The DAC is outstanding in terms of sound. I consider it slightly better than the Sony DAP ZX300. It is not day and night differences, but audible if the UDA38Pro is fed with a good source. For that, I noticed that it should be fed with a 9-12V power source. I was using a battery pack that has 12v out, and I find that the soundstage deepens and widens as compared to a 5V LPS. I am still playing with various options, but it seems that the DAC is quite immune to jitter and a iPurifier2 did not drastically improve the sound quality. I also feel that the USB input is better than the optical. But I only have one player with optical out, so I cannot be sure. I would like to see coaxial on the DAC, but I can't complain for the price. Overall, I am enjoying this DAC immensely through a PS Audio LANRover like device to achieve galvanic isolation, and I feel that this is the most important enhancement (together with using a higher voltage power supply) if I were to rank.
Having owned the HIFIME TYPE C USB DAC (ES9018K2M+SA9023), I knew I would not be disappointed with Hifime's products. However, I do have to say the UDA38Pro really impressed me. Personally I prefer the sound signature of Sabre dacs, especially the 9018 ones. Being used to my RL Concero and W4S Dac-1, the UDA38Pro surprised me with how natural and transparent DSD tracks sounded through my DT880 250ohm. At this price point, buying it is a no brainer if you appreciate the performance of Sabre dacs. I currently run it through the iFi iDefender with iPower, and prefer my set ups with it (more power and better resolution I feel?).
For the beginning, I checked it with Crossfade LP2 headphones, and I imediatelly noticed wider soundstage comparing to 9018 based dac I used before (same range price, Apogee Groove), however I lost the bass power that Groove provided and I could not live without it. :)
I checked it later with my Stax combo, and started to appreciate more in this combination. The overall transparency and detail was a pleasure to listen to, for good recordings.
The only thing that I miss from my previous 9018 based dac used for Stax, was the... power button. :( It would be great to have a way to turn off all the lights when not in use.
Adding separate power supply did not improve noticeable the sound in my case. The bass was still shy, but that is not a big problem since I will use them with Stax.
The UDA38Pro exceeded my expectations. Having heard MANY dacs in the sub $500 range over the years, I was initially skeptical of the performance capable of an ES9038Pro based unit at such a low price. I was pleasantly surprised to find this dac to not have the typical Sabre sound of cheaper dacs. This dac is more three dimensional with a beautiful midrange. Make sure to give it the best quality power supply possible and you will be rewarded.
A very technically capable DAC - neutral, smooth, realistic texture and detail. It has a sweet and liquidic character, an extremely pleasant and addictive sound. For me it is close to perfect.
I can only compare to the Audio-GD R2R11 DAC and I think the UDA38 Pro is superior. The R2R11 had an unnatural coarseness to the sound, lacking in fine detail and sounding smeared with more complex music.
the lossless volume works very well, there is no quality loss at any level. as mentioned by another reviewer it doesnt get very loud till about halfway, its a very steep logarithmic curve.