Thoughts on the 'Portable Shootout' today:
Disclaimer: using the solid Titan mesh & hybrid pads
Woo Audio Tube Mini: this thing is obviously legendary for the ridiculous gobs of power it has for a dongle. Woo are serious magicians for squeezing such power into such a small device. There are trade offs (i.e. ringing/not for portable use/doesn't really work with IEMs) but it absolutely powers the Bokeh to the brink. I barely got it above 25% on Roon ARC off of my iPad before it was a bit too loud. Sound wise, this really emphasizes the Bokeh's sound signature. The mids were the star of the show, with slightly smoother bass (wouldn't say less punchy, but definitely a teeny bit more rolled off than on non-tube) and a crisp, sparkling highs. The Tube Mini seemed to really push the treble on the Bokeh a bit further than the other two I played with today, so there was a bit more of a sparkling...crunch? Sibilance? The highs are still very much there. I thought they maybe could've been a teeny bit too bright, but not a deal breaker. Soundstage was the same across the board for all three. I felt like the Bokeh + Tube Mini was a better mix for the dreamier stuff I was playing on it, such as Talk Talk's Spirit of Life and Radiohead's Kid A. The highs got a little in-your-face on Liturgy and Mayhem. This amp does have a pretty specific sound signature, so YMMV. I'm not here for balanced audio, so the Woo is always a favorite for pure sound in a small package, but with a handful of trade offs.
Cayin RU7: this was exactly what I want out of a dongle. Less power than the Woo, but obviously much less power. Very much like the Cayin house sound, everything is very balanced, smack dab neutral, with just a tiny touch of warmness. I feel like there is a bit of bass roll off with it, but nothing over the top. The high end performed best on this as well, I noticed none of the almost-Grado-like aggressiveness as I did with the Woo. The mids are a little bit more recessed, but overall this feels so natural and tuned spectacularly. Best dongle I have tried, honestly. This one did well on all my test albums, but I felt like the Cayin really shined with some of the heavier metal such as Mayhem's De Mysteriis Dom Sathanas and Wolves in the Throne Room. It does well on the moodier stuff, but I think the Woo's really aggressive sound signature helps you lose yourself in the sound. This is really a spectacular IEM dongle, as you do have to push it a bit to get it to a louder volume. Played off of my iPad, tried off of the iPhone.
Astell&Kern SP3000: personally, I find this guy as the ultimate IEM machine. You have to really get to a very loud volume (110+) to get loud enough sound off of it for most over ear headphones. BUT, this is probably the most lush, detailed portable setup you're going to find on the Bokeh. This thing lends itself to a neutralness you just don't find often. As you get a bit higher in the volume range, you can really sense the headroom start to condense though, and it did feel like it had less of a soundstage than the others, almost a bit claustrophobic. However, there wasn't the rolloff or recession of the RU7, and the slightly sharp Woo high was nowhere to be found, without that aggressiveness. It is incredibly normal. I think the Bokeh shines on the SP3000 despite the condensed soundstage, you can really grasp the intense mid-bass on these, some of the stuff I was listening to like Radiohead's Kid A had an absurd amount of punch. The SP3000's speed and attention to detail (you really can not feed it anything too fast or intense, it will always excel) was huge on stuff like Liturgy, but the punch of the bass and smooth high end REALLY showed off on stuff like Black Sabbath and Sleep. Obviously the cost is lolworthy but it's still a monster DAP.
I think all 3 have their strengths. The Woo isn't really portable and is really just a desk MONSTER and has the most out-there and best but flavored sound of all three, but the Bokeh is a spectacular headphone on really all 3 of these. I think it's pretty cool how I haven't fed the Bokeh to an amp that they don't sound amazing on, with all 3 having some slightly different quirks. Anyway. Just some thoughts. The RU7 is pretty sweet for a small dongle for the Bokeh, so if you want portability from these, that's probably your best bet.