Best USB-C to Audio Jack Adapter for FP4

I Had a similar issue and it turned out to be the headphones, have you tried with another headphones?

I would strongly suspect, given the size of that adapter, that it is not actually a USB-C to analog audio adapter, but is instead using audio adapter accessory mode. If that’s the case, then it won’t actually work with many, possibly most, phones, including the FP4. It’s really unfortunate that this mode was both created and not required: USB-C would arguably be better, and certainly less at risk of not working, if the mode didn’t exist, or if it was required for devices supporting audio.

On the other hand, it is arguably also the fault of the vendor for not describing the item properly. If you do an image search with the product image, most AliExpress sellers of what appears to be that adapter do specify, at least, that it only works with certain (mostly Huawei and Xaomi) phones. The listings aggravatingly don’t specify that it uses audio accessory mode (and some claim to support phones that I recall as not supporting audio accessory mode), but given that none of them say anything about a DAC or amp, it seems most likely that it is using that mode, and thus largely not useful.

As a not entirely pedantic point, I’d like to note that the FP4, like essentially every phone, does, of course, have an internal DAC and an amplifier (and an ADC), as it needs those for its speakers (and microphones). Instead, it doesn’t have a way to output analog audio over USB-C, or an analog jack.

I bought this one:

For me this works and has the advantage, that you can charge the phone while listening to music.

To not have a parellel discussion about audio Jack adapter I moved your post to this existing topic.


Hi folks,
I’m very new here, but have a lot of experience with using audio adapters on my USB-C phone socket.
For simple use you need an OTG adapter. Available with/without extra charging port.

For listening to serious music there are two options:
(1) BT 5+
FP4 Bluetooth supports the AptX codec. That means FLAC (cd quality) streams. Best listened to by a reasonably good Bluetooth headphone (over ear closed when used outside the house or in a house with many noises)
(2) a DAC dongle with at least a (single ended) 3.5mm jack headphone socket. Also works on a laptop or pc

  • For standard use with low-medium impedance headphones (read about this on the Internet) you could go for the FiiO DAC dongle series KA1, KA2, KA3 USB-C type (price ranges from 50-90 euros). I use the 90 euro KA3 which also supports a 4.4mm balanced connection.
  • One step up, and a very light dongle is the THX Onyx (approx. 200 euros) 3.5mm and also for higher impedance headphones up to 200 Ohm+. Works best with the Android USB Audio Player PRO app (one time purchase of approx 8 euros).
  • For those who own Beyer Dynamic type headphones with an impedance around 500 Ohm you really need a dongle with a powerfull amp like the iFi Audio GoBar approx 330 euros.

The more expensive dongles are really for HiRes listeners using streams above CD format) 24 bit and up to 192Khz (Qobuz streaming service) or MQA files (Tidal streaming service)

Sorry for all the audio tekkie stuff, but if you are a music lover and want to listen properly on the go this is the way to go.



I had thought one of the points of Type C was not needing OTG adapters; are you referring to something else here? The OTG adapters I remember were typically micro-B male to A female. Unless you want a split to provide power separately, there shouldn’t be a need to have an adapter other than a DAC+amp Type-C-to-3.5mm dongle.

AptX is a proprietary, lossy codec; it is neither FLAC, nor similar to FLAC, a lossless, open format; it is also not similar to CDDA CD audio. The FP4 does nominally have support for aptX, aptX HD, and aptX adaptive, but software support has been regressed recently, and it may not work for many users, even after the update that attempted to fix it, but fixed only aptX HD.

Another, flexible option, for people who like wired headphones, is that the FiiO bluetooth amplifiers will also work as USB audio interfaces, so using them, you can switch between wireless and wired use.

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Hi @Hans_from_Holland

Welcome to the forum and thank you very much for the insight and detail


Great to hear that you know everything better :wink:
What would this community do without you.

