Performance Testing

The EarMen Sparrow uses the flagship ESS Sabre ES9281PRO portable SoC, which is rated at lower distortion and higher processing power than the ES9218P used in the less-expensive FiiO BTR5. It provides "best-in-class audio performance at 124 dB DNR and -112 Total Harmonic Distortion plus Noise (THD+N)." While a small improvement over the ES9218P, where it distinguishes itself further is by being the first USB product that offers an integrated hardware MQA renderer. This makes native MQA playback on the EarMen Sparrow possible, which only a handful of portable devices are capable of.

If you are not familiar with how MQA works, it is a lossy compression algorithm that has an encoding process "fold" extra information into the compressed signal that can be "unfolded" at the output to get back the native signal prior to compression—or so the claim goes anyway. I am not going to debate how good or bad MQA is at all the things claimed, but if you value it, you will be glad to know that the ES9281PRO automatically detects the MQA stream and engages the rendering. The entire process requires no extra effort on behalf of EarMen, which can irk some who think the company took a shortcut by using a single chipset to handle everything, but this is also efficient engineering and design in my books.

As it turns out, the EarMen Sparrow supports Tidal Masters (MQA) playback on PC, Android, and iOS devices to theoretically allow high-resolution files to be transmitted as smaller files for easier music streaming on the go. On the output, the EarMen Sparrow's MQA renderer completes the unfolding process on the device before passing it on to the connected headphones. If Tidal isn't your jam, the Sparrow also supports Qobuz's high-resolution streaming playback on Windows/macOS/Android/iOS, which in turn provides streaming and local storage of FLAC files at up to 24-bit/192 kHz. I tried both Tidal and Qubuz, in addition to Amazon Music HD, and it was funny to see the LED go green-magenta-green-white over the course of testing. I also have a lot of local files on my phone to begin with, so that is how most of the testing was done, since portable DAC/amps such as the EarMen Sparrow are really not going to be used much on a desktop or laptop.

Let's talk power, shall we? Given the mismatching numbers we spoke about earlier, I am going with those reported in the user manual—they are also more detailed than on the product page. But in practice, it barely matters since the practical use cases will be earphones and headphones that are relatively easy to drive. On the 3.5 mm output, which no doubt many users will adopt, the EarMen Sparrow can output 1.4 Vrms at a 32 Ω load with THD+N <0.004%. This corresponds to 61.25 mW and is lower than the 80 mW from the dual-DAC setup on the FiiO BTR5 (even in wireless mode). The same 32 Ω load can have ~107 mW on the 2.5 mm balanced output, which of course can provide more power across the two channels. This too is lower than on the FiiO BTR5 with its ~245 mW output under similar conditions, and by a significant margin at that. FiiO does not rate the BTR5 with higher impedance loads, which EarMen does.

But I suspect the story will be similar in that regard, to where the Sparrow will be good for pretty much all practical use cases, but does not afford you more headroom once you move to headphones that are harder to drive. In practice, this was a non-issue. If anything, the ES9281PRO allows for excellent playback without distortion even at the highest of volumes from your phone/PC. I really had no issues with the playback on devices I know the sound of, and they do perform as they should with the EarMen Sparrow, especially on the balanced output. While it might be the "Super LOW ESR tantal capacitors," 4-layer gold-plated PCB, or the other "high grade components" used in the power supply stage, it all makes for an extremely impressive plug-and-play setup in a tiny form factor. This is all I want the Sparrow to do, and in that regard, it is job well done.


To better illustrate my point, I have randomly chosen a set of high-end IEMs with balanced and single-ended cables to pair with the EarMen Sparrow and my laptop. Testing was done similar to any other IEMs, which you can read up on in an example review. The earphones used here are extremely well tuned to begin with, with lots of active cross-over, too. It helps easily discern any output/drive issues, and I know exactly how it should sound on my reference soundcard as well. The two graphs above first compare the output from the 3.5 mm and 2.5 mm balanced outputs on the EarMen Sparrow, which in turn was connected to my laptop. There are no first-party ASIO USB drivers, so choosing the EarMen Sparrow USB device as the output is all you can really do in addition to player-specific tuning/EQ. There are obvious improvements in comparison to the laptop's own Realtek ALC3266 chipset throughout the frequency range. Gone is the boosted bass that loses clarity on a whim, whatever that mids response is with poor imaging and soundstage, and gone also is thankfully the ridiculously bad treble roll-off that makes my ears ring at times. The EarMen Sparrow cleans it all up and provides for a fantastic listening experience. Note that the 3.5 mm output does have a slightly boosted mid-bass at the loss of some range in the mids, and this is also why I preferred the 2.5 mm output, which was truer to design. This difference is even more obvious when comparing the 3.5 mm output on the Sparrow to the 3.5 mm output on my reference soundcard, with a further boosted bass and sub-bass alike. There is also slightly more variability in the highs with the Sparrow, but those could be measurement artifacts since I did not really perceive it in my own listening.

What this means is that the 3.5 mm output can potentially add some warmth to the bass response of your IEMs or headphones, so keep that in mind if a pro or con to you. For highly neutral devices, such as the Audeze Euclid or Etymotic Evo, this can help cut down the shock when going from typical V-shaped tuned headphones to more monitor-style devices. At the same time, the 2.5 mm output is truer to the actual signal and also provides more power. I personally would use it far more, but also lament it being used over 4.4 mm knowing that the 2.5 mm output is quite uncommon and getting more uncommon daily. It does mean that the Sparrow will sip more battery from your phone, and the USB Type-C port without a passthrough results in the inability to charge the phone at the same time. I will also mention that I do not have a 5G-compatible device at this time, so I can't say if that affects any of the signal integrity or causes interference. The newer cables coupled with my laptop and 4G LTE phone have not had any hissing or drop-outs with the EarMen Sparrow, so those in the past reported issues are not something I can really talk about.