comment
Samuel T Cogley Posted December 20, 2017 Share Posted December 20, 2017 5 hours ago, semente said: There's nothing to be surprised about. People like what they like and their assessment is easily influenced by magazine reviews and hype... Of course there is the notion that Audioquest is a trusted audiophile company, ergo they must produce only audiophile-grade gear. That's a lot of the expectation bias for some when listening to their products. Link to comment
sdolezalek Posted December 20, 2017 Share Posted December 20, 2017 4 hours ago, mansr said: Moreover, while some of the graphs aren't pretty, and there are better-performing DACs, the distortions seen here are unlikely to be at an audible level when playing music. Human hearing just isn't all that great. Yes. I greatly appreciate the work you have done in making all of these measurements. But you yourself are raising the natural question: Does it matter? What does your training/experience tell you as to which specific numbers should meaningfully influence our hearing? Put differently, is there one specification in which the Dragonfly falls short that, if improved, would greatly change its sound quality; or is it only the combined effect of a series of shortfalls, all or most of which would need to be addressed in order to produce meaningfully better sound? My gut would focus on the 96Khz clock and its inability to lock in on a 44 or 48 kHz signal, but you might say: "as bad as that looks in the graphs, your ears can't really hear the difference..." Synology NAS>i7-6700/32GB/NVIDIA QUADRO P4000 Win10>Qobuz+Tidal>Roon>HQPlayer>DSD512> Fiber Switch>Ultrarendu (NAA)>Holo Audio May KTE DAC> Bryston SP3 pre>Levinson No. 432 amps>Magnepan (MG20.1x2, CCR and MMC2x6) Link to comment
Popular Post Bufo Bill Posted December 20, 2017 Popular Post Share Posted December 20, 2017 You're assuming people are buying these based on sound. While this does sound better than just my laptop on its own, my chief reason for purchasing one of these was that it cost less than £90. Most of us here would probably buy the nicest sounding gear in our price range. For many people like me £90 is as much as we have to spend. The work by the OP is undoubtedly right, I am just saying that many people's first thought is not "what's the best sounding set up I can make" but more like "how can I make my system sound less like a coffee grinder with a bad motor for under a ton?" Regards from Bill. PeterSt, abrxx and tmtomh 3 Jriver, Windows 8.1, HP Pavilion G6 2215so Laptop, Dragonfly Black, Quad QCII Preamp, Quad FM 1 Radio, Quad II amp, Quad ESL Electrostatic speaker. Link to comment
hdo Posted December 22, 2017 Share Posted December 22, 2017 On 21/12/2017 at 3:35 AM, Bufo Bill said: While this does sound better than just my laptop on its own, Actually I bought because Dragonfly sounds louder than my laptop lineout. Later I found out that my laptop soundcard, which is Conexant HD Audio, does sound better than Dragonfly. I should have bought headphone amplifier using the money. tmtomh 1 Link to comment
Vitor Posted January 3, 2018 Share Posted January 3, 2018 What’s the alternative that the OP suggests as being cheaper and at least with the same performance as the black? In the beginning God made 'the light.' Shortly thereafter God made three big mistakes. The first mistake was called MAN, the second mistake was called WO-MAN, and the third mistake was the invention of THE POODLE. Link to comment
blownsi Posted January 3, 2018 Share Posted January 3, 2018 Would love to see comparison measurements on the DF Red. I have read numerous posts on other forums that the Black sounds horrible and the Red is great. Link to comment
mansr Posted January 3, 2018 Author Share Posted January 3, 2018 1 hour ago, blownsi said: Would love to see comparison measurements on the DF Red. I have read numerous posts on other forums that the Black sounds horrible and the Red is great. I have no intention of buying a Red. Sorry. Link to comment
mansr Posted January 3, 2018 Author Share Posted January 3, 2018 1 hour ago, Vitor said: What’s the alternative that the OP suggests as being cheaper and at least with the same performance as the black? I don't recall making such a suggestion. Link to comment
Vitor Posted January 3, 2018 Share Posted January 3, 2018 On 11/13/2017 at 6:46 PM, mansr said: Sounds like a driver issue. I have no problems at all with the standard usb-audio driver in Linux. It supports up to 24/96. As for sound quality, it's not terrible, but neither is it spectacular. There are probably cheaper devices that perform just as well. There you go. In the beginning God made 'the light.' Shortly thereafter God made three big mistakes. The first mistake was called MAN, the second mistake was called WO-MAN, and the third mistake was the invention of THE POODLE. Link to comment
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