Hi all,

I’m interested in a Fairphone 4. I can live with most of the technical trade-offs vs. other devices, but the main hurdle left for me to overcome is the lack of 3.5mm headphone port. I have some quality IEMs, and so have no interest in wireless buds/phones.

I know a lot of people have complained about FF’s decision to drop this, but it does seem a highly questionable one. So my question is: what’s your experience of using wired earphones with the FF4, via some adapter? Which adapter do you use, and do you find that it breaks and you have to replace it?

I was reading up on USBC-to-3.5mm adapters and it seems it’s not straightforward which you need, plus they often seem to break. It’s another moving part in the chain, after all.

Many thanks in advance!

You better get used to it. The whole industry is heading wireless, let’s face it.

Best wishes,

Hello and welcome to the forum. Take a look at:

From my exprience it’s completely fine and the adapter (a cheap one from AliExpress) still works fine, but I don’t use it that often.

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In my limited experience, the adapter sold by Fairphone is quite good, as good as an adapter can be (it works and is quite solid, that’s all I ask for).
Note I mostly use that adapter for the old office headset I use when I need my hands on the mouse & keyboard while being on the phone (yes, I could use the earbuds, but the wired headset doesn’t use batteries…).

I have not yet figured out the best USB-C option for my phone, but I wanted to share some thoughts based on what I have researched.

First, a lot of the adapters with a built in DAC (which is what you need with a FP4, while some phones can send an analog signal over their USB-C port, in which case a simple passive adapter is all you need, but won’t work here with FP), and thankfully so many of the USB-C adapters have decent to great sounding DACs built into them. People usually throw around the Apple and also Samsung adapters as the best sounding cheap dongles.

However, there are a bunch of technical quirks and details that make it a lot harder to find a perfect adapter. First, I don’t remember all the technical details and terminology, and some of it probably is already covered here on this thread (because I remember reading through this thread at some point when researching). Basically, there was something about the Apple and Samsung adapters that didn’t completely follow the procedure and standards of how sound delivery over USB-C is supposed to be done, which results in a total max volume drop on many phones (maybe a 20% reduction or so?), and I think FP4 is one of these phones. Second, if you live in Europe, these adapters are further affected by some regulations in EU, which means that the European versions of the adapter have a reduced power draw that results in an even larger reduction in volume compared to the adapter sold in the US.

I used the Samsung adapter for about 3-4 months, because I read it was a bit less affected by these factors, while the European version of the Apple dongle would have as much as 50% drop in volume it could produce. Still, I noticed that when with my older phone with a headphone jack I found comfortable listening level to be just around the mid point of the volume scale, with the Samsung adapter on FP4 the same level was around 3/4th of the scale.

I largely stopped using the adapter because it became so sensitive to any sort of touch or nudges that it would constantly cut the music playback, and I think it’s due to something in the adapter itself being wonky or starting to break, because I still don’t get any disconnects with the phone when charging or moving data via USB cable and heavily shaking the cable (meaning, it’s probably not due to the USB port in the phone, nor is it due to the plug tightness of the adapter as I did tighten the grip of the plug with some pliers).

Otherwise I thought the adapter sounded wonderful and pretty neutral (no strong coloration in the voice, clear bass, mid range and treble), it also supported the mic/handsfree button of my headphones if I wanted to pause a song or skip it. The volume level wasn’t an issue for the most part, but some music with much wider dynamic range was just barely at comfortable volume levels when maxing the volume scale. Unfortunately, if I wanted to touch up the sound even a little bit with EQ, there just wasn’t enough headroom in the volume scale.

I have understood that you can get the best results weirdly enough with some Chinese brand adapters that use a specific type of DAC chip that’s very widely used by many generic adapters. Get one that seems to have a sturdy build, and since they are made by some random small brand, they apparently do skirt around some of the regulatory factors that have affected these big brand adapters.

Don’t know about the policies on this forum about linking stuff, so I’ll just say that some of the more technical information about DAC chips I found on audiosciencereview forums.

