This Cirrus CS43131 based DAC/ Amp "dongle" combo is a little wonder. I decided to give it a try after reading the positive review on Audio Science Review. I was on the lookout to replace my aging FiiO Alpen portable DAC and this appeared to be the perfect replacement.
It is has a diminutive size and no rechargeable battery which makes it light and eminently portable. It does take power from the unit it is hooked on but the drain is not all that bad especially if used with efficient headphones, especially IEMs. External volume controls and an additional (unheard at this price) balanced headphone out add incredible value to an already fully featured unit.
For actual measurements and all that jazz you can refer to the extensive set performed by Audio Science Review. Long story short for the TL:DR people, the measured performance is exceptional, rivaling good desktop/ dedicated DACs/ Amps, featuring low noise/ distortion/ jitter, high linearity/ dynamic range, great filtering and very decent distortion free output power (43mW into 300 Ohm load and 172mW into 33 Ohm load).
I tested this unit hooked up to my iPhone 13 Mini, iPad Air 6 (M2) and to my PC Workstation, running iTunes/ Apple Music/ Foobar2000/ JRiver MC33. The headphones tested with it were: HiFiMan HE400i and RE-400, PSB M4U, Beyer DT240 Pro, Final E-4000, Moondrop CHU II. I am very familiar with these headphones, I used some of them for years hooked up to some pretty decent pieces of gear in my possession, such as Accuphase and NAD preamps, Arcam, Denon, Rotel, Topping or SMSL DACs and my Nak, Oracle analog front ends.
Now, with the name dropping aside, I will touch briefly onto the sound of this unit.
This diminutive DAC/Amp had no problem driving any of the above mentioned headphones, including the HE400i, whose planar design is generally posing a challenge to portable gear. The Fosi DS2 handled everything with poise and grace, without any hint of distortion or clipping.
As for the "sound" itself... well it sounds like nothing, as it should. The Fosi DS2 has no "character" of its own so does neither add nor subtract anything from the signal it is being fed. Similarly with any true high resolution/ high fidelity playback unit, the music comes thru clear and uncoloured, faithfully representing the recording or the material being played. I like using a FLAC version of the Triangle CD Demo, which has pretty much everything you want in terms of sound, from closed miked voices and instruments to large orchestral ensembles, from intimate jazz tunes to big dynamic swinging symphonic pieces or glass shattering, garage door banging sounds. This recording, along Pink Floyd's DSOTM and Mike Oldfield's Tubular Bells II are the ones I'm typically relying upon in this kind of subjective testing.
There isn't a hint of harshness, sibilance, bloom or any of those things professional gear reviewers sometimes use to describe what they hear. The Fosi DS2 would leave these reviewers with almost nothing to say really, its musical performance reflects closely the unit’s exemplary, almost textbook perfect bench performance.
100% recommended, this diminutive DAC/ Amp unit punches way above its weight. It matches or it exceeds performance at almost any price level.
| Manufacturer | Fosi Audio |
|---|---|
| Place of Business | Fosi Audio |
| Item model number | DS2 |
| Product Dimensions | 5.51 x 1.91 x 1.19 cm; 54.43 g |
| ASIN | B0CTHN2QB3 |
