Question on U1 and U1 Mini

OK thanks. I know my use case is likely unique :slight_smile:

@wklie -

I intend to feed 2 DACs via a Mutec-3.

I want to feed the Mutec-3 with AES out of the U1 Mini and then feed my DACs with USB and COAX out of the Mutex. Of course, the DACs’ outputs will be into a pre-amp.

As far as the U1 Mini is concerned, will that be a problem?

Thanks

I assume you mean the MC-3+USB. If you only stream up to PCM 192kHz and DSD64 (DoP) from the U1 MINI, AES connection to the MC3-+USB should be ok. For higher than these rates, it won’t be possible via AES.

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Yeah, got lazy when I posted. I’ve had the Mutec for about a year, mostly for its ability to change formats and to simultaneously output to multiple ports.

Currently, I either run bit perfect or let my iFI Pro upsample to DSD1024 or 702/768, depending on my mood.

The DAC I’m going to pull the trigger on is a PrimaLuna Evo 100, which is only good for DSD128(DoP) or 192/24. So no real problem with the U1’s AES output.

Wanted to follow-up on my earlier question. I received my U1MINI and am pleased to say it works perfectly in my system. With both DACs connected to the 2 USB outputs the U1MINI only outputs to the one in Roon that is powered on. The other unit can be in standby without issue. Exactly what I was hoping for with no cable swapping needed! The U1MINI also sounds SIGNIFICANTLY better in my system than directing the USB outs from the Roon Nucleus+ directly to my DACs. Overall very happy with the upgrade. I need to start a U1 upgrade fund :slight_smile:

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A question for you,

  1. I found when playing Hi-Res files that when the volume of my dac/preamp is low I hear a lot of noise to even distortion, now I have been able to solve this by setting the Simple Rate Conversion to Enable in Roon, I find this strange.

  2. Is it disadvantageous to have the Lumin U1mine connected to the dac/preamp with both AES/ EBU and USB or should I not do this?

  1. If this happens with both AES (USB disconnected) and USB (AES and others disconnected), please consult with your DAC manufacturer. What DAC (Atoll?) and what target sample rate are you using?

  2. When using U1 MINI AES output, please disconnect USB first.

The strange thing is that it only happens with hi-res (24-96) and / or mqa files

That’s indeed strange. Please try the various outputs of U1 MINI individually (with unused output disconnected). If it’s still the same, please connect the DAC to the Roon Core directly, bypassing the U1 MINI, see if it still exhibits the same issue.

I don’t think I have the necessary cables at the moment. I will soon talk to the dealer, maybe I can take other Atoll Dac300 and listen what it does

Dear Peter @wklie,

I have 2 questions:-

  1. when I play DSD256 files via ROON, the Lumin U1 doesn’t play any track it just skips the tracks. But if I Set DSP to convert the DSD to PCM, then it plays.

  2. When I play DSD128 the Lumin U1 Converts the DSD to 352.8KHz PCM, but plays instead of skipping the tracks.


    Is the conversion because of the volume control?

    Regards,
    Tushar.

Which DAC are you using?
Why are you set Lumin streaming to on?

I’m using Denafrips Terminator Plus. The lumin streaming is set to ON by default (I can switch it off, if it helps. I honestly don’t know it’s purpose anyways :slight_smile: ), and the DAC is connected via USB to U1.

Yes, to deliver DSD you need to disable volume control in the LUMIN settings.

Do you use Tidal or any other MQA encoded music? If not or you unfold MQA on the Roon core, you can also set “MQA mode” to “Off”.

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Thank you for the info. I just figured that out with a loud boom from my soeakers… That is a real bummer. I have Buchardt A500 active speakers, Hence the volume control from Lumin. Would have loved the T+ DAC do the conversion

Ouch! Yeah, you had it dialed down quite a bit. Well, now you know how loud your speakers can be. Gets the Adrenaline running…

Great system btw.!

I also have active speakers, and my DAC has a good volume control. Still I prefer the sound of the impedance matching and volume control from my analog preamp. But the “truth” is only in the personal listening on your system, in your room. I hope you find a good solution.

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Unfortunately, T+ do not have a volume control, so LUMIN U1 is my other efficient option. Further, I noticed when I set the DSD to PCM conversion Active in ROON DSP (which is my option to play DSD files), the DSD256 track skips to next track after playing for few sec, and I get the below error. @support @dylan @wklie would you have any suggestions…

image

Your core is under too much load converting that to PCM It’s not up to it Your processing speed is 0.6 anything below 1.5 is bad 0.6 will result in dropouts and other issues. What’s your core on. Try enabling parralize sigma Delta in the DSP resampling section it might help a bit but your core looks under powers to convert DSD at that rate.

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You can see your processing speed is 0.6 --> Server to weak for your processing.

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The unit is ROON N+… :slight_smile: