SMSL knocked it out of the park. The RAW-MDA1 sounds neutral and transparent. The sound isn’t colored nor completely analytical. Comparing it with the SU-1 DAC, the RAW has a wider soundstage with more transparency. I may see people not as fond of it because it might be too transparent without the special sauce. What’s special about it is delivering clarity without being too analytical. Maybe that’s its fingerprint. The word “neutral” gets tossed around so frequently that it becomes less meaningful and more of a cliche which I’m guilty of doing myself but this unit is the epitome of the term. Not only referencing tonality but the complete frequency range where nothing is particularly emphasized. The PCM filters and Sound Color are useful features that make a difference in the sound presentation.
The headphone amp has more than enough power (6x OPA1612A). I don’t own hard to drive planar headphones so I can’t speak on those circumstances but it drives my HD600 and IEMs with ease. My integrated amp has a headphone jack but the RAW has a much cleaner sound with a blacker background. Comparing it to the ONIX Alpha which some reviewers have stated it’s as good as desktop headphone amps, the RAW is more of a reference level unit compared to the Alpha dongle. The ONIX Alpha has a smoother sound with a more analog approach which I enjoy on a portable device when listening to music for hours with IEM’s. At home or at the shop I prefer the sound of the RAW. I tend to gravitate towards neutrality and transparency with no additives. Let the sound be manipulated by your choice of speakers or headphones/IEM.
Amplifiers like speakers can also be chosen based on a particular sound signature but you sacrifice some flexibility with correctly matching speakers or headphones. DAC’s shouldn’t have any influence in tonality other than to pass information at its purest form. The RAW does a great job at that. The headphone amp is strong and clear. The only nick picks I can point out is the RAW’s soundstage and depth could be more immersive. Also, it could have a more dynamic presentation. Perhaps have a more refined headphone amp but I can’t complain because it’s a solid unit that’s hard to beat for the price. You’ll have to spend at least double the price to reach pass those shortcomings. The RAW-MDA1 at $280 is a great bang for the buck.