Asus MU3C-AD(M) Dongle DAC - First impressions and basic measurements

[staticV3]

This is a first look at the Asus MU3C-AD(M) dongle with ES9260Q DAC chip. On AliExpress it costs $20.

As I'm currently incapacitated with a broken hand, these will be some basic impressions and measurements with a multimeter.
If there's enough interest, then I'll do a full set of measurements with SINAD, Dynamic Range, 50mV SNR, Jitter, Zout, Load Sweeps, all that jazz.

First, the basics:
This DAC can play back up to 24bit, 96kHz content. On Windows, there are some enhancements on offer, too.

An ADC is built-in for making calls with your headset. It records at 48kHz, 16 or 24bit.

Strangely, the Asus dongle lacks UAC2 hardware volume control.
In practice, that means that users on macOS, iOS, or iPadOS cannot control volume like normal and the DAC will be locked to 100% volume.
If you press the volume keys on your Apple device, the OS will show this icon:

Volume sliders inside YouTube, Spotify etc. will continue working.

If you're on Windows or Android, then this is not a problem since those OSs will just use their own software volume instead.
However, if you're using foobar2000/AIMP/Audition/... with ASIO or Wasapi Exclusive output, then just like on Apple, the regular OS volume control will be disabled. Volume control programmed into the software will continue working.
If you use USB Audio Player Pro/Hiby Music/Neutron with Bit-perfect enabled, then the DAC will be locked to 100%.

According to ESS, the headphone Amp built into the ES9260Q will output 1Vrms max. With my multimeter I'm seeing 1.05Vrms (at 60Hz):

Let's take a look at output impedance next.
First play a 1kHz sine and reduce the output a bit.

Then put a 10.49Ω dummy load across the output and measure again

Paste it all into a handy calculator and voilà:

Output impedance is approximately 0.21Ω at 1kHz.

Next, let's take a look at how much Phantom power the dongle will supply to your microphone.
First, unloaded:

and with a Primo EM272 as load:

not bad.

Lastly, here's how much current the dongle will draw from your USB host, compared to some other portable DACs:

That's all I have for now. If you have questions or specific measurements that you'd like to see, comment them below and I'll see what I can can do.

 

[tifune]

9038D6K?

 

[staticV3]

9038D6K?

The original 9038D hasn't been available for about half a year now due to exploding silicon prices.
While waiting for silicon prices to recover, IVX prepared an improved version of the 9038D called 9038D6K. This version became available two weeks ago.

Improvements are:
-slightly lower noise and distortion
-CTIA headsets work without adapter (though there's no mic input)
-improved EMI resistance
-higher capacitance for power rail filtering

Here's 1kHz THD+N and 48kHz Jitter of my 9038D6K. You can buy one here.

 

[staticV3]

@Jimbob54 when sharing AliExpress links, you can delete everything after ".html". The rest is just worthless tracking info.

 

[Jimbob54]

@Jimbob54 when sharing AliExpress links, you can delete everything after ".html". The rest is just worthless tracking info.

Imma just delete the whole post anyway - but cheers for the tip

 

[conandrum]

I want a DAC&AMP to use with my Android phone for music and phone calls.
I was over the moon with the Cyrus Soundkey (~17db boost)...but phone calls were going to my phone's speaker.
Will this device be suitable and loud enough?

UPDATE 20 Jan 2024
-----------------------
The reason why phone calls do not come out of the USB DAC is because the Android device does not support calls via DAC.
Just tried a phone call with the Cyrus Soundkey and a Galaxy A53 (Android 12) phone and it works perfectly!
So Soundkey is NOT the problem... it is the android device.
So I went back to the Note 8 (android 9) and installed 'lesser audioswitch' and selected USB DAC but still phone call switched over to earpiece as soon as the call connected (not to DAC) and refused to switch to DAC during the call!

 

[staticV3]

I want a DAC&AMP to use with my Android phone for music and phone calls.
I was over the moon with the Cyrus Soundkey (~17db boost)...but phone calls were going to my phone's speaker.
Will this device be suitable and loud enough?

If your phone supports calls via USB, then this dongle will work fine.
It can play 75% as loud as the Soundkey.

