dalethorn Posted July 15, 2012 Share Posted July 15, 2012 When I connected the AudioQuest DragonFly to my computers I was pleasantly surprised that it interfaced perfectly with no configuration effort. Since the DragonFly is exactly like a typical USB thumb drive, excepting the 3.5 mm jack on the end where headphones and other output devices are connected, the only cable issues occur when you connect something other than a headphone such as powered speakers or a power amp to drive non-powered speakers. In such a case I would recommend a very high quality cable to maintain the full benefit of the DragonFly's sound processing properties. There is no physical volume control on the DragonFly, no doubt because it's just a small USB device the same size as a typical USB thumb drive. Since you'll need the computer's volume controls with the DragonFly, how they work on the different computers can be a minor challenge. On PC's using Foobar2000, I keep the Foobar volume slider all the way up and open the computer's volume window after Foobar is loaded. I suppose you could set the computer volume to maximum and then use the Foobar slider, but in my case the Foobar volume slider is so small I use the computer slider instead and that works fine. There may be cases where one method is better than the other sonically, but I didn't find that to be significant in my case. On the Apple Mac I use iTunes only with WAV-format files, and there I set the computer volume to maximum and used iTunes' volume slider instead. One thing I really like about the DragonFly besides the convenience of having a DAC and headphone amp in one little plug-in device is the fact that it doesn't get very warm in use. My air conditioner died about 36 hours ago and I've been running a laptop PC with the DragonFly in an indoor temperature ranging from 86 to 89 degrees F. While the DragonFly feels slightly warm after playing music for a couple of hours, it's surprisingly cool given the ambient temperature plus the fact that all of those electronics and the LED status light are contained in such a small package. The body is 1.75 inches long less the metal USB connector, the width is nearly 0.75 inches, and the height approximately 0.5 inches including the small hump on top which accomodates the 3.5 mm headphone jack. Fortunately the DragonFly includes a good secure cap for the USB connector, but I don't see a way to attach a lanyard to it. For those people who have been using the headphone jack on their desktop or laptop computers, and assuming that those computers have USB ports, they should expect better sound using the DragonFly instead of the computer's headphone jack. The actual improvement with my computers is a cleaner sound with a greater sense of "space" and "air" around the instruments. The fact that the DragonFly includes both a DAC and headphone amp in such a tiny package suggests to most audiophiles that the DragonFly's sound would be of much less quality than the typical separate DAC's and headphone amps selling for twice as much or more. I don't own the more expensive separates myself, but I have other DAC-plus-headphone-amp devices such as the HRT Headstreamer and Audioengine D1, and I have the HRT iStreamer DAC-only for Apple i-devices that I use with the Objective2 headphone amp. I don't hear anything to suggest that the DragonFly is less than a good upgrade to the computer's headphone output in spite of the very small size. Doing lengthy comparisons yesterday and today with the DragonFly and my other DAC-plus-headphone-amps, playing a variety of 96 khz music tracks downloaded from the HDTracks and DownloadsNow sites, I don't hear a significant difference between them. I did expect to hear some differences in the ultra-high-frequency harmonics and so on, but in spite of the amazing detail in these tracks and the resolution of the USB DAC/amp devices, there's so little difference that I could easily guess wrong about which is better than the other. I could tell rather easily that these 3 DAC/amps were better than the iStreamer plus Objective2 headphone amp (and I think the limiting factor there is the iStreamer) and better also than the FiiO E17 DAC/amp which has additional features. I'm going to take a guess here that since the DragonFly costs about $80 USD more than the Audioengine D1 and $110 more than the Headstreamer, and given the very small differences in sound (for the intended users at least), I expect people will buy the DragonFly because of the small size and convenience of not having to use a USB cable, or possibly other reasons. If such a small USB DAC were used with audio systems driving speakers, then one extra little cable would probably not make any difference, especially since the cable carries only digital data and the signal processing and jitter reduction occur after the cable in the DAC. But used with headphones, plugging the DragonFly directly into the USB port without a cable is a great convenience, especially when a laptop computer is being used away from the