Digital Audio Outputs Request on U2 mini

Recently purchased Lumin U2 mini and found out that the USB digital output can not be switched back and forth between other digital outputs.
I have 3 DACs, Chord TT2, Denafrips Potus II, and Merason Frerot. I also have Titans Audio Lab Helen jitter reducer/signal enhancer. I used to connect USB to my Chord and Coaxial Spdif to Titans Helen then to Denafrips and Merason with other streamers. I was able to enjoy the different sound signatures from these DACs conveniently. It’s like using 3 different cartridges with my 3 turntables. However, with the U2 is much more difficult that I have to plug or unplug the usb cable from the back of my TT2 in order to enjoy my musics.

The outputs are independent of each other, as you’ve discovered, as far as I know there’s no internal switching facility to divert the input to a different out. I’m guessing lead swapping is your only option without an external switch. Peter @wklie may know of another option…

Thanks for the quick reply. My other streamers, Auralic Aries and Ifi Zen stream which I still own are able to switch USB and other different digital out from their apps without plug or unplug the physical cables. I was hoping Lumin could add the feature for the U2 mini. Even though on Lumin website under “Digital Audio Output Setting” in the Lumin manual mentioned that “On some LUMIN models with multiple Digital Audio Output Ports, each can be turned on or off here.” Unfortunaetly, It does not specify which models can not turn on and off the USB digital out.

Hi Ken, you can disable output on the U2 mini, see screenshots…

I’m adding a new feature that allows SPDIF to be used without unplugging the USB cable - this requires a firmware and app update.

Do you use an Android device? Otherwise the iOS app will have to wait for a public release.


Many Thanks.

I am mainly using the Android device.

I’ll prepare a new firmware with this prerelease feature and corresponding Android app for you.


Great support and service !!!

Now I can sell my Auralic Aries and IFi Zen Stream and keep Lumin U2 mini only because it sounds better than the other two.

Thanks !!!

Prerelease U2 Mini firmware and Android app for USB / SPDIF mode setting sent to your PM.

This allows you to force SPDIF output even if USB is connected to another DAC.

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Got it. Many thanks

Hi Peter,

I am planning to upgrade U2 mini to T3.
Can I use both analog outputs at the same time, rca out to preamp and xlr to headphone amp?


Some DAC manufacturers prefer the user to use xlr output instead of rca such as Denafrips Pontus II. Does the T3 design also prefer the user to use xlr?


As long as you’re not creating a ground loop, this is usually fine for T3 T2 D2 D1.

If on X1 P1 S1 A1 T1 (with Lundahl transformers) simultaneous analog output connection will decrease SQ.

Yes, XLR is generally recommended for Lumin analog output regardless of model. However, you may A/B compare it with RCA output (with a sound level meter app on smartphone to attain equal volume) and see which sounds better to you in your setup - especially the preamp.

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Thanks and best regards


Another customer pointed to this thread referring to this as a bug.

I’d like to clarify that this is not a bug. This is by design - Upon detecting presence of a USB DAC, non-USB outputs are disabled.

This is not a bug fix. This feature is ready in form of a beta firmware. Customers who need this please contact me.

With this beta firmware (not a public release) and the app update (already released), there is now a “USB / SPDIF Mode setting” in Lumin app for U2 (Mini) / U1 (X / Mini)

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Thank you for the update.
What is the new app version?
My app is 5.4.0 and the firmware is 15.3.

Lumin Android app 5.5.0 and iOS app 8.6.0

Firmware 15.4 is released to include this feature.

Apps are also updated.


Received !!!

Upgraded and works great !!!

Thank you for your help !!!