Thread: Lumin, Leedh’ing the way

Originally Posted by greyowl07

I would like to acquire the Lumin U1 or X1 & use the Leedh processing volume control (no pre-amp). Is it possible to use a hand held remote for volume in such a set-up? The remote would be for an external Dac or the Dac within the X1 (if available). If not, how does the volume level control within the Lumin app compare to a hand held device? Thanks.

You can either use the volume control from within the Lumin iOS/Android app or get the optional Lumin IR control package.

Yes.

The (separately purchased) Lumin IR remote package has a USB receiver to be plugged into the Lumin transport or player.

On receiving a volume command from IR remote / Lumin app / Roon / Tidal app / Spotify app / AirPlay / UPnP app, the Lumin transport or player applies Leedh Processing Volume. If it is a transport for digital output, the volume is done digitally and the output bitstream reflects that. This volume-adjusted bitstream is sent to the DAC.

By the way, on Roon forum there are multiple Hegel users with Lumin T2.

No problem.

From Lumin + Leedh Digital Volume control - Digital Sources, DACs, and Computer Audio - StereoNET International

I have a PS Audio BHK Signature preamp which I thought just “wasn’t right”. I placed it on Unity Volume (77) and turn on Leedh Volume on my U1 Mini. The change was so much more significant than I would have thought! When I tried initially running my DAC directly to the power amp, it sounded thin. Now it’s running through a proper preamp with all its input gains and transformers, the sound is full, voices clear and trebles have lost the brittleness. WOW!

If unity gain is not specified in the preamp manual, please turn up the preamp volume, and turn down the Lumin Leedh volume. However, if you also use the preamp for other sources, then you must turn down the preamp volume before you switch to other sources, otherwise there would be a risk.

Yes, the Lumin volume in Roon is done using Leedh processing. In the next firmware you'd actually see "Leedh" in the Roon signal path.

Lumin Firmware 15 added analog output balance control to our models with ESS DAC chips (X1 P1 T2 S1). To the best of my knowledge, we are the first manufacturer that makes of use Leedh Processing Volume to provide balance control.

Thx Peter.
Am I the only who can’t find the setting after upgrading the firmware?
App is up to date as I write this.

Android app has already been released. iOS app is waiting for Apple approval.

That would explain it. Thanks Peter.

Upgraded the iOS app. L/R balance controls are there. X1 just went up a notch on creature comfort capabilities. Thanks Lumin team!

Originally Posted by Low325

Upgraded the iOS app. L/R balance controls are there. X1 just went up a notch on creature comfort capabilities. Thanks Lumin team!

Peter, has the iOS app been approved? My app is not updated.

Originally Posted by Audiofan57

Peter, has the iOS app been approved? My app is not updated.

Ignore above. App was updated today.

Nice feature. Will come in handy for those times the dog decides to take over the sweet spot.

Thanks Lumin, for continuing to improve your product.

So the balance control is only available on units with ESS DAC's?
Not available on units like the U2 mini even though they have Leedh volume processing capability?

Originally Posted by jadedavid

So the balance control is only available on units with ESS DAC's?
Not available on units like the U2 mini even though they have Leedh volume processing capability?

Balance control is only available on X1 P1 T2 S1, and only when using the analog output.

Originally Posted by timindy

After reading a bit on the LEEHD feature I decided to try running my D2 (balanced) directly into my Benchmark AHB2 amp. Although I'm only a couple album listens in, it sounds very promising. I just want to clarify my settings as the best way to use it. In settings on the app, I have the volume at 100%, and use the red circle to adjust volume while listening. The indicator in the red circle is anywhere from 45 to 65, depending on how hot the recording is. Is this the optimum way to use it? Thanks.

It's completely up to you.
You could also set the max volume to 65 (or 70 to give you a little headroom) and then use the circle to go up to 100%. This gives you slightly more granularity of control.
The sound quality is the same either way, but this way limits the volume to protect your speakers and then gives you 1-100% control up to that limit.

(The main volume control will still allow 100 positions of adjustment, but now the actual volume = main volume × Max Volume %. For example: if the Main Volume is 80, but the Max Volume % is 70, then the actual volume is 80 × 70% = 56.)

The remote volume button repeat rate is tuned in a way so that it'd be safe. We don't want the button being held accidentally to quickly cause potential harm to the speakers.

This is one of the most in-depth comparison of ESS DAC chip volume against Lumin enhanced implementation of Leedh Processing Volume to analog output.

In The Absolute Sound issue 330 (Sept 2022) review of Lumin P1:

It is easy to turn Leedh on and off in the app to compare it to a conventional digital-domain volume control, as well as to no volume control. When the volume is set at “100” or the output level is set to “fixed,” both Leedh and the conventional volume controls are bypassed.

When I applied 30dB of attenuation with the conventional volume control, an entire level of low-level detail was shaved off. There was simply less musical information there, from quiet sounds at the back of the mix to the inner detail of instrumental timbre. Percussion instruments sounded like nothing more than transient clicks, the mechanism by which the sound was created was lost. On Norah Jones’ debut album, her voice was harder and a bit coarse with the conventional volume control, and was overlaid with a roughness and stridency, particularly on louder passage in the higher end of her register. When I switched to the same amount of attenuation with Leedh, the sound became more liquid and refined overall, with the low-level detail restored. The bite on the leading edge of the guitar was gone, replaced by a more natural rendering of the instrument’s attacks and dynamics. With Leedh, Jones’ voice became more immediate and palpable, with a human quality missing from the mechanical rendering I heard with conventional digital-domain attenuation. Finally, unlike the conventional volume control that flattened the soundstage and reduced the sense of air, Leedh maintained the presentation’s three-dimensionality and bloom.

I then compared 30dB of Leedh attenuation with no attenuation by making up the volume difference with the CH Precision L10 preamplifier. To my surprise, I heard no degradation with Leedh; the two presentations sounded identical (the L10 was in the signal path for both presentations). It was clearly obvious that this amount of attenuation in a conventional digital volume control was a non-starter sonically, and that Leedh is sonically “lossless,” as the company claims. This is, to say the least, a significant achievement.

I suggest you ask WestminsterLab first.

Originally Posted by Arif

I am thinking of introducing an active crossover (Bryston 10B-Sub) in between the X1 and the Rei. I am wondering if this is even possible to do and also concerned if there is any risk involved?

That's generally how the 10B-Sub would be inserted into the chain: after volume control and before your subwoofer(s) and stereo amplifier. I've set it up this way before. The input impedance on the Rei is listed at a healthy 200 kOhm. The 10B input impedance is stated as 20 kOhm but was measured higher by Stereophile, and is an active input stage so I expect it will be a flat input impedance and fine with the X1's output transformers.