Review: Apple vs Google USB-C Headphone Adapters

[multiformous]

If you play this sound through the Apple USB-C to 3.5mm adapter you will hear a static like crackle in addition to the rumble:

https://www.audiocheck.net/Audio/audiocheck.net_polarity_lowrumbleOK.ogg

Source:

https://www.audiocheck.net/soundtests_headphones.php

I thought I had a defective adapter so I bought another one and it does the same thing. Doesn't matter what headphones are used. Happens on my MBP and a Dell laptop.

Normal 3.5mm output from MBP, Dell laptop, or any other device does not cause this crackle.

The Lightning to 3.5mm adapter does not have this issue. I also bought the Anker USB-C to 3.5mm and it doesn't have this issue either. So it's an issue exclusive to the Apple USB-C to 3.5mm adapter.

Is there something intrinsically wrong with the adapter design that causes this?

That's kinda funny. When I play the test file in foobar with the Apple dongle, my mouse and keyboard stop working! They come back to life after the file stops playing, though. Tried it with a few other dongles and didn't have that issue. Strange. And yes, I hear that intermittent crackle when using the Apple dongle with this test file.

 

[AdriftAtlas]

That's kinda funny. When I play the test file in foobar with the Apple dongle, my mouse and keyboard stop working! They come back to life after the file stops playing, though. Tried it with a few other dongles and didn't have that issue. Strange. And yes, I hear that intermittent crackle when using the Apple dongle with this test file.

Umm, how would your mouse and keyboard stop working? Is the dongle hosing the USB bus?

 

[AdriftAtlas]

The Apple appears to be clipping or something. Maybe something to do with DC filtering...

Could it be compression artifacts aka aliasing? Sorry for the newb question, but what do you mean by DC filtering?

 

[BeerBear]

By DC filtering I mean removing the DC offset, which sometimes involves removing the lower frequencies (high-passing). I don't think the problem is DC offset here, but it's definitely caused by the strong low frequency content.
Here's a simpler test signal you can use: a 3Hz sine wave. When played through the Apple dongle it produces some kind of ticking noise. This shouldn't happen and it doesn't happen with two other soundcards that I tried, only with the Apple.
Maybe it's running out of power and distorting?

Anyway, I don't really know much about this stuff, hopefully some experts will chime in...

 

[oleg87]

Guessing it's going into some kind of momentary DC protection mode and cutting its output, before the signal wiggles enough that it re-enables itself, resulting in the crackle. If I could find my dongle I could hook its output up to a scope and see if that's revealing, but unfortunately I have no idea where it is.

 

[paudio]

By DC filtering I mean removing the DC offset, which sometimes involves removing the lower frequencies (high-passing). I don't think the problem is DC offset here, but it's definitely caused by the strong low frequency content.
Here's a simpler test signal you can use: a 3Hz sine wave. When played through the Apple dongle it produces some kind of ticking noise. This shouldn't happen and it doesn't happen with two other soundcards that I tried, only with the Apple.
Maybe it's running out of power and distorting?

Anyway, I don't really know much about this stuff, hopefully some experts will chime in...

I tried 3 different players I don't hear any sound at all in your recording?

I hear something on the original ogg with the rumble but it's pretty quiet compared to the rumble. Can't hear it on my normal 3.5mm jack though

 

[AdriftAtlas]

By DC filtering I mean removing the DC offset, which sometimes involves removing the lower frequencies (high-passing). I don't think the problem is DC offset here, but it's definitely caused by the strong low frequency content.
Here's a simpler test signal you can use: a 3Hz sine wave. When played through the Apple dongle it produces some kind of ticking noise. This shouldn't happen and it doesn't happen with two other soundcards that I tried, only with the Apple.
Maybe it's running out of power and distorting?

Anyway, I don't really know much about this stuff, hopefully some experts will chime in...

Yup! Your sample has the Apple dongle clicking away at 23% volume or above. Tested with onboard sound from my laptop and all I hear is faint whooshing.

Something is definably odd about the Apple dongle.

 

[paudio]

I am guessing all the really low spectral data in the original file is causing some sort of issue. I loaded it into reaper and added a spectral edit to remove 0-69hz and it I think it goes away. First half of file I will attach is filtered and the second half is not.

 

[multiformous]

Umm, how would your mouse and keyboard stop working? Is the dongle hosing the USB bus?

Maybe? I get "power surge on USB hub" notifications on my ancient franken-PC, but things keep working. I don't know enough about this sorta thing to say what's actually happening.

