The TeraDak U9VA PSU does not come with a mains power cord, but it does include the two cables seen in this photo from petemac110's post of several days ago:
Photo by petemac110
The cable on the right is attached to a jack that can be adjusted (inside the PSU) for any linear regulated DC voltage from 0.25V to 9.0V.
The cable on the left is a very well-made alternative to the uber-expensive KingRex uArt Y and uCraft Y cables (and others) that allow you to pull only power from one USB source (i.e. a 5V PSU like the TeraDak or a 5V battery pack) while pulling only data from another (i.e. your PC or laptop).
Open the spoiler to see Pete's photo of the back side of the cable on the left - into which you can plug another USB cable to provide data to the USB Type B connector that goes to your Concero (or any other USB-powered DAC).
I'm a recent convert to the Concero, having purchased the original model to replace my old audio-gd DAC3SE. I've included a photo showing the size/scale difference between these two DACs! The Concero is a great DAC, with a bit better detail retrieval than the DAC3SE, but not quite the same tonality. I rate it very highly indeed, especially given the incredibly small form-factor.
I'm using it with a Squeezebox Touch and I initially powered the Concero via the USB socket on the Touch. It seemed to perform fine, but the main downside for me was the need to physically unplug the USB socket from the DAC each time I wanted to switch it off. I leave my Touch powered on permanently, but in stand-by mode with the clock showing on the screen.
The cheapest 'decent' option that I found was the Teradak 9V PSU which now comes with a 5V USB output too. The PSU also includes a 5.5mm OD/2.1mm ID power cable, and a USB 'power-only' cable with data USB piggy-back capabilities (if that makes sense!). The cost was around $60 landed to Australia. I believe there is a slight improvement in bass definition and the noise floor with the Teradak PSU, but it's a closely-run race. It goes to show how decent the regulator stages are on the Concero!
Using the 'power-only' cable means that the Concero automatically reverts to SPDIF input mode, whereas when it was powered via the Touch, I needed to cycle through the input modes via the Apple remote as the Concero would revert to USB input mode each time.
One interesting point to note is that I tested the noise levels from this PSU, as well as a few switchmode USB PSUs including an Apple unit, and a generic unit.
The apple unit was around 80mV noise, and the generic unit was over 200mV! The Teradak noise levels were indistinguishable over background noise levels. I couldn't measure down to microvolt levels though. Sadly I didn't test the USB output of the SB Touch. I will do this in future.
Overall, I'm impressed with this power supply given the quality of the build, the included cables, and the very slight percieved improvement in sound quality. The addition of a switch to power the Concero up and down is also welcomed. :)
I want to add that I wouldn't recommend using an external power supply with the Concero to anyone who is not hearing at least occasional power-related glitches.
If this clutters up your desktop without improving the sound, why have it? It's much more convenient to supply both power and data to the Concero via a single cable. Don't fix what ain't broken.
In my case, as discussed several pages back, I've got a situation where my cheap laptop starts depriving the Concero of sufficient current (at least that's my hunch). Using an external power source fixes that infrequent problem.
Edited by zilch0md - 1/10/14 at 1:56pm