 

[conandrum]

If your phone supports calls via USB, then this dongle will work fine.
It can play 75% as loud as the Soundkey.

Thanks for replying friend.
It has to be at least as loud as the Soundkey, which is just perfect.
Can you suggest something better? I can't seem to find anything suitable.

 

[conandrum]

If your phone supports calls via USB, then this dongle will work fine.
It can play 75% as loud as the Soundkey.

Also, how would I know if my phone supports calls via USB?

 

[staticV3]

Also, how would I know if my phone supports calls via USB?

When you're being called and the sound comes from your USB DAC, then the phone supports calls via USB.

 

[conandrum]

When you're being called and the sound comes from your USB DAC, then the phone supports calls via USB.

Are you suggesting that the Soundkey is not my problem here?
From what you are saying, I understand that Soundkey should be able to handle phone calls, but my phone is the problem.
Are you sure?

UPDATE 20 Jan 2024
-----------------------
The reason why phone calls do not come out of the USB DAC is because the Android device does not support calls via DAC.
Just tried a phone call with the Cyrus Soundkey and a Galaxy A53 (Android 12) phone and it works perfectly!
So Soundkey is NOT the problem... it is the android device.
So I went back to the Note 8 (android 9) and installed 'lesser audioswitch' and selected USB DAC but still phone call switched over to earpiece as soon as the call connected (not to DAC) and refused to switch to DAC during the call!

 

[staticV3]

Are you suggesting that the Soundkey is not my problem here?
From what you are saying, I understand that Soundkey should be able to handle phone calls, but my phone is the problem.
Are you sure?

I'm not sure, but I don't see how a dongle could affect whether the call is being sent to it. They don't have such control.

 

[conandrum]

I'm not sure, but I don't see how a dongle could affect whether the call is being sent to it. They don't have such control.

Do phone calls work with your simple headphone dac/amp?

 

[conandrum]

UPDATE: Just tried a phone call with the Cyrus Soundkey and a Galaxy A53 (Android 12) phone and it works perfectly! So Soundkey is NOT the problem... it is the android device. So I went back to the Note 8 (android 9) and installed 'lesser audioswitch' and selected USB DAC but still phone call switched over to earpiece as soon as the call connected (not to DAC) and refused to switch to DAC during the call!

Do you know if there is a way to force call audio output via DAC?

 

[staticV3]

Do you know if there is a way to force call audio output via DAC?

I don't, sorry.

 

[Nutul]

UPDATE: Just tried a phone call with the Cyrus Soundkey and a Galaxy A53 (Android 12) phone and it works perfectly! So Soundkey is NOT the problem... it is the android device. So I went back to the Note 8 (android 9) and installed 'lesser audioswitch' and selected USB DAC but still phone call switched over to earpiece as soon as the call connected (not to DAC) and refused to switch to DAC during the call!

Do you know if there is a way to force call audio output via DAC?

Probably there is, but I believe it would be at the Linux layer of Android.

 

[conandrum]

After running some more tests and reading for hours I have a new question:
I have found out that the Samsung Note 8 comes with these USB-C earphones.

So the question arises... Why do these earphones carry music and phone calls, but the Cyrus Soundkey does not?
Is it because the Note 8 works in 'Audio Accessory Mode' when making phone calls (thus looking for a specific USB connection and rejecting the Soundkey)?

If my theory carries any weight, then this question follows:
Is there a USB DAC/AMP that can handle both worlds concurrently ie. 'Audio Accessory Mode' (analogue) and Digital Mode?
(it would therefore do the work of the Soundkey and also be able to work with phonecalls)

 

[staticV3]

Is there a USB DAC/AMP that can handle both worlds concurrently ie. 'Audio Accessory Mode' (analogue) and Digital Mode?

None that I know of.

 

[colorzpe]

Is this dongle run in UAC 1 mode ?
considering to by this one to pair with Nintendo switch

 

[staticV3]

Is this dongle run in UAC 1 mode ?
considering to by this one to pair with Nintendo switch

The 24/96 limit and lack of hardware volume control are signs of a UAC1 DAC.
Unfortunately I don't have a PS5 or Switch to confirm this 100%.