The D7 "Sidewinder" is one of iBasso's latest portable USB DACs. It was originally going to use the rather stellar ES9018 32bit Sabre DAC but that was reserved for their DX100 model and the D7 was relegated to the more common Wolfson WM8740. It still ticks a couple of interesting boxes however: Firstly it's one of the cheapest asynchronous DACs around - £130 (although the Arcam rPAC is very close). It also supports the higher HD audio sample rate (192khz) over USB and has a 'class A' headphone amplifier. So does the D7's implementation make it stand out in this increasingly competitive arena or is it all bark and no bite?
SOUND
The signature of the D7 is on the dark side. As you push the volume up the first thing to notice is the low frequencies although they don't feel too bloated, just rather forward. They are reasonably well controlled and it includes a nice amount of detail - compared to a laptop it's a nice improvement. Getting the mid-tones more enjoyable and forcing some sparkle into the treble is a much harder task, all you can really do is keep pushing the volume up which just brings with it too many undesirably harsh artefacts.
The soundstage also shows improvement over a low end computer or even an entry level DAC but it's not quite the step up you might expect from something that cost nearly three times as much as the Fiio E7. In fact I would say that it's overall audio quality is somewhere between the Fiio E7 and Fiio E17 (review coming soon) but unfortunately that's not where it's priced. The Asynchronous USB connection, if it does anything at all, certainly didn't show any improvement over the audio quality of other DACs that don't have this feature.
I didn't feel that tthe D7's audio quality came close to the level from the HRT Headstreamer or Audinst HUD-MX1 and this is a shame given that these are the D7's direct rivals. As previously mentioned: I found even the Fiio E17 bests the iBasso in pretty much every way but mainly this was in the signature and soundstage departments. It's worth noting that most of my negativity is related to the D7's value. The audio quality is not bad, it's just uninspiring at this price.
CONNECTIONS & FEATURES
Unlike many other iBasso amplifiers the D7 doesn't have an internal battery or analogue input. The only other connection on the front is actually a line-out for bypassing it's internal amp, but I'm not sure how useful this is when it has RCA connectors available at the back. Also on the back you will find a coax digital output which means that you can use the D7 to computer a normal digital output for connecting it to an older DAC. This is interesting but, like with the Audinst, I really wonder who will buy it for this feature.
The volume dial also acts as the power on switch which feels unnecessary given that the Audinst doesn't need one at all. When you first turn it on it makes your headphones pop quite severely so maybe it's best not to connect them until after you've turned the D7 on. Generally I don't like this set up because you will have to play with the volume each and every time you turn it on. The dial is a rather badly finished piece of metal but it tuns fairly smoothly and without introducing any noise. There is plenty of volume here for moderately hungry headphones but the audio quality on the upper end of the volume pot diminishes somewhat.
SETTING UP
Unlike most other USB DACs the iBasso D7 is not plug and play which is due to the support of 192khz through it's only digital input. Windows drivers are not included in the box but are available from the iBasso website under the 'Downloads' section. Also, unlike most other DACs, even when the driver is installed (the D7 plugged in, turned on and detected) it doesn't get set as the default playback device. You really have to fight for this thing to work. It was listed as 'XMOS XS1-L1 Audio', in case you need to select it in Foobar. It's the only DAC I've tested so far that was detected as something not related to the product name. Once set as the default playback device though, there shouldn't be any further troubles.
Although generally the D7 was trouble free after this initial set up I did have a couple of issues with my laptop. Firstly the power failed when connected to any of the ports except one (turning the D7 off and bringing up a windows error message). It would only work on the USB port that's used to charge devices. This has never happened with any other USB DAC before or since. The second issue was that I could hear electrical interference through the amplifier (small crackling noises when you do things in Windows). This might only happen when connected to the powered USB port of the laptop but because it failed to work on the other two I wouldn't know if this could be avoided. Again, this has never happened with any other DAC, I thought it was an aspect limited to on-board soundcards but clearly not. This problem did not occur when the D7 was connected to either of my desktop PCs (the back of the computer or the monitor's USB hub) so it may not be a common issue but it's definitely not a good sign.
BUILD
The box that the D7 came in was plain white card, no text of any kind. The foam padding inside was very cheap. Although the box came wrapped in a layer of bubble wrap mine arrived all crushed on one side. Fortunately the unit survived but I get the impression that I was quite lucky. It seems that neither presentation or safety is exactly high up on iBasso's list of concerns.
There are a total of three lights on the D7. One at the back, two at the front and all different colours. This seems to be one to tell you it's powered, one to display a communication with the computer and one to show it's actually playing something. This might be useful given it's awkwardness to set up, but there are no instructions to tell you how to debug these signals and no way of stopping it look like a Christmas tree.
A decent amount of attention has gone in to the build quality of the D7 shell but it doesn't feel very well connected to the internals. The included accessories feel generic and lacking in consideration. The fact that you get two USB cables in the box (1.2m / 15cm) was my only pleasant surprise. You get a leather pouch which would be nice if it wasn't so fiddly to get in and out. With the feet attached it would be impossible to get the D7 in the pouch at all because the rubber pads are too large.
SUMMARY
The D7 is very rough product on so many levels. The packaging is terrible, the accessories are underwhelming and it looks like a Christmas tree when on. It has some nice features and a simple, straight forward design which is endearing, but the plug & play detection and drivers are a mess. Issues with the power, although fairly unusual, leave me thinking it's just not a finished product. Then there's the sound quality, it's not terrible but it really doesn't compare well to the competition.
If the D7 was cheaper, more reliable and could work without drivers I would have an easier time recommending it, but as it stands it gets lost in a sea of considerably higher quality and easier to use rivals.
And here are some older photos from an earlier attempt at writing this review...
