Lumin U2 mini released

Markus_Hubner · October 31, 2022, 6:46am

Ah get it.

frederic_Fongarnand · October 31, 2022, 9:33am

Hello , yes i confirm , thanks a lot !

Maruthi_Kaza · November 7, 2022, 5:29pm

@wklie - have recently picked up U2 mini and am currently using Roon and trialing Audirvana. Roon is able to recognize U2mini and play wonderfully but for some reason, U2mini is not showing up in Audirvana (am using under Win11). Can you pl suggest what could be the issue and how to resolve the same?

many thanks in advance,

wklie · November 8, 2022, 1:23am

Disable Windows Firewall.

Lumin is a UPnP renderer when using JRiver or Audirvana.

Maruthi_Kaza · November 8, 2022, 4:23pm

Thanks Peter, working fine now!

Maruthi_Kaza · November 9, 2022, 7:44am

@wklie - additionally noticed that when I use coaxial output of Lumin U2 mini, in Roon, am able to upsample only till DSD64 while when I use the USB output, the upsampling goes till DSD256. I know the coaxial/AES/toslink outputs are limited to DSD64 but why should there be a limit on the input side? Can we not accept till DSD256 on the input side and downsample as required at the output stage depending on the digital out being used (either USB or others). Pl clarify.

wklie · November 9, 2022, 8:04am

This can be done manually using Lumin internal resampling. But if you are using Roon, please use Roon DSP Engine instead to do the resampling.

By default re-sampling is off, so DSD256 input will require DSD256 output, i.e. USB only, unless you change the settings as necessary.

Alex_Simon · November 9, 2022, 8:10am

The ‘input side’ in this case should be considered as the music source (which can be up to DSD512 / PCM768). There is no point taking a lower res source, upsampling it for input to LUMIN and then downsampling again for output to DAC.

To summarise - The UPnP process is as follows:
Music source > Resampling if needed > digital output.

With Roon, it could be:
Music source > Roon DSP + resampling if needed > LUMIN (which could resample again, but pointless and discouraged) > digital output.

(edited as Peter had already replied)

Maruthi_Kaza · November 9, 2022, 9:31am

Thanks @wklie and @Alex_Simon for your replies.

Yes, am trying to upsample in Roon DSP only and then downsample in Lumin appropriately to feed the DAC.
So the scenario is as you specified:
Music → Roon DSP and upsample to the max allowed → Lumin (downsample to DAC specific) → Digital output

What I observed is when I use the coax output of Lumin, Roon can be set to upsample only upto DSD64 (its actually default/disabled at DSD64) while when I use the USB output of Lumin (by disabling all other digital outputs in Lumin settings), Roon can be set to upsample upto DSD256. In both the cases, have manually set Lumin to downsample to DAC frequency appropriately.

So I was wondering if Lumin somehow interacts with Roon and specifies the max upsampling frequency allowed based on the output downstream rather than accepting the user specified/ max allowed (DSD256) and downsample based on the settings (limited to the specific output though)

Burkhardt_Petermann · November 9, 2022, 10:23am

This doesn’t make sense in any way. You can upsample in Roon to the max, which your DAC can handle through USB or SPDIF. The Lumin device shouldn’t resample anything in using Roon.

that’s the max (with DoP), which SPDIF can handle.

this is the max, which your DAC can handle (it seems, that you’re using also DoP here). If you connect a DAC through USB (bidirectional!) to the Lumin and also Roon knows about the DAC.
On the other side SPDIF gives you not such an information.

Maruthi_Kaza · November 9, 2022, 11:24am

Thanks- am trying to evaluate various scenarios with native Roon playback vs upsampled playback and found this.

wklie · November 9, 2022, 1:48pm

Yes, by design. This way a customer who uses coax output instead of USB output, plays a DSD256 file from Roon, Roon will automatically downsample it to DSD64. No manual configuration necessary. It just works.

Lumin default setting is to not resample even when USB DAC is not connected. If it reports DSD256 capability to Roon but the user does not have a USB DAC and does not change the resampling settings, the DSD256 file cannot be played in Roon. No good.

Maruthi_Kaza · November 9, 2022, 2:38pm

Thanks Peter for the helpful replies;
My current usage is Roon or Audirvāna on a NUC streaming to U2MINI with digital output to a AN DAC (R2R DAC with max 96KHz/ 24bit capability over coaxial input only)

My intention of picking U2MINI is to be able to stream DSD and if possible upsample PCM to DSD as well and down sample in Lumin to 96/24 to suit the DAC.

What would you suggest as a best configuration in my usecase- same as above or limit Roon DSP to 96/24 for all DSD/PCM and disable Lumin downsampling?

Which of Roon DSP/ Lumin resampling would be superior SQ wise?

Thanks

wklie · November 9, 2022, 2:39pm

Whenever you use Roon, disable Lumin internal re-sampling. Use Roon DSP Engine instead.

I think Audirvana is capable of resampling as well. In that case, use Audirvana instead of Lumin internal re-sampling.

John_Raimondi · November 30, 2022, 2:38pm

Does the PS Audio Directstream DAC limit the power of the Lumin U2 Mini? It appears that the usb connection on the Directstream DAC is maxed out at DSD 128. The Lumin U2 has the potential to go to DSD 512. I’m using Roon to control my music.

killdozer · November 30, 2022, 3:18pm

The PS Audio site has the answer, over USB:

I2S, and USB — 44.1kHz to 352.8kHz 16bit, 24bit, DSD 64, DSD 128 (I2S DSD 256 with Sunlight update)

so limited to DSD 128 over USB. DSD 256 is possible using I2S with an update applied.

wklie · November 30, 2022, 4:10pm

That is correct. You can play up to DSD128 when using this DAC with Lumin USB output.

John_Raimondi · November 30, 2022, 4:25pm

Thanks,
John

Koen_Vingerhoets · December 1, 2022, 12:41am

Waw - what a thread with a wealth of info. Thanks @wklie for answering so many questions.
I’m afraid I’m going to add another one.

I have a USB flashdrive with DSD files (ex Beethoven’s 9th in DSD 256 2ch). I’m running a T+A MP 3100 HV (it has a “USB DAC” connection) and a PA 3100 HV. I’m an avid Roon user, my entire flac music collection is in the basement on a NAS.

I’m looking for an efficient way to play these DSD files. I’ve read elsewhere in this thread people used T+A device with the Lumin. You said earlier that a “USB DAC” connection should work up to DSD512 if it accepts native Linux input. From the MP 3100 HV manual : “With Linux operating systems the playback of DSD streams up to DSD512 and PCM streams up to 384 kHz is possible.” So that seems ok.

I’ve noticed the two USB ports on the Lumin U2. After reading the manual and most of this thread, I failed to understand if I can use one port for a USB Flashdrive (or SSD / M2 if required) AND at the same time use the other USB port as output for the “USB DAC” of the MP 3100 HV.

If not, I guess I’ll have to start looking for a full DAC that I can connect to my amp.

Thanks,
Koen

wklie · December 1, 2022, 1:41am

If it’s possible to hook up the MP 3100 HV to a Windows computer via USB, please tell me the USB VID and PID values in its Windows driver properties. So I can check whether we recognize it as native DSD compatible. Even if it is recognized, there is a chance you may need to upgrade its USB DAC firmware.

USB storage devices connected to Lumin cannot be seen by Roon.
Some SSD could require higher current than the standard 0.5A Lumin delivers over a USB port.

Please connect the USB storage device to the Roon Core computer instead.