Sound Impressions
Sonically the OS133 is quite v-shaped with an excited tuning that’s going to suit modern music. It isn’t dramatically powerful so I wouldn’t recommend it for headphones, but delivers ample volume with IEMs. Background noise levels are on the higher side by dongle standards, but not so loud as to be distracting during quiet passages of music.
The OS133 is quite bassy with sub bass in particular being satisfyingly elevated. Bass texture isn’t the most impressive I’ve heard but the extra quantity helps make up for it to generate a fun, bouncy sound that’ll suit modern Pop & EDM nicely.
Being a Penon product the midrange is fairly forward as you’d expect and decently engaging, definitely not recessed which is always a dealbreaker for me, though vocals can be a little dry at times.
Treble’s quite elevated, but could use more refinement. I don’t find it distracting but treble notes are a bit one-note & lacking the smoothness you get from expensive DAPs, but this is a $34 dongle after all.
Technical Performance
I find OS133 technical performance respectable for its’ extremely modest price & form factor, just don’t expect to be blown away here.
The soundstage is decently wide by dongle stands but doesn’t have much depth. Resolution’s better than expected from something so tiny, but lags well behind more expensive dongles & budget DAPs. It’s not so fuzzy that it becomes distracting though, and everything vital for musical enjoyment comes through.
There’s a bit of congestion particularly during busy passages when instruments can struggle to remain separated, you won’t get much reverb & decay on individual notes nor are they rendered with the delicacy of a decent DAP, but that’s no surprise either.
Dynamics are average which creates a smoother sound (which the v-shaped tuning helps ‘wake up’) and imaging is not the sharpest. Given the form factor I’m not sure how reasonable it’d be to expect more.
Page 1 – Introduction, Tech Specs & Ergonomics
Page 2 – Sound Impressions & Technical Performance
Page 3 – Dongle Comparisons
Page 4 – Conclusion
Not really understanding your comparisons. They don’t equate. And there are a few similar dongles using both chips for dac and amp. Common sense would be seeing how it compares to them. Not many are deicing between devices in vastly different price points.
That’s a good point you make Ryan.
Unfortunately Tail and the RU7 were the only other dongles I had at the time, but you’re right in that these aren’t really apples to apples comparisons given the respective price differences.
The OS133 is excellent value but I’m sure there are plenty of other dongle options out there which use similar hardware chips, it’s a very crowded marketplace these days!