ear phone noise

[cam1965]

Hi.
The ear phone in astro produces a lot of noise when connecting and when listening music or any audio or even any video in youtube, etc.
I also related here a problem with the radio app.
Cosmo does not have these problems.
Does anyone have these same problems? Thanks.

Note :
With display is  off or locked  there is no noise   when music is playing

[Oliver Riesen]

Hi cam1965,

I connected a head set and had the same problem.

Regards
Oliver

[cam1965]

Hi Oliver. Thank you for the information.

[vader]

This has been an issue since the gemini. Normally, when the audio starts, the noise goes away. In FM radio mode, when you have a strong signal, the noise goes away too. Turning off the screen also helps. You can solve the noise issue by using Bluetooth headphones, or a USB-C to 3.5mm jack.

[zevv]

The problem is that androids audioflinger is not properly switching down the analogue output stage of the codec, leasing to residual noise on the headphone output. In the early days of the gemini someone made a fix for this, but I don't know where to find this. This should theoretically also be possible for the astro, given that we have the proper android sources around somewhere.

[Daniel W]

My Astro leaks quite a bit of various digital clock signals into the analogue audio path. I plugged it into a digital recorder and captured two examples of what different states of activity might sound like. In both recordings, I used a soft clipper to chop 12 dB off from the loudest pops and then I saved the files as mp3 with joint stereo and an average bitrate of 128k. While perhaps a bit rubbish by today's standards, this isn't high fidelity to begin with.

OESF doesn't seem to embed a player for the mp3 files, so, for now, they are just attached files. Especially in the DC example, beware that the music is quite loud compared to noise, but the noise is still clearly audible. Heavier music may, to some extent, drown out the noise "better", but I picked a hymn to (a) avoid copyright and (b) illustrate the issue.

Astro DC noise (on battery all the time)

astro DC noise.mp3

1. Just plugged in headphones.
2. Taps home.
3. Either Android "quiets down" or the Astro actually lowers the volume.
4. Navigating app drawer, starting music app (Caustic)
5. Playing some music at would normally be a pleasant listening volume.
6. Stopping playback, leaving app, returning to home screen.
7. Either Android "quiets down" or the Astro actually lowers the volume.

Astro AC noise (using the included EU plug AC adapter).

astro AC noise.mp3

1. Headphones plugged in, Astro on battery, screen on, doing nothing.
2. Plugging in the included AC adapter.
3. Doing nothing
4. Either Android "quiets down" or the Astro actually lowers the volume.
5. Opening apps drawer.
6. Scrolling apps drawer.
7. Starting my music app of choice (Caustic from Single Cell Software).
8. Playing some music at would normally be a pleasant listening volume.
9. Stopping the playback.
A. Exiting Caustic via its menu.
B. See 4.
C. Taps the screen.
D. Opens the app drawer.
E. See 4.

Edit 2022-Dec-28:
While it might not matter much here, I realized I cropped the scales off the axes and failed to name my tools, sorry about that. Just in case anyone wants to know: The recordings were made on a Zoom H1n at 48kHz in 24bit (though the H1n is so noisy, I doubt those extra bits matters much) and the screenshots are from Audacity 3.2.2 on Windows 11. I probably had the Astro att full volume, set the H1n recording level a tad below 7 out of 10, and kept it there for both recordings. Two pops (when plugging in the charger) still clipped, but everything else was below -12dBFS (hence the soft clipper). While the clipper may have altered the dynamics a tad, it mostly should have worked as a normalizer that could handle the presence of those two clipped moments.

The vertical axis is in dB with a range of (only) 36dB, so even the smallest bumps shown are at least above -36dBFS and should thus be quite audible at a reasonable volume setting. The horizontal axis is, as usual, time. When the screenshots were taken, the "DC" file was 52.376s long and the "AC" file was cropped to one minute (and zero milliseconds).

[ZimbiX]

@Daniel W: Wow, I thought my Cosmo's noise was bad! This is a serious problem - I don't have my Astro yet, but it sounds like this would prevent you from enjoying music at all! Great idea to include recordings and annotate them

Edit: I've linked to your comment from the GitHub issue

[cam1965]

@Daniel W: Wow, I thought my Cosmo's noise was bad! This is a serious problem - I don't have my Astro yet, but it sounds like this would prevent you from enjoying music at all! Great idea to include recordings and annotate them

Edit: I've linked to your comment from the GitHub issue

Yes , really a big problem .I am using an usb earphone without problems.But the internal radio app when you select the output to speakers .... it is a trash.