 

[BeerBear]

I tried 3 different players I don't hear any sound at all in your recording?

I assume you mean when playing the 3Hz test signal. The ticking/clicking when playing through the dongle is pretty quiet, but it should be audible at full volume. I'm attaching a recording of it (edited after recording, with some hi-pass, so it's easier to hear).

It's also possible that the "EU" dongle, if you're using that, doesn't suffer as much from this. I'm using the US version (A2049).

 

[AdriftAtlas]

All of these also cause clicking on the Apple dongle but not my other sound cards:

Sine Burst Tones (20-200 Hz)

Audio Test Tones : using sine bursts to check your subwoofer and room modes.

www.audiocheck.net

 

[paudio]

I assume you mean when playing the 3Hz test signal. The ticking/clicking when playing through the dongle is pretty quiet, but it should be audible at full volume. I'm attaching a recording of it (edited after recording, with some hi-pass, so it's easier to hear).

It's also possible that the "EU" dongle, if you're using that, doesn't suffer as much from this. I'm using the US version (A2049).

Using https://www.szynalski.com/tone-generator/ I can reproduce the clicking but it's really quiet on my dongle and goes away at 9Hz.

US dongle here. I just didn't hear any audio from the file. Maybe a local playback issue.

All of these also cause clicking on the Apple dongle but not my other sound cards:

Sine Burst Tones (20-200 Hz)

Audio Test Tones : using sine bursts to check your subwoofer and room modes.

www.audiocheck.net

I would bet it is really low frequency sound causing the issue. Like <15Hz?

Edit: I don't think I hear it on any of these bursts which seem to start 12Hz above where I can hear clicking on my US Dongle.

Edit2: Comparing https://www.szynalski.com/tone-generator/ 0-30hz on both Surface Pro 8 3.5mm output and the Apple Dongle is that the 3.5mm output is very rolled off under 30hz compared to the Apple Dongle.

 

[AdriftAtlas]

Edit2: Comparing https://www.szynalski.com/tone-generator/ 0-30hz on both Surface Pro 8 3.5mm output and the Apple Dongle is that the 3.5mm output is very rolled off under 30hz compared to the Apple Dongle.

If I set the frequency to 20Hz and start and stop the playback I hear that clicking noise when it starts playing. This happens irrespective of whether other audio is quietly playing in the background or not, so it's not the DAC turning on and off. It almost sounds like the DAC is overloading.

 

[Rollingsound514]

On my Iphone with an NX4 DSD I can play lossless bit perfect from roon via iphone, but with the 3.5 mm apple adapter it always changes sample rate to 48khz, even 44.1 stuff...
Has anyone solved this or is it just a quirk of roon and this adapter?
Thanks

 

[DeLub]

On my Iphone with an NX4 DSD I can play lossless bit perfect from roon via iphone, but with the 3.5 mm apple adapter it always changes sample rate to 48khz, even 44.1 stuff...
Has anyone solved this or is it just a quirk of roon and this adapter?
Thanks


View attachment 309076

The dongle only supports 48khz

 

[Jimbob54]

The dongle only supports 48khz

On my phone it will do 44.1 and 48.

Edit - but mine is android playing through uapp. Suspect on iPhone it does everything at 48.

 

[somebodyelse]

My A2155 (EU spec version) under linux only offers 48, at least with headphones attached.

Spoiler: format details

$ cat /proc/asound/card1/stream0
Apple, Inc. USB-C to 3.5mm Headphone Jack A at usb-0000:00:14.0-5, full speed : USB Audio

Playback:
  Status: Stop
  Interface 1
    Altset 1
    Format: S24_3LE
    Channels: 2
    Endpoint: 0x02 (2 OUT) (SYNC)
    Rates: 48000 - 48000 (continuous)
    Bits: 0
    Channel map: FL FR
  Interface 1
    Altset 2
    Format: S16_LE
    Channels: 2
    Endpoint: 0x02 (2 OUT) (SYNC)
    Rates: 48000 - 48000 (continuous)
    Bits: 0
    Channel map: FL FR

 

[paudio]

Windows A2049

Likely the chipset is quite capable but driver support depends on the platform.

 

[Rollingsound514]

Windows A2049

View attachment 309139

Likely the chipset is quite capable but driver support depends on the platform.

Interesting that Iphone can do sample rate switching with other dacs like the NX4, but not it's own dongle...

 

[Inhuman]

anyone has Apple Earpods type C yet??? still 0.5 limit on ANdroid or not?