Lumin U1Mini - Leedh + Luxman L-509X

@wklie Hey Peter, I have the Lumin U1 Mini > USB to Holo Audio Spring 3 KTE DAC > Luxman L-509X integrated amp. I started using Leedh volume control today, but my Luxman manual does not mention the unity gain. I can use the Luxman as a dedicated amp, but that requires an RCA cable and I prefer using XLR from my Holo Audio DAC. So, is it proper to set the Lumin Leedh volume to 99db and control the volume with my Luxman integrated amp? I use my Lumin as a Roon endpoint and I noticed Leedh showed up in the Roon signal path! I prefer to use my integrated amp volume control, but the Leedh volume control sounds incredibly good! So, is there a detriment to the Leedh volume control by setting it to 99db and using my integrated amp volume control?

Thanks in advance!

have you tried using fixed instead of device volume for the endpoint?

Screen Shot 2022-02-07 at 7.42.21 PM

I had it set on fixed since I’ve been using Roon for several years and since I’ve owned the Lumin for about a week. I’ve found that Roon SQ is inferior to using the Lumin with its native app. So, I turned on Lumin Leedh volume control, which allows the user to use with Roon and it sounded extremely better than using Roon in fixed volume with the Lumin. I’m just focused on the best way to use the Lumin Leedh volume control. A Lumin representative should be able to assist me with this question.

Lumin volume max is 0dB. If you mean volume 99 out of 100, it means -0.5dB.

  1. If you have multiple sources connected to the L-509X, then you have no choice but to use the preamp volume control, and keep the Lumin volume control turned off.

  2. Otherwise, you may keep the XLR connection from the DAC, turn down the Lumin volume to a very low value, and turn up the preamp volume.

  3. Alternatively, use the L-509X as power amp only, this necessitates the RCA output from the DAC. Again turn down the Lumin volume to a very low value, and turn up the preamp volume.

With a free sound meter app in your smartphone to equalize the volume, play some tracks and find out which out of the 3 sounds best to you.

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That’s a little confusing because my Lumin Leedh volume control is from 0 - 100dB, with 100dB being maximum volume. Maybe the European Lumin models Leedh volume controls are from 100 - 0dB? Or, technically, 100 - 0dB maybe the actual volume setting, but it does not display that way with my Lumin. As I increase the Lumin Leedh volume up, the numbers increase from 0 - 100dB.

For clarity, I want to use my integrated amp volume control with Leedh while using Lumin as a Roon endpoint. So, the Lumin user manual instructs the user to either determine the preamp unity gain or connect directly to a power amp and conduct Leedh volume control with the Lumin. I can’t find the unity gain for my Luxman.

Will I still get the full benefits of the Leedh volume control technology by setting the Leedh volume to a fixed dB and manage the volume with my integrated amp? Remember, I am using the Lumin as a Roon endpoint, exclusively, and using Leedh simultaneously because I like the Roon interface better than the native Lumin app. Also, we have (3) volume controls in play;

  1. Preamp volume
  2. Leedh volume control
  3. Lumin app Max. volume

What volume do you recommend for the Lumin app Max. volume?

Thanks in advance!

See picture below.

It’s 0-100 steps, not 0-100 dB.

Luxman unity gain is achieved by the power amp RCA input with SEPARATE function.

Cases where this makes sense are: 1. the system had too much gain or 2. the DAC exhibits intersample overs clipping.

If you have bypassed the preamp (i.e. configuration 3) and exclusively use Lumin volume, then find the most quiet music track you listen to (perhaps some classical music), gradually increase the volume until you’ve reached a volume you think you’ll ever need. Add a slight margin, then that’s the Max. Volume % you need for speaker protection.

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Only there is a limitation. If the output of the DAC is from the MQA, then the Leedh volume does not pass it and the DAC does not decode it. I checked on my L-505 and D-03X, using Leedh on Luxman in this configuration is not effective. The sound quality of the stream is optimal without it.

@wklie I appreciate the detailed response as I have concluded most of what you have explained after researching everything last night!

I will experiment with all volume settings because I have settled on using my integrated amp as the master volume control. I have my home theater (HT) surround processor connected to the Luxman RCA inputs to use the Luxman as SEPARATES, so the Luxman unity gain is being used for the HT setup.

Big question for you; does Lumin have any plans to upgrade/update the native Lumin app with a better cataloging system? Something on par with Roon or Aurender. I wish Lumin didn’t have to use the Minim Server because that’s more software I have to download and integrate in order to have a better experience with the native Lumin app. It would be better than the Aurender offerings because Aurender cannot be used as a Roon endpoint. I think an exclusive Lumin cataloging software already built into the Lumin app would be a great idea. Get rid of using Minim Server! Lol…

Thanks for all your help Peter!

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I don’t have any MQA files. I don’t have a Tidal subscription, so I haven’t experienced many MQA files except one time I came across a tune using it in a Qobuz stream while I was using Roon. I learned that about two (2) record labels use MQA and Qobuz streams their music, so that was my only experience with MQA. I like the benefits of Leedh technology so far in my setup.

I did not hear a difference when using Leedh. I think that the use of algorithms that are not needed in this case leads to sound degradation. But if you like it, use it. :slightly_smiling_face:

Using your integrated remotes volume control seems like you are defeating the purpose of LEEDH. I own a T2 and use LEEDH with my PrimaLuna integrated. I completely bypass the preamp circuit with the home theater out. My only source is the T2. I can no longer use the PrimaLuna remotes volume control function. I use the Roon or LUMIN app volume slider icons on my IPad controller. Not a big deal for me. I agree the LUMIN app sounds more transparent than the Roon but it is close.

You are correct, but I just don’t like using the Lumin volume control on my iPad. I have my Lumin Leedh volume set at 70 and the difference between the SQ using the Leedh volume control vs. Luxman + Leedh volume control is not a night and day difference, although it does sound a tad bit better. I may change my mind. At least I have the option.