[sobukus]

You can solve the noise issue by using Bluetooth headphones, or a USB-C to 3.5mm jack.

Can you be more specific about which type of USB-C to 3.5mm jack? I gather there are types that simply route analog audio from the USB-C port (the same audio path as the 3.5mm? a separate mix?) and types with an internal DAC that circumvent any A/D in the Astro.

[Daniel W]

The problem is that androids audioflinger is not properly switching down the analogue output stage of the codec, leasing to residual noise on the headphone output. In the early days of the gemini someone made a fix for this, but I don't know where to find this. This should theoretically also be possible for the astro, given that we have the proper android sources around somewhere.

While it should help to turn off the appropriate analogue stages when no audio is playing, I suppose they must be on while audio is playing? On my Astro, which I think carries over to the common case, this noise is audible over, and sometimes louder than, intended audio. Could software could do anything to alleviate that?

Can you be more specific about which type of USB-C to 3.5mm jack? I gather there are types that simply route analog audio from the USB-C port (the same audio path as the 3.5mm? a separate mix?) and types with an internal DAC that circumvent any A/D in the Astro.

I am (somewhat confidently) guessing that while some of this noise may bleed through via USB power and ground, any audio amplifier that's physically outside the Astro, and receives its audio digitally, should be significatly less affected.

Wireless and digital, Bluetooth should be immune to such analogue noise, but the BT version supported by the Astro, has too much latency for, say, playing software instruments, and you get one more thing to keep charged.

For size, price and convenience, I'd frist try an(y) amplifier, i e an USB-C to 3.5mm active "adapter" (with its own DAC) powered by the Astro. As a step up, I'd look for a wired headphone amp with its own power source.

(Edited 2023-Jan-01 to better specify what kind of "adapter" I meant.)

[Daniel W]

Replying to myself, I plugged my Zoom H1n into the left side USB-C jack of my Astro, set the Zoom to work as a "PC" Audio I/F and plugged headphones into the Zoom. While not particularly practical, it gave me 16 bit digital audio at 48kHz sample rate out of the Astro, with no noticeable noise or distorsion, which, to me, suggests that a USB-C to 3.5mm adapter with an internal DAC should work.

At first, I couldn't listen to the radio via the H1n, as the radio needs the analogue headphones as antenna, which seemed to get priority, so the headphones got the audio, with that "~120 BMP waltz metronome" going on. When I later tried again, though, the audio came via the H1n, so maybe it matters which thing was plugged in last.

There is a menu option in the radio app, to switch to "speakers" instead. This worked on the Cosmo, but when the Astro activates its speakers, it loses reception, as if it tries to use the speakers as the antenna too.

When I tried a third time, by first plugging in a headphone extension cable as antenna and then my Zoom H1n as Audio I/F, the Zoom got the radio audio, so at that point, I could listen via its little speaker, or plug headphones into the H1n.

Sorry if I'm rambling, but this seems to suggest that a small USB-C to 3.5mm adapter with an internal DAC and just an aux cable or something to use as a radio antenna, could cover my use cases, until (if) a fixed firmware (if even possible) gets released.

[gymbo]

There is a menu option in the radio app, to switch to "speakers" instead. This worked on the Cosmo, but when the Astro activates its speakers, it loses reception, as if it tries to use the speakers as the antenna too.

Planet keep on inventing stuff, now the speaker antenna!

[vader]

I did a bit of testing with the 3.5mm jack over Christmas. There is something CPU based - maybe GPU causing the sound. I tried many dev options including restricting BG processes with no luck.

When the screen is off, there is no noise. When the lock screen is showing, there is no noise. When you unlock, the noise appears. Using BT or USB headphones, there is no noise, as others have said. On my astro the sound is quite soft, so any reasonably loud audio drowns out the noise

I too have the fabled speaker antenna for the FM radio

EDIT: plugging in a dummy 3.5mm cord (eg a synth patch cable) in a strong FM area means you can use the speaker with no noise. It is a pitty the speakers are so tinny.