home desk/workstation. An important issue to consider when purchasing audio components to improve sound quality is detail, i.e. how much additional detail will be revealed in the music tracks by the new components. It's possible that a new audio component could reveal existing distortions in the recording in a way that makes them less pleasant to listen to, and some buyers may experience that dreaded feeling of "Uh-oh, I need to buy more stuff", or "Crap - this isn't working out the way I expected". I didn't have that issue with the DragonFly though - the sound was more revealing but less harsh, which is interesting since I would normally expect more harshness and sibilance with the greater detail. I suppose it's the natural result of having better components to process the data in those digital music tracks. Questions have come up in several places as to whether a typical computer's USB port can supply enough power to run the DragonFly's DAC and headphone amp, to provide good volume especially in the bass where the greatest power demands occur, and to have enough headroom to avoid clipping or otherwise distorting the loudest most dynamic music passages. The answer seems to be yes, since I have many FLAC format music tracks with a 96 khz data rate that have extreme dynamics which distort noticeably when sufficient power is not available. Some of those tracks that I've made 320k MP3 copies of for playing on the iPhone will not play on the iPhone at the full volume I prefer because of the extreme dynamics, however those same MP3's will play without clipping on the computer using the DragonFly DAC and headphone amp. Headphones tested with include the Shure 1840, Philips L1, ATH M50, and B&W P3/P5. Link to comment
50000 Posted July 15, 2012 Share Posted July 15, 2012 Questions have come up in several places as to whether a typical computer's USB port can supply enough power to run the DragonFly's DAC and headphone amp, to provide good volume especially in the bass where the greatest power demands occur, and to have enough headroom to avoid clipping or otherwise distorting the loudest most dynamic music passages. The answer seems to be yes ... Another question is whether the current drawn by headphones will modulate the supply and thereby cause jitter and how much. The single USB supply supplies both digital and analogue circuitry. My listening suggests this modulation occurs. Link to comment
dalethorn Posted July 15, 2012 Author Share Posted July 15, 2012 Another question is whether the current drawn by headphones will modulate the supply and thereby cause jitter and how much. The single USB supply supplies both digital and analogue circuitry. My listening suggests this modulation occurs. I would have guessed the same. But at least one of the 3 DAC/amps I compared claims separate power supplies to eliminate that problem. Whatever the case, I don't find a significant difference in the sound of any of these three. I could be overlooking something, but it sure doesn't make itself obvious. Link to comment
AudioDoctor Posted July 15, 2012 Share Posted July 15, 2012 word! haha! No electron left behind. Link to comment
Old Listener Posted July 15, 2012 Share Posted July 15, 2012 dalethorn, Good post. Good info, good analysis. What level of CPU utilization are you seeing playing music through the DragonFly? Some USB DACs seem to consume about 20-25% of CPU resources. Bill Link to comment
AudioDoctor Posted July 15, 2012 Share Posted July 15, 2012 dalethorn, Good post. Good info, good analysis. What level of CPU utilization are you seeing playing music through the DragonFly? Some USB DACs seem to consume about 20-25% of CPU resources. Bill Which USB DACs were you seeing use 20-25% of CPU resources? Was there software up sampling going on at the time? No electron left behind. Link to comment
dalethorn Posted July 16, 2012 Author Share Posted July 16, 2012 Which USB DACs were you seeing use 20-25% of CPU resources? Was there software up sampling going on at the time? In Task Manager, I set Priority to high with Foobar to minimize interruptions and sorted the list top down to show the resource hogs at the top, yet most of the time Foobar showed zero percent. I had to turn Skype off completely because even on low priority it kept interrupting the sound. After turning off Skype, the only process that bumped up on the list occasionally was the virus/security checker, Macafee. That was on the 3.4 ghz Dell with 16 gb RAM and Win7-64. On my 1.2 ghz netbook with one gb RAM and WinXP, and that netbook never connects to a network or internet, I didn't have to bother and never got interrupted. So my experience is no matter how powerful the PC, Foobar2000 can have problems. I use the WASAPI (event) : Speakers (DACname) output setting. Link to comment
dalethorn Posted July 16, 2012 Author Share Posted July 16, 2012 The Youtube video here also has a summary of the other 4 DAC/amp options I'm using: Audioquest Dragonfly DAC plus Headphone Amp review by Dale - YouTube [video=youtube_share;NSVu-ZeBH-A]http://youtu.be/NSVu-ZeBH-A Link to comment