I’m not currently using any USB-C adapters since I’m still trying to figure out what adapter to get and where (in Europe) I should buy one. I’m just using some old Nokia handsfree Bluetooth receiver to connect my IEMs for casual listening.

It seems that this thread has mostly talked about adapter’s without a splitter for charging purposes, but I’m hijacking it for that purpose anyway.

I am currently looking for two different kinds of adapters that have been confirmed working with the Fairphone 4, that allow me to connect my headphones to the FP4 while charging simultanously:

  • The first type of adapter is USB C (male) to 3.5mm (female, audio) + USB C (female, charging). I have only seen the Belkin RockStar model mentioned above. Any comparative experiences in that area?

  • Secondly I’m looking for USB C (male) to USB C (female, audio) + USB C (female, charging).

Additionally I would ideally like to have a single-cable solution that works to connect my Bose headphones with a 2.5mm plug to the Fairphone’s USB C port, in order to avoid constantly loosing adpters - so 2.5mm (male) to USB C (male).

Do you guys have any experience with these kinds of adapters and can confirm which models are working (well) with the FP4? I would prefer to avoid unnecessarily buying incompatible adapters.

Did you check the list or only this topic

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Oh, no. I only checked this thread itself at first, sorry. The wiki should at least take care of the charging + 3.5mm splitter.

As far as I can tell there’s no entry for a USB C to 2x USB C splitter for audio + charging though. Any experiences with that?

I have some updates to report regarding adapters I tried:

Let’s start off with the best experience - this USB C (male) to 2.5mm AUX (male) cable by MOSWAG for use with my Bose QuietComfort over-ear headphones. The cable seems to work flawless when connected directly to the fairphone. The only downside I noticed is, that the 2.5mm side of the cable does not sit in the headphone plug as firmly as the original one - potentially due to the larger rim directly below the connector.

Now for the USB C splitters. I’ve so far tried two of those:

First off we have this two-way USB C splitter (1 charging, 1 headphones) by TRANSLIKS. When my FP4 has a significant amount of charge left the adapter works flawlessly with my default chargers for charging-only, headphones-only and both at the same time. However, if the battery has less than 25%-30% of charge left, a curious thing happens (depending on the type of charger used). For my old Motorola (Nexus 6) and Apple (iPod Nano 4th gen) chargers, the connection seems to disconnect and re-connect in short intervals once the charger is connected, which also interferes with the headphone functionality. With my Laptop’s charging port and a more recent OnePlus charger on the other hand it worked fine all the way down into single-digit battery percentages.

Secondly I tried this three-way USB C splitter (1 charging, 2 data) by MOSWAG. While listening to audio output and charging at the same time did work with this one when I tried it, once one of the two was disconnected the other one stopped working as well. Also charging, listening to music and transferring data to my laptop in parallel is not a task this adapter seems to be able to fulfill with my FP4.

Finally I tested a USB C to USB C (charging) + 3.5mm AUX (audio) adapter by the FP4. I chose this adapter/splitter by Tomost since I quite like the ‘parallel’ design of it, almost giving it the feel of an internal audio-jack. Unfortunately the audio jack seems to be incompatible with my FP4 - tested again with my Bose Quiet Comfort headphones.

So much for that. I hope some of you find this follow-up information useful - especially the USB C splitter stuff, since nothing had been reported regarding compatibility with those so far.


Not sure this is extremely helpful, but just tried an unbranded power/headphone splitter from ebay (unfortunately before finding this post!) and the headphone socket didn’t work (continued to play sounds out of FP4), the charging port worked though. :person_shrugging:

USB C Type C Up to 3.5mm Headphone Jack Male Aux Audio Adapter Cable

Hello, I bought an audio adapter that allows to connect my fairphone from it s USBc entry to a jack so as to connect my music to my car radio (that doesn t have bluetooth).
It doesn’t work, the sound still comes from the phone and not the radio when connected…

Hi and welcome, i moved your post here maybe you find answers above or this list