Discussing the sustainability of removing the 3.5mm jack

My understanding is that all audio files and streams are digital so they have to be converted for the speakers. Feed to the USB is understandably digital.

There is a DAC in the phone to power the speakers and it could be just routed to an ear jack. ??

I’m not sure whether this has the same power and quality as a dedicated headphone output.

I’m pretty sure in the case of the FP4 with it’s stereo output it would be fine for earbuds, not that this is meant to be an argument against removing the 3.5 jack.

To those that are wondering about sustainability rather than the technical issues:
Fairphone, from what I can tell, made the phone more sustainable i.e. better water and dust resistant by removing the jack; that’s their business.

The ecological main difference is that, in really most of the case (maybe it’s not for the soc in FP4, I haven’t look datasheets, but there’s a speaker, so it should have a DAC), SOCs integrate the DAC, and when you design your mother board, you just have to wire it to the headphone amp, and voila. You benefit of all the design to have the good electrical tension, you use some of the same capacitors for exemple. You got your DAC into the case of the phone, so you benefit of the phone protection, and if ever you lose or break your phone, the loss of the components you needed to had for the headphone amplifier is almost avoided by the fact that, in comparaison with the phone, this is almost anything. (and you benefit of the fact that there is only one factory, supply chain, etc…). By avoiding the 3.5mm output, you just make the economy of the barrel and the amplifier and a some simpler design.

If it’s outside, you’re facing multiple issues. USB is, by definition standard, so, you’re note just have an I2S signal for the dac to operate, You got an an I2C that you first need to manipulate to get the I2S signal which was first outed by the soc . The standard output of USB is 5V if I well remember. If the dac, , the amplifier or anything else in the “usb-c adaptater” need a 3.3v tension, you need to add a tension converter (that already exists in the phone but can’t be reused…), one more dac, you got so much more plastics, metals than for just adding it in the phone body (the weight of this kind of things is about 10/15g, you don’t have 10/15g less in the phone by avoiding it.).
So, you need one more factory, another supply chain (so, much more petroleum) to build lot of hardware that is only used to do again what is already done in the phone, and perfectly useless.
At the end, you have useless electronics components in objects that are garbageable by design, because it’s easy to lose, to break, your got weak cobber wire instead of solder it on the mother board and you’ll probably buy two or three during your phone lifetime. You weaken your USB-C port on your phone because of the mechanical constraints we described above and you just made the economy of the amplifier and the barrel in the phone. So the ecological impact of having it in external is absolutely huge, even if only 10% of the consummers use a conventionnal headphone.

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You can use a USB-OTG cable with an Audioquest Dragonfly, together with a wired headphone with ANC you got far superior quality to Bluetooth, with the only disadvantage being that you got more external peripherals and that you have the wire to take into account.

I believe the trick is to have the cable in the USB-C on the upside instead of the downside. That way, there’s no strain on the USB-C port from the weight of the smartphone.

Agree with most of your analysis but not that.

Huge is a comparative word and in terms of ecological impact it’s absolutely miniscule. How much energy, taken from finite resources and converted to heat and ~ just loads of stuff ~ does it require just to discuss this so called ‘ecological impact’? and will we stop? No we will keep going as we like to think we can make a difference. We surely can but it’s not ecological to even try.

I’m not really sure, if it’s that easy and the quality of such a solution is sufficient for high quality headphones.

Yes and no…

This is what is done on all cheap and mid-range phones (and most of the flagships also, I never heard about a phone with a dedicated high quality DAC), this is what was done on the FP3, and the quality is good-enough.

The sound quality is most due to the quality of capacitors for the headphone amp, not that much the dac (exactly, most SoC’s DACs are largely good enough to have a good sound for most of the 300€ headphone if you have a good headphone amp).


I wished to use the most useful phone that used the least possible resources and parts.

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You know, you don’t have to feel obliged to write something if you have nothing at all to say.

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Analog phones have no digital-to-analog converters and no radio receiver/transmitter.
Didn’t you know that? It doesn’t take an electronics engineering BA.

I understand. With the Fairphone, they have for example used extra resources to create the modular design though - you aren’t replacing the bare components, but the components are encased in easy to assemble plastic/metal units. You could say that this is a trade off, but I don’t think it would be profitable if they didn’t make SOME compromises such as this.

I think the most important question is if you they have increased the likelyhood of people keeping their devices for 5+ years, without having to repair hopefully. This isn’t something we can know until those 5 years have passed.

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dont know about sustainability, but maybe get an electrical engineering degree and do it yourself similarly to that apple X with usb-c mod guy, selling his first born on ebay for like 100grand. pays off even your tuition fees just as well ;p

was all over the interwebs just the other days

iphone X with usb-c mod selling on ebay for like 100k USD

'sides its open source or even open kinda hardware that we deal here with a fairphone, ought to be even simpler and possible? takes off those profits then though ;(

Dear Allessandro

Clearly I have things to say, I am not struggling here. Maybe you could point out what it is that you find so offensive that you urge me not to respond?


Your comment to @incannus is also a little harsh and rude. I’m sure many people are unaware that analogue phones work as you state and I would not presume a certain individual does or does not.

So you could be a little more fore-giving. But please do not hesitate to criticise

All the best

That’s an iPhone X (a device from 2017) with USB-C. The price of 100k is nowhere near the realistic value of it, its a collector’s item. I found other much cheaper iPhones with USB-C (iPhone 8 and 12 at least). There’s probably some guides on how to do it, Snazzylabs IIRC did it long ago as well. IIRC on the first iPhone where Apple stopped with 3.5 mm it was proven the smartphone actually had room for the 3.5 mm port, they just left it out. Perhaps also for IPx, who knows.

I wonder want your response would be to the following:

" True Wireless Stereo Earbuds

Your sound, now with extra sustainability."

The market is also heading non fairtrade, non sustainable… why bother fairphone, is it that easy?



I’m pretty sure in the case of the FP4 with it’s stereo output it would be fine for earbuds, not that this is meant to be an argument against removing the 3.5 jack.

To those that are wondering about sustainability rather than the technical issues:
Fairphone, from what I can tell, made the phone more sustainable i.e. better water and dust resistant by removing the jack; that’s their business."

And as a result they did NOT improve the IP rating?.. Does not make sense to me!

You are quoting other posts. You will not find such a statement on the Fairphone website. This is a user forum, the information on here is often hearsay, though mostly verifiable. Not this though.

You will find from Fairphone that the FP3 is not IP54 rated, now the FP4 is :slight_smile:

It’s not IP54 rated, it’s true, but IP54 is a fairely poor rating, it’s just a little upper than the FP3 would have been if it was rated.

Here is an IP68 rated phone : https://www.nokia.com/phones/fr_fr/nokia-800-tough?sku=16CNTB01A10

It got a 3.5mm barrel…

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