Old Listener Posted July 16, 2012 Share Posted July 16, 2012 Which USB DACs were you seeing use 20-25% of CPU resources? Was there software up sampling going on at the time? I saw that sort of resource use on a 6 year old desktop PC with 2.4 MHz dual core AMD CPU running JRiver MC under XP with an Audioengine AW1 DAC (adaptive mode). On a modern desktop with a quad core Sandy Bridge i5-2400 CPU with a cheap Behringer UCA-202 USB DAC (adaptive mode), I am seeing short spikes of 7% and 10% CPU utilization. I do not see similar spikes using onboard sound or a PCI soundcard. These observations were made using Task Manager's Performance Tab which shows overall CPU use. In this case, I'm interested in CPU use at the interrupt handler level and the DPC level. Here is the context for my question about CPU use for the Dragonfly: - I may move to using 3 USB DACS on my dedicated MusicPC to provide different audio streams to 3 rooms. Two of those streams might be active at one time. Right now I use SPDIF output from a PCI soundcard for 2 rooms and a USB DAC for the third room. - An async mode DAC probably requires more action from interrupt level and DPC level software than an adaptive mode DAC does. (To adjust the number of samples in packets sent to the async more DAC.) In Task Manager, I set Priority to high with Foobar to minimize interruptions and sorted the list top down to show the resource hogs at the top, yet most of the time Foobar showed zero percent. I had to turn Skype off completely because even on low priority it kept interrupting the sound. After turning off Skype, the only process that bumped up on the list occasionally was the virus/security checker, Macafee. That was on the 3.4 ghz Dell with 16 gb RAM and Win7-64. On my 1.2 ghz netbook with one gb RAM and WinXP, and that netbook never connects to a network or internet, I didn't have to bother and never got interrupted. So my experience is no matter how powerful the PC, Foobar2000 can have problems. I use the WASAPI (event) : Speakers (DACname) output setting. My question was about overall CPU utilization. As I explained, I was interested in the overall number you see in Task Manager's Performance tab with an async mode DAC in use. I've done my share of watching resource use in Task Manager and other tools such as DPC latency checker. I have tuned my MusicPC and my personal PC to run without glitches. It sound as though you have done similar work. Bill Link to comment
dalethorn Posted July 16, 2012 Author Share Posted July 16, 2012 My question was about overall CPU utilization. As I explained, I was interested in the overall number you see in Task Manager's Performance tab with an async mode DAC in use. I've done my share of watching resource use in Task Manager and other tools such as DPC latency checker. I have tuned my MusicPC and my personal PC to run without glitches. It sound as though you have done similar work. Bill Sounds like you're way ahead of me on this. To me, Task Manager alone is too crude to see what's going on because of the way different approaches some of those tasks are utilizing. I've tried using Process Explorer and Process Monitor (and maybe some others) to see what different programs were doing to memory and files both, and I get lost in that pretty easily. Imagine for a moment that your music player were trying to open a file that's locked exclusively by another task. OK, it happens but ..... I also want to run several DACs simultaneously, just for convenience in testing. Maybe I can figure out a way to do that using something besides WASAPI? No idea at this point. Link to comment
Old Listener Posted July 16, 2012 Share Posted July 16, 2012 To me, Task Manager alone is too crude to see what's going on because of the way different approaches some of those tasks are utilizing. Well, I customize the columns in the processes tab and look for activity. An exercise in peripheral vision. > Imagine for a moment that your music player were trying to open a file that's locked exclusively by another task. > OK, it happens but ..... I didn't understand at all. > I also want to run several DACs simultaneously, just for convenience in testing. > Maybe I can figure out a way to do that using something besides WASAPI? No idea at this point. I no longer use Foobar to play music so I don't know about outing to more than one device in Foobar. In JRiver MC, I can define a separate playback zone for each room and set the output device for each zone. You can mix DirectSound, ASIO and WASAPI for the different zones as you like. --- I'd still like to know about the overall CPU utilization you are seeing with DragonFly. Bill Link to comment
