REVIEW: QED uPlay Stream network audio player
Despite it being a device that is principally about providing access to network digital audio, the QED Stream network audio player seems quite firmly directed at the analogue market. Stephen Dawson explains.
QED is best known among home entertainment aficionados for its high end audio and, more recently, video cables. Its uPlay Stream network audio player is, obviously, a very different thing indeed.
What it is
The QED uPlay Stream is, in technical terms, a digital audio ‘renderer’. In other words it streams digital audio from DLNA-compatible network devices and it decodes them to audio. It is entirely focussed on this task alone; there is no provision for internet access, nor does it offer such extras as Bluetooth support.
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QED has a couple of Bluetooth-only devices for that purpose.
It is a tiny device – shaped like an oval puck, it’s only 112mm wide, 95mm deep and 26mm tall, and weighs just 77g. Being so small, placement should be no problem. But given QED’s heritage, you’ll likely want to use the included audio cable, which offers only a little more than 600mm of reach.
Input to the device is via the Ethernet port or WiFi. Output is via the analogue audio output only. This is very high quality audio output since the unit features a Wolfson 24 bit, 96kHz DAC.
I do have one significant issue with the output: presumably in the interests of saving space, the output is a 3.5mm stereo socket, of the kind used for earphone outputs and the like. I would have preferred the greater contact area available from standard RCA sockets.
Still, 3.5mm connections seem to have become far more reliable as they’ve become quite ubiquitous, and I’ll take it on trust that QED would have incorporated the best socket they could find. It certainly worked with perfect reliability throughout the test period, both with the cable supplied by QED and my own much heavier cables attached to a 3.5mm to RCA converter plug.
The unit supports a good range of audio formats: FLAC, ALAC (Apple Lossless), AAC (including iTunes format), AIFF, MP3, WAV and WMA. With the lossless formats it supports up to 96kHz sampling and 24 bits.
The manual notes that the unit ‘plays audio tracks up to 24-bit 96kHz. However, the DAC will down-convert 24-bit resolution to 16bit and output at 16-bit resolution.’ I confirmed this with QED: while the DAC is capable of handling 24 bit files, the streaming hardware handles only 16 bit sound.
No remote control is provided with the unit, but none is needed. Not even to switch it off, really. Its power consumption when running is a tiny 1.9W, so you may as well just leave it on.
WiFi is most easily set-up using the WPS key on your router, if it has one. Otherwise you can wire the unit temporarily into your network and set up the WiFi using its internal setup web page.
App
Since the uPlay Stream has no controls, it has to be driven from elsewhere. That elsewhere is a computer, tablet or phone. With Windows computers you can simply select the unit as an output device, just as though it were any other DLNA compatible client, from within Windows Media Player, and use that software as your controller to select tracks and play, pause, repeat and so on. For Macs there is software downloadable from QED’s site.
But the norm will be to use the phone/tablet app, freely available from the Apple and Android stores. I used the respective versions on an iPad Mini and an 8” Android tablet, and operation was effectively identical for both.
There are five buttons across the bottom of the screen. One is to choose the device to which the music is to be routed. Typically this will just be your uPlay Stream. But you might have several (up to eight are supported on one network) so you can select which one you want to play to. You can also group them into a number of combinations and choose the group instead. You can change the name of each device (e.g. to reflect its location in the house) by accessing its internal web page with a browser, or via the app.
Another button is for selecting the source. That can be the library of music on tablet or phone itself, or any DLNA servers available on your network. Or music from any cloud service to which you are signed up. The app happily played back MP3s from both my Dropbox and OneDrive (formerly SkyDrive) accounts.
There’s a button for managing the queue of currently playing material, and another for creating and managing playlists.
Finally there’s the ‘Player’ button, which brings up the main player control page. From this you can skip tracks, pause, set up random and repeat playback, drag a slider to move to any point in the current track, and mute the sound or adjust the volume. The volume control is in two forms: a slider and a virtual thumb wheel, which are easily switched between.
The app is very intuitive, easy to operate, elegant in design and fast in bringing up lists of artists, albums and so on. Perhaps a quicker way to get back to the root of sources, rather than having to back out level by level, would be an improvement, but that’s the only one that occurs to me.
Of course, you can use a different app if you prefer, such as BubbleUPNP on Android.
Sound
The sound quality of the unit was as with analogue playback from a high quality CD player: smooth and clean, with no apparent degradation of the signal. That’s using FLAC of course. The unit also seemed to decode the various MP3, AAC and WMA tracks I tried flawlessly.
My FLAC music up to 24 bit, 96kHz was played perfectly. The 192kHz content was not played at all, the app announcing that these tracks were incompatible.
There was an issue with a couple of CD tracks when I had the app’s volume control advanced to the maximum level. For example on the track Kometenmelodie 1 from the 2009 remaster of Kraftwerk’s Autobahn album, the bass rhythm peaks above the -1dB full scale point fairly frequently and a number of these were accompanied by a brief crackle, as though something were overloading. Playing around with the volume control on the app revealed that winding it down to below 95% eliminated this, even if I turned up the amp to compensate for the reduced volume.
The unit’s specifications say that its maximum output is greater than 1.4V peak to peak, so it didn’t seem likely that the problem was with an overload of the amp. To check I created a 1.001kHz sine wave modulated to the full 16 bit scale (i.e. 0dBFS), which is as loud as it could go, and played it on the uPlay Stream*. The measured output was indeed about 1.43V, but RMS, not peak to peak. That equates to a bit over 4V peak to peak. And the output is simply too high for the hardware. At every volume position from 95 up to 100, the sound was tainted with massive levels of odd-order harmonic distortion. At 94 and below it was perfectly clean.
For the first time in several years I pulled out my cathode ray oscilloscope to look at the waveform. At 94 the form of the sine wave was perfect. At 95 there was hard clipping at the top and bottom of the waveform. At each higher level the clipping was more severe. The geometric precision of the clipping made it look like it was digital rather than analogue clipping. That is, the clipping may have been introduced in the digital volume control, rather than overloading the analogue output stage.
While I am tempted to suggest that QED should have set the maximum output level to the equivalent the current 94, I suspect that I was using the system wrong.
Where the output level of a device is adjustable, I always set it to maximum level and then adjust the volume with my amplifier’s controls. That’s an old habit derived from the days when amplifiers used to generate significant internal noise, so a high input level helped keep that down.
I’m thinking, though, that the best way to use this device – especially if it becomes your main music source – is to play with your amp’s volume control so that an output of 94 is as loud as you will ever want to play the system, and then use the app’s volume control to set the listening level you want. The only time you will ever want to push its level up beyond 94 is where the content is modulated at such a low level that there’s no danger of clipping.
Conclusion
So, if you take that usage note into account, you’ll find that the QED uPlay Stream is an excellent high fidelity DLNA music streamer, with a first class control app, available at quite a reasonable price.
*Be extremely careful if you ever want to do something similar. It’s far too easy to blow loudspeakers, amplifiers and even your ears with this kind of test signal. I set the name, genre, album and artist of this track to ‘Danger’.
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