Recycling Android smartphones or mobile phones to listen music on the air

[klirren_65]

Millions of mobile phones rot in the drawer, because of missing security updates, weak battery etc.
A small amount to give them a "dignified" second life:

a. Hardware

In general smarthphones support the audio stream out via USB (to the next DAC). Bit for bit - without losses! And if wireless charging will be supported, perfect, there is no need to power off for recharging.

b. Software

The following two software recommendations come from f-droid.org, a software portal - no advertising or tracking, open source, etc.

F-Droid - Wikipedia

en.wikipedia.org

Getting the apps, you do not need a membership of the famous US-company.

RadioDroid: Look up online radio streams at RadioBrowser and listen to them.

AntennaPod: Easy to use and adjust Potcast-Manager

c. low budget solution

Samsung Galaxy S5 (20 $) equiped with a free custom-rom (Android 7.x)

Have fun!

 

[KaeliKoo]

LG "V" series phones with 4-6gb RAM and built-in quad DAC make for excellent music players - that has been my experience.

















































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[Vincent Kars]

In general smarthphones support the audio stream out via USB (to the next DAC). Bit for bit - without losses!

Android resamples everything to 48 kHz including usb audio.
Won't say it is a audiophile crime but it is bit imperfect by design.

There are a couple of programs bypassing the Android audio and by doing so allow for automatic sample rate switching.

One moment, please...

The gist of your post, using an old mobile as a transport, appeals to me. Basically a mobile is a touch screen controlled audio source. The heir of the Squeeze box touch.

 

[Timcognito]

Android resamples everything to 48 kHz including usb audio.
Won't say it is a audiophile crime but it is bit imperfect by design.

Is that true with phones with the Snapdragon chipset?

 

[klirren_65]

Android resamples everything to 48 kHz including usb audio

Right, but in general radio stations support 48 kHz.

 

[klirren_65]

Android resamples everything to 48 kHz including usb audio.

Correction: In this case for those "sounding" apps above it doesn't matter.

 

[pallas]

Android resamples everything to 48 kHz including usb audio.
Won't say it is a audiophile crime but it is bit imperfect by design.

I guess bit-perfect USB output won't unfortunately be possible with a custom rom on the Android phone.

 

[Timcognito]

I guess bit-perfect USB output won't unfortunately be possible with a custom rom on the Android phone.

Not so fast, Amir says, "While I have only tested two modern smartphones so far, the LG G7 ThinQ easily gets my recommendation for its audio performance. Well done LG!"

Review and Audio Measurement of LG G7 ThinQ Smartphone

This is the review and measurements of the audio performance of LG G7 ThinQ smartphone. It was purchased by my son a couple of weeks ago. It retails for USD $750. Its claim to fame is inclusion of an ESS quad (four paralleled) DACs ES9218P with integrated headphone amplifier. There are...

www.audiosciencereview.com

 

[pallas]

But this review was with the original OS, not a custom rom.
With a custom rom there'll be no access to Google Play Store, therefore no Neutron or USB Audio Player Pro to bypass the upsampling.

 

[Timcognito]

But this review was with the original OS, not a custom rom.
With a custom rom there'll be no access to Google Play Store, therefore no Neutron or USB Audio Player Pro to bypass the upsampling.

I think, Snapdragon supports up to 24-bit/192kHz resolution. LG has firmware upgrades up to late 2023. Maybe I'm not following something here.

 

[ZolaIII]

I think, Snapdragon supports up to 24-bit/192kHz resolution. LG has firmware upgrades up to late 2023. Maybe I'm not following something here.

Codec suports 192 KHz (or even more I don't recollect anymore) 32 bit but OS doesn't and unfortunately you can't redirect internal DAC to costume output (you can but no one wrote one so far) not even with Neutron player which has good suport for QAudio codec. Same supports operating and in H class mode but no one ever wanted to enable it even on costume ROM's because it uses little bit more power. Google whose rumbling about rewriting audio output for a long time but as I don't follow Android development anymore all that much I don't know did it happen to today.

 

[Timcognito]

Codec suports 192 KHz (or even more I don't recollect anymore) 32 bit but OS doesn't and unfortunately you can't redirect internal DAC to costume output (you can but no one wrote one so far) not even with Neutron player which has good suport for QAudio codec. Same supports operating and in H class mode but no one ever wanted to enable it even on costume ROM's because it uses little bit more power. Google whose rumbling about rewriting audio output for a long time but as I don't follow Android development anymore all that much I don't know did it happen to today.

Thanks but for less $100 one get an LG G and V series phone and have excellent playback through the headphone jack, without fooling around. Plus ability to add 1 Tb of FLACK storage. Maybe I'm not sophisticated enough to understand the goal here.

 

[Vincent Kars]

Snapdragon supports up to 24-bit/192kHz resolution

I don't think it the hardware is the problem.
Most OS are designed with multiple audiostreams in mind. A logical consequence is that there must be a default.
In case of OSX the user can set this in Audio Midi or in Win in the Audio panel.
All the time it is fixed so any audio not matching this rate has to be resampled.
Likewise by bypassing the OS audio, automatic sample rate switching is possible but you need an exclusive lock on the hardware.

I think Android works the same. It has a default (48) but no user interface to change this. However, developers can bypass the Android audio stack.
This has become part of Android 14. At least in case of USB audio it is possible to have automatic sample rate switching.
Might very well be that the same trick can be applied to onboard audio like the Snapdragon. At least the LG mobiles are able to do so with the onboard DAC.

 

[ZolaIII]

@Vincent Kars for very long time it's possible with using costume USB Audio 2.0 driver but only on USB. Plenty of CS43131 dongles for 40$ or less, now even BT LDAC dongle clips with same DAC for 50$ or less.

 

[A Surfer]

Still, the point that we can use our retired smart phone as a music source is valid. I have been doing that for years. First my retired LG G7 and now my retired G8.

Fantastic and convenient solution for use as a streaming device.

 

[ZolaIII]

Thanks but for less $100 one get an LG G and V series phone and have excellent playback through the headphone jack, without fooling around. Plus ability to add 1 Tb of FLACK storage. Maybe I'm not sophisticated enough to understand the goal here.

You should still be beater with new cheap phone with large battery and USB or BT DAC. Resasasempling on Android is not always bad implemented and when it's not 48 KHz is perfectly fine. I am waiting for my 5+ year's old Sony to give up with battery or something else but it's pretty stubborn so far. I will miss it greatly for integrated DLNA server and some other stuff when it finally happens. With this prices I doubt I will go for another Sony, other than that it's more than fine by me.

 

[Timcognito]

Still, the point that we can use our retired smart phone as a music source is valid. I have been doing that for years. First my retired LG G7 and now my retired G8.

Fantastic and convenient solution for use as a streaming device.

With nice OLED screen and plenty of storage. Something a dongle does not have.

 

[ZolaIII]

With nice OLED screen and plenty of storage. Something a dongle does not have.

Lol you can buy a cheap Xiaomi Redmi 13 4g with 256 GB storage and SD card for 170$ probably even less on special offer and if you want more there is always USB dongle or LDAC reciver for cheap.

 

[pallas]

Using a Xiaomi Redmi 10 (2022) with USB Audio Player Pro as Hifi player to feed the DACs.
Got that phone brand new, in January this year, plus a 512 GB memory card for 150$.
Regular price here, not a special offer.

Before that I had a Samsung A5 from 2017. Still works as an audio player at my girlfriends home, but the USB micro port was getting annoying for me, as all my other devices now have USB C. Plus the battery has seen better days.

 

[DWPress]

Or set your old iPhone up as an inline convolver/EQ.