dalethorn Posted July 16, 2012 Author Share Posted July 16, 2012 I'd still like to know about the overall CPU utilization you are seeing with DragonFly. Not sure what else to look for. Got CPU Usage column and CPU Time column. Sorting by CPU Usage System Idle is always 99 percent and every now and then Skype or Macafee breaks zero. Sort by CPU Time and System Idle is 273:nn:nn with the last 'nn' changing rapidly, VPC is 0:39:22 (doesn't change), Skype is 0:09:11 (doesn't change), Macafee is 0:08:20 (changes occasionally), WASAPIHost64 is 0:00:03 (changes rarely), Foobar is 0:00:03 (changes rarely), and I don't see an image name for the Dragonfly. This is with playback of some 96k tracks going on. Link to comment
Old Listener Posted July 16, 2012 Share Posted July 16, 2012 Not sure what else to look for. Got CPU Usage column and CPU Time column. Sorting by CPU Usage System Idle is always 99 percent and every now and then Skype or Macafee breaks zero. Sort by CPU Time and System Idle is 273:nn:nn with the last 'nn' changing rapidly, VPC is 0:39:22 (doesn't change), Skype is 0:09:11 (doesn't change), Macafee is 0:08:20 (changes occasionally), WASAPIHost64 is 0:00:03 (changes rarely), Foobar is 0:00:03 (changes rarely), and I don't see an image name for the Dragonfly. I asked about overall CPU utilization which you can see graphed in the Performance tab. CPU activity in a interrupt routine or at the DRC level will probably not be shown in the figures for any process. Bill Link to comment
wgscott Posted July 17, 2012 Share Posted July 17, 2012 No driver. No process in OS X either. Therefore, no CPU activity is reported. Probably the same on Windows, since there is no driver required, even for that OS. This is one of the huge advantages of having something like this, or one of the Halide products, in my opinion. The ability to run this thing without a "driver" or kernel extension greatly enhances stability, ease of use, potentially CPU consumption (although kernel extensions shouldn't chew up much CPU), and versatility (no need to slave it to a particular OS or even have to worry about OS upgrades). That, in my mind, more than makes up for its inability to play 192kHz, which even my dogs can't properly appreciate. Link to comment
dalethorn Posted July 17, 2012 Author Share Posted July 17, 2012 No driver. No process in OS X either. Therefore, no CPU activity is reported. Probably the same on Windows, since there is no driver required, even for that OS. Although I don't see activity in the CPU Usage column, the total time accumulated in the CPU Time column does increase slowly, which I suppose means the CPU doesn't have to concern itself with the DAC from moment to moment. That process is apparently delegated to some secondary I/O chips and software. Those things can be found through various PC utilities. Link to comment
Old Listener Posted July 17, 2012 Share Posted July 17, 2012 No driver. No process in OS X either. Therefore, no CPU activity is reported. Probably the same on Windows, since there is no driver required, even for that OS. This is one of the huge advantages of having something like this, or one of the Halide products, in my opinion. The ability to run this thing without a "driver" or kernel extension greatly enhances stability, ease of use, potentially CPU consumption (although kernel extensions shouldn't chew up much CPU), and versatility (no need to slave it to a particular OS or even have to worry about OS upgrades). When I wrote my last post, I wondered if someone would make the argument you made. USB DACs require driver level support in the Windows environment. Many USB DACs rely on drivers provided as part of the Windows installation. Those drivers in the Windows installation may or may not have been written by Microsoft. The question is whether the drivers provided with Windows will work better than those provided by the USB DAC vendor. Although I don't see activity in the CPU Usage column, ... That is what I was asking for. Thanks. Bill Link to comment
wgscott Posted July 17, 2012 Share Posted July 17, 2012 The question is whether the drivers provided with Windows will work better than those provided by the USB DAC vendor. The answer is that no driver is provided by the USB DAC vendor (apart from what is embedded in the firmware of the DAC itself). Link to comment
wgscott Posted July 17, 2012 Share Posted July 17, 2012 Right now, I am finding this thing is no longer capable of staying plugged in properly to the rear USB port of my iMac. Under the (minimal) weight of the cable, due to the non-flush connection, it begins to sag slightly, and this disrupts contact, and therefore playback. It was fine when I first got it. Link to comment
dalethorn Posted July 18, 2012 Author Share Posted July 18, 2012 Right now, I am finding this thing is no longer capable of staying plugged in properly to the rear USB port of my iMac. Under the (minimal) weight of the cable, due to the non-flush connection, it begins to sag slightly, and this disrupts contact, and therefore playback. It was fine when I first got it. Please send a message to Audioquest and let us know what they say. Link to comment
thrand1 Posted July 19, 2012 Share Posted July 19, 2012 Dale, Thanks for the review...from what you wrote I take it the Dragonfly adequately powered all of the headphones you listed? I am considering this along with the ODAC/Music Streamer II for use as a USB DAC, and am wondering if having a built in headphone amp is beneficial. I have Shure SRH940 headphones (similar impedance/sensitivity to your ATH-M50) and was wondering in your opinion if the headphone amplifier on the Dragonfly would be adequate enough that I wouldn't necessarily need a separate headphone amp for the 940s? I have been going back and forth on whether the 940s "need" an amp like the O2 or JDSLabs C421, and I know you owned the 940s at one point in time, so your insight is appreciated. Thanks again! -Tyler Office: iPod classic/iPad -> Shure SE425 IEM Home: Oppo BDP-83/Synology DS211j -> Integra DTR-7.8 -> Revel speakers Link to comment
dalethorn Posted July 19, 2012 Author Share Posted July 19, 2012 Dale, Thanks for the review...from what you wrote I take it the Dragonfly adequately powered all of the headphones you listed? I am considering this along with the ODAC/Music Streamer II for use as a USB DAC, and am wondering if having a built in headphone amp is beneficial. I have Shure SRH940 headphones (similar impedance/sensitivity to your ATH-M50) and was wondering in your opinion if the headphone amplifier on the Dragonfly would be adequate enough that I wouldn't necessarily need a separate headphone amp for the 940s? I have been going back and forth on whether the 940s "need" an amp like the O2 or JDSLabs C421, and I know you owned the 940s at one point in time, so your insight is appreciated. Thanks again! -Tyler The Dragonfly will easily power the SRH940 headphone, although it's hard to imagine sometimes being so small. I read a lot of other reviews (well, not a lot but as much as I could find) on the Dragonfly, and I got the idea that the overall impressions were that it's slightly bright. I don't find it any different than the Headstreamer or Audioengine D1 in that respect, so maybe that impression just goes with this type of device somehow. Whatever the case, since the SRH940 has such strong high frequency detail, there is the possibility that the Dragonfly could over-emphasize that detail. I don't have the 940 with me now so I can't do that evaluation. But here's my suggestion: The quality of the Dragonfly's sound from DAC in to headphone out is excellent, so if I were using it with the SRH940 and I found it a little too crispy on the high end (and I'm sure that would apply to those other DAC/amp combos too), I would do the earcup/foam mod that worked so well with the SRH1440 instead of looking for something with less detail. One user who reported on his tests of the SRH940 at the Headfonics site, named Amclaussen, described his experience using the Lehmann Audio Black Cube as quite amazing, but that's a fairly high priced option. Link to comment
Wavelength Posted July 19, 2012 Share Posted July 19, 2012 Gang, Just a couple of things to clarify your experience. The DragonFly does not draw that much power in normal use. Out of the available 500ma, the DragonFly really uses only about 1/5th of this with normal usage. Since there are numerous regulations stages, no more jitter will be experienced with use from Line or Headphone usage. The DragonFly is compliant with USB Class 1 standard Asynchronous Audio and is therefore compatible with all operating systems without the need for any drivers. There are no drivers downloaded from the DragonFly nor are there any required for this product to work on Windows or other operating systems. Windows does require a driver for Class 2 Audio but that is not used here and therefore not required. The volume control falls into standard enumerated device technology under the USB Feature set and is also falls into standard non-driver required software for all operating systems. The CPU utilization for the dac would be the same for any Class oriented Audio device and is more a case of the software and not the device. DACs that require custom drivers can increase the overall system resources. I did work heavily with Apple, Microsoft and even Linux developers on the Asynchronous drivers shipped with their os. Thanks Gordon Because of it's form factor the use of the new DragonTail may make the product work better in your implementation, this especially true for the iMac and some laptops that have close quarters. J. Gordon Rankin Wavelength Audio http://www.usbdacs.com/ http://www.wavelengthaudio.com/ http://www.guitar-engines.com/ Link to comment
HiFiInsider Posted July 19, 2012 Share Posted July 19, 2012 Gordon, Do you know if my $0.99 generic 1ft DragonTail cable will degrade the sound? Do you have any update on the real DragonTail cable? http://www.youtube.com/hifiguy528/videos Link to comment
dalethorn Posted July 19, 2012 Author Share Posted July 19, 2012 If the signal going through the USB 'tail' is unprocessed digital data that will be cleaned up by the DAC, what penalty could there be to having the extra USB cable ahead of the DAC? Link to comment
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