With all the talk about how these are good, I got them myself to check them out since they're only $8, and could really use a clean source for my FLC8S anyways.

I am reviewing the US version with 1V out at full volume. The EU version apparently has worse SNR and power (voltage is half of US version). RIP EU people.

Excuse my 'adaptor' spelling, blame spellcheck.

Setup

Source:

• XPS 15

• Galaxy S8

DAC/AMP Mentioned in This Review:

• Apple USB-C to 3.5mm

• EarStudio ES100

• XPS 15 internal chipset

Gear

• FLC8S (11 ohm)

• Etymotic ER3XR (22 ohm)

• Etymotic ER3XR + 75 ohm impedance adaptor

• HD 6XX

The main sound test is done on my XPS 15 (Win 10). The S8 is just there to test out Android volume problems.

Relevant Measurements

Reference Audio Analyzer (EU A2155 version):

Output Impedance: 0.32 ohm

Audio Science (US A2049 version):

1.039 Vrms, 98dB SINAD

Output Impedance: 0.9 ohm

XPS 15 (Windows 10)

On Windows 10, there are 4 audio modes supported: 16/24 bit, and 44.1/48 kHz. 24 bit is neat for those who are anal about their bits. (The dongle is 98dB SINAD which is ≈16 bit resolution. The dongle has digital volume control. Windows 10 volume at 2/100 is -34dB attenuation, thus at 24bit mode you essentially still have ≈18 bit resolution??? IDK.)

One weird (but intended) behavior if you're used to conventional DACs is that without headphones plugged in the Apple dongle will disable itself. I though mine was defective until I remembered that it is an Apple product and is probably idiot proofed that way.

Impressions

Note: A lot of my word choices are exaggerated to emphasize the difference. If you are new to this hobby, you'd be surprised how small the difference is. Budget conscious people should understand that headphones make a greater difference than your DAC/AMP does as long as it is not complete garbage.

The Apple USB-C to 3.5mm adaptor (henceforth referred as the Apple dongle) is really quiet (low noise floor). I don't hear any hiss with my FLC8S, which is a really good thing. For comparison, my FLCs can hear CPU/GPU buzzing noises on my iPad, a constant white noise floor on my S8, and a loud hiss on my XPS 15 (unusable).

For my FLC8S, Windows is about 2-6% volume level. The dongle is very clean, and powered it very well. If you have a sensitive IEM and want to use it on a Windows laptop, the Apple dongle in probably the best cheap solution. I have a hard time imagining anything beating it save for the higher end DAPs.

Similar story for my ER3XR, although I can't hear CPU/GPU noises on my iPad, and my XPS 15 noise floor is low enough to be tolerable. Volume level is about 6-12%.

Now the Etys with the 75 ohm impedance adaptor is where it gets interesting. The sub-bass is weaker (due to impedance adaptor), but it is slightly weaker than it should be compared to the ES100. Instead of a quick and clean bass, it lacks a bit energy. We can see that about this point is where the Apple dongle is reaching its limit despite volume level is still at 20-30%.

The HD 6XX, while still surprisingly listenable, is where the dongle begins to show its struggle. The dongle seems to have a bit more distortion in the highs (a bit "harsh/bright"), highs are still better than XPS internal headphone jack with slightly more dynamics and sounding more clean. Bass impact is muddy/soft compared to EarStudio. Windows volume is in the 30s to 50s range (huge variation due to open back). The EarStudio had most dynamics, especially bass drum, toms and timpani actually felt real with impact.

Technically speaking, the Earstudio still isn't powerful enough for my HD6XX. Before I sold my Topping DX3Pro I briefly compared it to my Earstudio, and found it to be slightly better. Don't remember how exactly slightly better though, as I didn't write any notes, but I do remember coming to the conclusion that they sounded very similar but the DX3Pro is slightly better.

S8

There seems to be some audio issues in Android where the volume level is set incorrectly for dongles. Apparently if you have a rooted phone, simply editing a file is enough to fix this issue. Impressions are identical to that on my PC, with the exception of volume problems.

6XX: Internal headphone jack 46% volume, dongle 100% volume. 93% is too quiet, 100% suddenly gets a bit too loud.

FLC8S: Internal headphone jack 33% volume, dongle 67%.

ER3XR: Internal headphone jack 40% volume, dongle 87%.

A lot of people claim the dongle is unusable on Android, and to an extent... is true? However, for sensitive IEMs, I see no problem with the dongle unless you're stuck with the EU version, in which case, RIP.

Conclusion - Should I get it?

If you have an iPhone and need a dongle, yes. If you own a Macbook, hell no. If you own an Android phone, maybe...? It's $8 dollars only, so your wallet shouldn't cry even if it doesn't work well.

Now here's the more interesting uses: Using it on a PC with USB C (as many PC internal chipset design sucks, especially for IEMs), and using it as a cheap "DAC" for your AMP in a budget setup.

The former is self explanatory. You have an IEM and your device has terrible noise. Just grab this dongle and call it a day, simple as that. Heck even if you needed to drive headphones, these are perfectly fine as a cheap solution.

Now the latter is a more interesting way to use this dongle. Let's say you blew most your budget on a brand new 300 ohm headphone, you're short on $$$, and your motherboard audio sucks. You could grab something like the JDS Atom, and use this Apple dongle as your budget "DAC" until you can upgrade to a proper standalone one, with the only down side being that its max output is 1 Vrms (-6db to standard 2 Vrms, basically 1/4 quieter).

Some measurements comparing the device: Note: Beware that the Apple dongle is a combined unit (DAC/AMP), and may or may not be directly comparable to the units listed. Values from AudioScience.

Takeaway: Assuming you don't push the Apple dongle into distortion territory, it performs amazingly well, comparable to many $100 devices. For any headphone <50 ohms, the Apple dongle will probably work perfectly for most people.

The only real problem with this dongle other than its power is the build quality. The cable is super thin and not very confidence inspiring. Those confident in DIYing, you could try re-cabling it. I might wrap the cable with Kapton tape and heat shrink in the future.