iFiZen Air DAC - High Resolution DAC - MQA Renderer - High Resolution Music DAC

Any of these are going to greatly improve the sound over plugging your headphones directly into the mini-jack on a computer.Listening was done with a few different headphones but mostly with beyerdynamic DT 700 PRO X Closed-Back Studio Headphones. Music source was a laptop connected to the DAC/Headphone Amp via USB. If an external power supply was included, I used that. If not, power came via USB.I've kept notes on my impressions brief and included comparisons amongst the DAC/Amp's in this list. They are listed below in my order of preference with my favorites at the top. If you want flowery vocabulary I'm sure in depth reviews are available out there on the web.Headphones make the greatest difference in sound - spend more on them, if necessary. The DAC/Amp is secondary but does add its own flavor to the music.---iFi Zen DAC V2 | Desktop Digital Analog Converter(Listening only with "TRUEBASS" off.)Very good.Slightly better than the FiiO K7. Better vocal clarity and slightly fuller bass.I ended up comparing this with the FX-Audio DAC-X6 head to head, which continued to surprise me as I put it up against significantly more expensive competitors. Across several hours and many pieces of music, I prefer the iFi... but the difference is infinitesimal. Possibly the iFi has a little more punch to the bass? Maybe a bit more space ans separation? If you're working to a budget, get the FX-Audio and put the extra cash towards better headphones.FX-Audio DAC-X6 Mini HiFi 2.0 Digital Audio Decoder DACThis thing is good. Surprisingly good. I ended up putting it head-to-head with amps costing three times its price.Slightly warmer sound, with slightly less detail in the vocals than the iFi Zen Air, but more space in the music, and more enjoyable to listen to. Slightly better clarity than the Topping.FiiO K7 Full Balanced HiFi DAC Headphone AmplifierThis is indeed better than the K5 version. Vocals are more lifelike. And a particular emphasis on the mid-treble heard in the K5 is absent. There is more separation between the instruments.Very close call with the iFi V2, with my preference going to the iFi for better vocal clarity and slightly fuller bass.iFi Zen Air DACNot quite as good as the V2, but close. Closer than the FiiO K5 is to the K7. There is, again, a comparative emphasis in mid-treble and the vocals get a bit lost. The sound is slightly thin compared to rivals at this price point.FiiO K5 Pro Headphone Amps Portable Desktop DAC and AmplifierNot quite as good as the K7, but at half the price one cannot really complain. Vocals are not quite as lifelike and there is more mid-treble - but not in a good way.Topping DX1 Mini Stereo DAC Headphone Amplifier ComboVery good little unit. Bass is slightly overemphasized.Fosi Audio K5 Pro Gaming DAC Headphone AmplifierI thought this unit was DOA. Turns out that you must long press the volume knob to turn it on. (Short press to select input.)Not terrible, but not as musical as the others in this test. Also, the only one with bass and treble knobs. And only a mini-jack - no 1/4" jack.Pro-Ject Head Box S2 DigitalThis DAC/Amp had an issue that makes it unlistenable. The sound is very nice... but... there's some faint static. Only in the music, not in silence. A faint crackling.... Can't have that.

Finally, the mystery of 11 year old and unbeatable, until now, Denon DA-300USB is solved - it was Burr Brown DAC chip. ZEN Air DAC has very natural and clean sound thanks to Burr Brow True Native MultiBit DAC chip.A few notes about line out RCA:- The volume(voltage) is very low by default - you need to enable PowerMatch mode to get voltage on line out > 2V (with in specs).- Analog type variable volume is aways on, but it does not matter really, also you can use it as pre-amp when needed.- The XBass+ is available on line out as well, so you can boost bass on old recordings that are often lack bass.The only small con: the RCA jacks are a bit on the loose side.

Pros - Great sound when powered by a 5V source. Small. Easy to hook up. Firmware updates including digital filter updates! MQA decoding at entry level price.Cons - Avg to Below Avg sound when powered by USB only. Weak headphone amp, only good for sensitive or easy to drive headphones. Misleading, confusing documentation for 5V power source.* Unable to control audio levels via operating system (volume, balance, etc).** Missing balance control knob on the DAC. Lots of plastic.Overall take away - Fantastic sound (when powered with a separate 5V source), with a hint of inner warmth - might be what you need for system synergy. The plastic does feel a bit cheap, but the deal breaker for me was the inability to change the audio balance left/right without installing some third party application. IfI should have added a balance control knob. If you need MQA decoding, definitely consider!* - Some documentation says 5V/0.5A while some says 5V/2.5A. I think the actual number is 5V/0.5A as I was able to power it perfectly fine with 5V/1.8A. I had a typical USB power supply on hand for a phone/tablet (9 Watts, 5V/1.8A) and picked up a USB to 5V DC barrel cord to connect it. Furthermore, the specs say it only consumes 2.5W maximum. IfI probably has it specified this way to get you to buy their very expensive linear PSU which is 5V/2.5A.** - You can download some third party software that will give you control of the audio levels from the OS.

The way this dac/amp powers the monstrously large drivers and doesn’t sacrifice on audio fidelity is next to none. Even though the AKG K712 pros are super old at this point, they completely blow cans that see even $1000 or higher out of the water.Try to pair this DAC to K712s and use a music streaming platform like amazon music. they have the largest catalogue of lossless music and i’m an extreme audiophile. I literally have no use for the $20,000+ i’ve spent over the last year on “impeccable” audiophile grade IEMs or overhead cans. the K712s may not look like the sleekest headset but make no mistake.You don’t even feel them on your head they’re that comfortable. Just make sure you press the boost button on the DAC or it won’t sound like the drivers are being powered fully. NOT THE BASS BOOST BUTTON. I couldn’t rate this audio pair higher. It’s a cheap DAC that gets the job done flawlessly with the highest audio fidelity you will ever hear for $500. Seriously.If you buy this DAC, try them either the K712pros. I guarantee you will be blown away like I have.