HiBy FC6 USB Headphone R2R DAC/AMP with Darwin Architecture NOS/OS Mode (Black)

The Hiby FC6 is the closest I have found to a more recent Shanling M1 house sound (which Hiby made). The Shanling M1 is warm, pleasant, good treble but never too pronounced. Unfortunately, the M1 is getting on in years and now has: a short battery life; and less channel separation, noticeably lower fidelity sound than more recent offerings.The Hiby FC6 is warm, pleasant, has good separation, better clarity, and good treble though it can infrequently be too pronounced. It is incredibly small compared to everything else, the case is nice, the green finish is great, and it has some degree of volume memory. It does not do balanced so the output power isn't going to be what devices with balanced or their own batterys can do, and the case can shift such that it sticks the volume up button until caught. But overall it is very good and it is as close to the Shanling M1 as I have found in the dongles/portable dac space.What else did I try that did not get as close? Shanling UA5; Shanling H5; Shanling M0 (newer revision); Cayin RU6. Portably, not explicitly chasing this sound, I also have the Khadas Tea.In short: the UA5 has an interesting design and nice build quality but playback was lacking in the sub-bass and bass while the highs could get piercing (kept; for form factor, balanced out, and a modern Shanling point-of-comparison); the H5 was closer, a little warmer and more separation but far too neutral and orchestras didn't swell in the magnificent way the M1 does (returned; bulky, not the desired sound, much pricier); M0 has a terrible touchscreen UI, is a bit slow, the highs could get sharp, and also sounded too neutral (returned); the RU6 has very elevated bass and sub-bass in a pleasant way but the treble can get piercing depending on the speakers or headphones connected (kept; fun, pleasant sound even if it can get sharp or over-emphasize bass and sub-bass on some systems, example of Cayin sound). The Khadas Tea has emphasized bass in a fun way, good separation, and a convenient form factor (tall and thin, magsafe magnet for iOS and anything an aftermarket one can be applied to) but it's primary flaw is a very noticeable pulsing in the noise floor (depending on the playback device) which sounds battery-related.Ultimately, I have not found a higher fidelity 1:1 replacement for the Shanling M1. However, the Hiby FC6 is the closest I have come and its pretty good.

If you utilize streaming platforms and are in need of a convenient device to power your IEMs or headphones then I highly recommend the Hiby FC6!!! This dongle is not a powerhouse if you need to drive very high impedance headphones, but it did an admirable job with everything I tried, including my Sennheiser HD800s headphones which it drove to about 85% my normal listening volume without noticeable distortion.In regards to sound characteristics, this device is very liquid or analogue sounding. Tonally this device comes across as very neutral and there is no frequency that sounds emphasized. The attack or leading edge of notes as well as their decay come across as very natural sounding, almost as if you were listening to your digital tracks on vinyl instead and makes for easy listening for extended periods. Bass is punchy and has good texture, and the rest of the frequency response is smooth as silk. Vocals are intimate within a larger soundstage. Quality audio devices always have a way of evoking an emotional response and the FC6 does this effortlessly. The different filter settings don't make a tremendous difference to the overall sound, but they are fun to play with. Keep in mind that the filters don't change while in NOS mode. I hope that in the future that they will consider creating a device that has a 4.4mm balanced output. But I easily got around this by using an adapter.Comparisons:-Fiio BTR7: The BTR7 is a more powerful device and is slightly more punchy in regards to bass. The FC6 sounds more rich and natural by comparison and I find myself reaching for the FC6 far more often.-Aune Yuki: The Yuki is also more powerful and sports a 4.4mm output which is convenient. The Yuki sounds brighter overall and there is a really great sense of texture to the sound. Small details like the huskiness of some vocals or wood instruments are more apparent on the Yuki. By comparison the FC6 again sounds more rich and warmer. The FC6 also has a more intimate presentation without feeling claustrophobic. For my personal taste and the based on the music I prefer (indie rock, jazz, instrumentals) I prefer the FC6.Devices I Tested:-Dunu SA6 Mk2 (my favorite companion to the FC6)-Aful MagicOne-Ikko OH-10-Koss KPH40-Grado Hemps-Sennheiser HD600-Sennheiser HD800S (not a suitable replacement for a desktop amp)