Apogee GROOVE - Portable USB Headphone Amp and DAC, Bus Powered for Mac and PC, Made in USA

tl:dr: The Apogee Groove is the Real Deal.The Groove is a deceptively simple portable DAC & headphone amplifier, that delivers breathtakingly high quality audio into the right headphones (see below) for such a small device. Its target market is professional audio engineers who need a trustworthy and neutral-sounding playback source when away from their studio, but it also delivers the goods - at a sensible price - for audiophiles too.The Groove is a plain black minimalist rectangle of aluminium, with just a single micro-USB input and a 3.5mm stereo jack out. It has two rubber-covered buttons for volume control, which allow for finer control than you might expect. There's also a column of 3 LEDs that shows audio levels. This might not seem like much, but they're cleverly designed - they light purple to show the playback volume you're setting via the buttons, and green to show playback level. The green LEDs show different brightness according to level, which again deliver more information than you might expect. If the source input level is pushing the Groove close to clipping, the top-most green LED flashes red to remind you to drop the input level a bit.In keeping with the Groove's simplicity, it ships with just a fabric storage pouch and two USB cables (A- & C-terminated respectively). If you're using it with Windows you'll need to download the driver from Apogee's website - apparently Macs don't need a driver. The Windows driver supports both WASAPI and ASIO audio architectures. Please note that the Groove is a power-hungry little thing (it gets quite warm during use), so won't work with phones or tablets.Sound-wise the Groove seriously exceeds expectations at this price. I won't blather on with the usual audiophile subjective comments, other than to say that it's as transparent, neutral and revealing as one could possibly wish for. It's fundamentally trustworthy, and if you're looking for a step up from this you'll probably need to spend ten times its price.An important caveat: in keeping with its professional audio roots the Groove is at its best when driving higher-impedance headphones - Apogee recommends Sennheiser's HD 800, HD 650 (as used by your humble scribe), or Momentum. If you have a pair of these then you're in for a treat.

Bought as an interface out of a Mac instead of the standard output, vast improvement.

I have a pair of AKG712 Pro headphones and needed a headphone amp/DAC to power them. I was a little nervous about buying the Groove as I couldn't find any reviews about this unit anywhere online, also it isn't mains powered (USB only), so I was concerned that it wouldn't be able to power the 712's sufficiently. I have previously owned a Duet 2, so I was hoping the Groove would also deliver the same level of quality. When I received it, I certainly didn't feel let down and was pleasantly surprised by the build and sound quality. I would say that the Groove sounds slightly better than the Duet 2 through the headphones. It is clear, consistent and incredibly detailed, you couldn't ask for any better performance at this price. There is absolutely no system noise seeping through this unit, it's dead silent. There's also enough volume despite it lacking mains power; I wouldn't say there was an abundance of power, but there's easily enough to get the volume you desire with a some headroom to spare. If you want it any louder you may have something wrong with your hearing - I would suggest going to an ear specialist! For info, I'm using the Groove on my Mac Mini, so it's always mains powered, I haven't tried it out on a laptop as yet, so I'm not sure if the Groove performance would be impacted on battery power only. I did test the Groove on a PC tower and it performed equally as good as on my Mac, it was also just as easy to configure on both Mac and PC.

Great sounding, runs a little hot for my taste, though wish I'd waited and bought the Chord Mojo, which sounds better and can be used without a PC

The Apogee is a very capable piece of kit. It’s small form factor lends itself to portable devices, but doesn’t completely remove itself from Desktop suitability.3 Things I Loved:1) The Weight and quality of the Groove is great, it feels expensive2) The LED lighting system is simple but effective in communicating volume adjusts and sound3) It works! My 660S’s work brilliantly with this device3 Things I’m Questioning1) The UK price seems extremely heavy.2) It gets very warm/hot. This is normal under the power it delivers...but jeez this gets hot.3) The USB cable is really short, not ideal for Desktop use. Easily resolved with a micro usb to usb purchase.