EDIT 2: Using an equaliser and dropping the 4kHz responnse (or increasing everything bar 4k) does wonders for the small speakers. Almost sounds good. Response under 60Hz is nn existant so don't expect booming basses.

[Daniel W]

I have also done some testing.

The only USB-C to 3.5mm DAC headphone adapter my local town former-schoolmate-and-his-wife IT shop had in store, was from the domestic brand "Champion", so I don't know who really makes it.

The (Swedish only) product page https://www.champion.se/usb-c-till-35mm-dac-adapter/ says fairly little about it; size, weight, article numbers, picture, boxshot, "made from aluminium" (just the 3.5mm part, it seems, as the USB connector casing feels like plastic), that it should work with smartphones, tablets, macbooks, laptops or "computers" and finally there's link to a "EU-declaration of Conformity", with no further product information.

The box only adds "made in China" and recycling instructions (for the box). It disagrees with the web page about the length of the adapter, and both are wrong. My ruler says 11cm in total. As the product page could move or disappear, here's some pictures of my own:
(I hereby declare all pictures I upload to this thread as public domain - cc0 - but I'm not a lawyer, so please be careful.)

 

 

When plugged into a Windows computer, it presents itself as "GHW USB AUDIO". According to Windows it supports two channels (stereo) of 16 bits at 48 or 96 kHz sampling rate (output only, this is unfortunately only a headphone, not a headset, adapter). The hardware Id starts with VID_31B2 which a search engine said is KTMicro Inc. I suppose they make the chip inside. Anyway, enough about the adapter. Any similar product should work, I think.

Edit 2023-jan-21: Though the English text on the box says "headphones or earphones", it mentions "headset" in the Swedish text. I checked in the Windows device manager again and, yes, there's an "GHW USB AUDIO" input device too, which supports once channel (mono) of 16 bits at 48 kHz sampling rate. As you can see on the photos, my Astro showed the "headphones" icon when I plugged the adapter into it, making me believe it was output only, but that was because I had headphones plugged into the adapter. When I used a headset (or nothing), I got the "headset" icon. My Cosmo, for reference, shows the "headphones" icons regardless. So far, I haven't got the input to work on either Planet device or on my Windows laptop. I can select in it (in Windows, Android does that for me) but it just records silence.

On its own, the adapter works in either port of the Astro:

 

When using it with the FM radio, plug in whatever you use as antenna (an aux cable in my case) first and then the headphone adapter. Whatever is plugged in last, gets the audio, so would you happen to do it in the wrong order, just unplug the headphone adapter and plug it back in to grab the audio output.

If you have the headphone adapter in the left hand port and the charger in the right hand port, the adapter works and the Astro charges (slowly), but if you have the headphone adapter in the right hand port and the charger in the left hand (somewhat faster charging) port, the Astro does not charge. If you plug in the charger first and then the adapter, charging stops.

 

If I listen to the FM radio using the headphone adapter, it seems the radio can't immediately tell if I unplug the aux cable, but I promptly lose all reception. Weirdly enough, if I do this while the charger cable is plugged in (regardless of whether it has a power source in the other end), I still have decent radio reception, though with a bit of digital noise in it. Is the radio using the ground plane as an antenna or what?

For the heck of it, I first plugged in my headphones into the 3.5mm jack on the Astro, so I could start the radio. Then I plugged in headphone adapter (without the headphones) into the left hand port, and finally the charger cable. Then I moved the headphones to the adapter. The idea was that if I don't have an extra 3.5mm cable on hand, maybe I could "jumpstart" the radio with the headphones and then move them over to the adapter, to get a bit better sound.

Most of the times, hotplugging the headphones into the adapter would trigger Google assistant to tell me the time, and then, somehow, the radio found out it had lost its antenna cable. After a visit to Settings > Apps & notifications > Default apps > Digital assistant app > Default digital assistant app > none I could actually pull it off. I was still prompted to active Google assistant, but the radio kept going. After a while it figured out it had no cable and disabled its UI, but kept playing.

Edit: Typos.

[Daniel W]

I just edited the previous post to fix a fact error. This thing does have an input after all, but, thus far, I haven't got it to work...