So I got the Lotoo S1 yesterday and just received the iFi Hip DAC about an hour ago. I have been A/B'ing the two units for about half an hour now with my pair of Final Audio B3 IEM's which are a relatively neutral set of IEM's out of the 4.4 balanced output on both DAC's.
My initial impressions of the Lotoo S1 is that it is very neutral sounding in general and definitely seems more reference in its presentation. There is no emphasis on any region of the sound signature and everything is presented as is according to the music. I have heard from others who have posted on this thread previously that the "dental" EQ setting improved on the detail presentation of the S1 which I also found to be true. The dental EQ does make the S1 sound a little but more clear and airy in its presentation. The S1 is very clean sounding and I would recommend the S1 for those that are looking for a cleaner/reference sound. Some things I felt the S1 was a little lacking in was how it affected instrument decay and soundstage. However, I believe this is due to do with the power output of the S1 more than anything. My Final B3's are relatively inefficient when it comes to the power needed. The 120 mW power output out of the balanced connection on the S1 does seems a little inadequate for my Final B3's. With insufficient power, my IEM's exhibit a smaller soundstage. Through the S1, the soundstage was smaller and this lead to music being more "in your face" from the instruments to the vocals. Some might like this presentation, but for me personally I wished there was more space in the soundstage. Instrument decay seemed to be a little shorter than on the iFi Hip DAC.
Moving on to the iFi Hip DAC, my initial impressions after about 30 minutes of use is very different to that of the S1. I would describe the Hip DAC (in comparison to the S1) to be more lush/warm in its sound delivery with more bass presence and vocal forwardness. The mid bass is more present than on the S1 which has a more linear approach to each region of the sound frequency response. I also noticed that vocals are more forward and seem to float above the instruments ever so slightly, and sounded fuller and more lush whereas the S1 vocals sounded a little more thin/crisp in comparison. The vocals also have a more shimmery presentation/decay when compared to the S1. The soundstage on the Hip DAC is definitely more wide than compared to the S1 with more width (the instruments and vocals are a little further out). To me personally, this lead to the sensation of more space between each instrument and the vocals, which gave the impression of a less "in your face" presentation. I think this increase in soundstage is due to the higher power output of the balanced output of the Hip DAC (400 mW compared to the 120 mW of the S1). I also tried out the xBass function of the Hip DAC and found that it does elevate the bass region in a tasteful way, but it does sometimes bleed into the midrange, causing the vocals to become a little muddy when compared to the xBass being off. Also as a side note, the iFi Hip DAC on high gain out of the balanced 4.4 output did have some audible background noise.
Please keep in mind these are impressions from a very short period of use and these are just things that stood out to me initially. But as of right now, I personally am leaning towards the Hip DAC due to its wider soundstage presentation and warmer/lusher sound when compared to the S1. Since my IEM's are relatively neutral with a sub-bass rolloff, the warmth added by the Hip DAC is enjoyable to listen to. The Hip DAC definitely provides a more relaxed listening experience whereas the S1 is definitely more neutral and reference. I appreciate how clean sounding the S1 is in general and would recommend it to those looking for a brighter/more neutral sound or for those with warmer gear and want to have a very portable AMP/DAC dongle that does not color the sound and instead takes a step back, allowing the gear to shine through. The Hip DAC I would recommend to those that are looking for a warmer, more lush, more musical, and more relaxing experience. I think if you already have warm sounding headphones/IEM's the Hip DAC would color the sound a little too much imo, but if you have neutral/bright equipment and you are looking to add some warmth, the Hip DAC is perfect for you. Also if you have harder to drive equipment that needs more power, I would recommend the Hip DAC over the S1. If it is portability you are after, the S1 wins hands down. This wraps up my thoughts for now and feel free to ask questions.
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maybe M6 didn't have enough juice.
