FiiOK11 R2R DAC and Headphone Amplifier for Home Audio or PC, 6.35mm and Balanced 4.4mm, RCA, Coaxial, Optical, 1300mW, 384kHz/24Bit DSD256(Black)

There are a wide range of opinions out there about the sound quality of this DAC. I'm firmly in the "sounds excellent" camp, for DACs in this price range. Remember - this is an entry level DAC, not $5000 R2R DAC. It should be compared to other DACs in its price range, not to R2R DACs in general. That said, it has plenty of "R2R-ness" in how it sounds.The sound staging is excellent, about as good as you can get with headphones. The accuracy and precision is high enough that crappy recordings are nearly unbearable to listen to, as they should be. I played in orchestras and big bands and I'm always listening for inner parts - that third horn bit in this piece or the bass trombone part - and that's all there. I've gone back and forth on NOS versus oversampling, and find that just like on every other DAC I have, it depends which sounds best from album to album. I'm running it with a wifi Raspberry Pi supplying signal via USB.I have noticed that choosing the right sensitivity for the headphones used matters a LOT in sound quality, and I listen through everything from custom in-ears through some really nasty and hard to drive planar headphones. This DAC doesn't do a wonderful job on the two hardest to drive headphones, but is perfect for everything else as long as I pay attention to selecting the right sensitivity. But that means that each time I use a different headphone, I have to deal with that single knob interface. I find the single knob interface to be annoying and fussy like every other similar implementation out there... would a couple of selector buttons really kill the value proposition???Overall, happy with performance, sound quality. Fun to listen through. You'd be hard pressed to match the sound quality anywhere near this price

I've had 4 or 5 headphone DAC/Amps over the last several years. My most recent was a SMSL RAW-MDA 1. Really like that one a lot. But I have never tried a r2r before so decided to give this one a try since it falls right in my under $250 price range for items like this. Now after a month I can honestly say I can't see myself buying another desktop headphone amp/DAC combo. This sounds exactly like I like a DAC to sound. I am no means an audio file snob but I do like really good sounding music through my two channel system and my headphones. But I also like to find great budget finds that outperform their price point. I truly feel this is one of those items. I've never owned a Fiio product before but now I've been turned on to them I went ahead and bought their KA11 USBc to 3.5mm headphone dongle an love that too. As far as the sound quality goes of this r2r DAC Amp I really don't know how to describe it. It just sounds the way I like music to sound. All the other ones I've had sound great but this one sounds amazing. I think the r2r stage adds that secret sauce I've been missing in my headphone and iem sound. I've even tried tube based systems but I really didn't like those. The interface is pretty easy to learn and it doesn't have Bluetooth but I don't use Bluetooth unless I'm out mowing the lawn or doing something where cables could be dangerous or get in the way. Otherwise I'm a wired headphone/iem guy all the way. That's why that k11 dongle is such a great purchase for me, allows me to use my iem's a lot more often. If you have a desktop setup now but you feel it's been missing something, I would highly suggest giving this r2r a try. Both my sets of iems sound fantastic through this and all three of my headphones also.7

I use this to drive my Sennheiser HD600. With the DDHIFI TC28C Pro and the TC09S cable, I can use my iPhone or any DAP.- Compact/Low Profile- R2R DAC for the price is unbeatable

I tried quite a few DACs including some high end ones. I have 11-year old Denon DA-300USB that none of current DACs could even match (bifrost 2/64 would); until now - thanks to FiiO K11 R2R DAC.I find it intriguing when headphones are used to express sound stage observations - there is none whatsoever - it is all playing in your head - the sound stage is like 6-12" long. There is nothing to talk about it, really.Anyway, another intriguing findings is why other DACs failed to deliver sonic clarity, despite the excellent frequency response, low noise and distortion. I noticed that those DACs can deliver good quality to headphones users as channels do not interact - go straight to each ear. Different story with speakers, the channels do interact and if there is any phase shift at given frequency range (specially treble) - it can just cancel or reduce the final frequency response at the listening position - that would degrade experience severely. So those DACs do sound good in some compositions, but then fall apart in others. Neither my Denon, Schiit Bifrost have this issue, but many current DACs are making this mess. I am glad FiiO K11 R2R DAC is also free of this weird effects and delivers clean, slightly warm sound and good soundstage when used with speakers.Good job FiiO!PS: I noticed that with extended listening to FiiO I am getting fatigue and headache. I like elevated lows and highs in general, but in FiiO case - I was getting way more than I asked for. My advice - go to setup menu and change: OS (oversampling) to NOS (no over sampling). R2R are better without any oversampling. The sound will become more natural and neutral and you can listen to it for hours. It is still a little bit buggy, but not sound related: IDLE standby does not work, display shows signal sampling rate when there is no signal. I hope FiiO will address those bugs in the future. the LO (line out) mode makes very high voltage, well above 2V - it could cause clipping in some preamps, the only way is to switch to variable mode and reduce volume to ~96dB