Lumin X1: Enabling an Even Simpler Yet Better Sounding System

lscangus

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Oct 24, 2018
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Are there any gains on sound quality if i.e. Roon is bypassed?

Roon uses a different protocol to stream music from the Core to the Client when compare to UPNP. Also the additional function of the LUMIN systems increases the load of the processors, additional loading means more noise may be generated. Be experimental and share with us your findings!
 

AMR / iFi audio

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Roon uses a different protocol to stream music from the Core to the Client when compare to UPNP. Also the additional function of the LUMIN systems increases the load of the processors, additional loading means more noise may be generated. Be experimental and share with us your findings!

Hmmm, interesting and makes sense. Once we'll have our hands on one of Lumin devices, we will It's difficult to discard Roon once one gets used to it!
 

lscangus

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Hmmm, interesting and makes sense. Once we'll have our hands on one of Lumin devices, we will It's difficult to discard Roon once one gets used to it!

Is not a matter of choice I think, as Lumin support both all at the same time on the fly. So customers get to choose when to use RAAT( ROON ) or UPNP to stream their music. Which model are you getting ?
 

lscangus

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It's going to be either U1 or U1 Mini. No need for DAC inside.

Then I would really recommend the U1 with the X1 power supply. If you are using the USB Audio output to the DAC, X1 is also a very good choice.
 

lscangus

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How much of a difference that external PSU makes?

The difference is substantial enough that I once did a demo at a clients setup in Singapore, he made up his mind in less than 30 seconds. One can notice the much reduced noise at the background, and the increase in micro dynamics.
 

AMR / iFi audio

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The difference is substantial enough that I once did a demo at a clients setup in Singapore, he made up his mind in less than 30 seconds. One can notice the much reduced noise at the background, and the increase in micro dynamics.

That's what I expected. Clean power should translate do less noise. Thanks!
 

tmallin

WBF Technical Expert
May 19, 2010
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In post #17 above, I said:

In addition, for best sound from the Lumin's native functions I recommend turning off the Re-Sampling settings unless you are actually using the Lumin's upsampling/resampling features. With Re-Sampling set to Custom, first set all resampling choices to Native and then turn off Re-Sampling. I generally do not find Re-Sampling to improve the sound I hear from most program material via the Lumin X1. The sonics are changed, yes, definitely, but I do not generally regard those changes as improvements--you may disagree. In general, upsampling/resamping trades off an increased feeling of general openness/spaciousness against less specific/focused imaging and less bass and more treble--a more lightweight tonal balance, in other words. The LAST thing that most digital sources need in most high-end systems is less bass and more treble.

I have to recant on this, at least partially. I now recommend experimenting withe the upsampling/resampling.

Extended listening comparisons have shown me that, especially with low-bit-rate internet radio programs, upsampling/resampling 44.1 kHz programs to 176.4 kHz makes an overall positive difference. Yes, the bass can still be less potent, but it is clearer and more defined, as is the midrange and highs, plus the imaging is at least as focused while the staging is more expansive and defined both left/right and front/back. The backgrounds are also blacker.

Actually, recently I've been doing most of my listening with the resampling on. For those functions native to the Lumin (playback of my own music files, Qobuz, Tidal, Spotify, and internet radio via Tune-In), I generally prefer the sonics of the maximum PCM resampling setting of 384 or 352.8 to any of the lower PCM settings or the DSD 64 or 128 resampling. This is so even with 24/192 programming from Qobuz, and for the same sonic reasons mentioned above.

For internet radio stations played back via AirPlay (Lumin Streaming) from my iPad Pro I must limit the resampling to 176.4. The highest 352.8 setting, for some reason, yields an odd stuttering or motorboating distortion. Neither of the DSD resampling levels have this distortion, but I prefer the sonics of the 176.4 resampling to the DSD 64 or 128 choices.
 

tmallin

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May 19, 2010
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As I write this, my current system is Lumin X1 using its digital volume control > pair of bridged-to-mono Benchmark AHB2 amps > Gradient 1.4 speakers. I use an iPad Pro to control Roon and the Lumin app. The Roon core (which also hosts my music library and MinimServer) is a general purpose computer, albeit a powerful one: Dell XPS 7760 AIO Signature Edition with Intel Core i7-7700K CPU at 4.2 GHz with 64 GB RAM running Windows 10 64-bit.

As I've said before, computer audio is certainly fascinating. When I last wrote about Roon, it was back in August 2019 in my thread dealing with the Lumin U1 Mini + SBooster Power Supply, post #8. There I said, about Roon in comparison to the Lumin App:

Roon may offer a yet-slicker interface than the Lumin App if you need/want one. I've just downloaded the trial version and began to use that over the last weekend. Talk about being able to go down a musical rabbit hole! Roon opens possibilities for musical exploration I never dreamed about before, but I'm not really sure the audiophile in me needs this level of musical inter-relatedness.
Sonically (with the exception of the DSP equalization opportunity Roon affords!), the Lumin App is at least as good if not better in my setup, so the differences so far are purely how the music is organized and inter-related. I probably will comment further on Roon after I get more experience with it. Many music lovers swear by Roon, but already I can tell that it is not really classical music oriented in terms of the "deep knowledge" it offers.


Roon recently released a new version, Version1.7 build 537. I installed that update a few days ago. I agree with other WBF comments about this new version. This is a significant and very worthwhile sonic upgrade. While the Roon interface already was the best, previous to this update, I regarded the sonic quality of Roon in my system as at least a bit bright/edgy and less three-dimensional compared to that of the Lumin App fed via MinimServer. Now, after the update, while the Lumin app still sounds slightly better, the difference is much less, so much less that the superiority of the Roon interface would probably make it my "go-to" for all but the most serious of listening. I put my money where my mouth is and converted to the Roon lifetime plan from the annual plan, shelling out $700 to do this.

In addition, as one review of Roon's Nucleus+ has mentioned, Roon's upsampling/resampling function sounds exceptionally good. It does not add brightness or reduce bass. The general tonality remains very natural with the highs gaining added clarity, the background added blackness, the staging size in all dimensions, and the imaging added roundness with equal stability.

I have experimented with various levels of Roon's upsampling/oversampling. Since the Lumin X1 accepts PCM inputs of up to 768 kbps and 32 bits, I tried all the levels up to that maximum, which is Roon's maximum offering. Generally speaking, the more upsampling of 44.1k or 48k material, the better sounding the result with the new Roon build.

Even with this level of upsampling/resampling, Roon is telling me that the available processing is at a level of about 9. Apparently, as long as your available processing level is above 1, you have sufficient computing power to perform the requested processing. As expected, if I cut back the oversampling/resampling to 352.3 or 384, the processing available is at twice that level, 18. With 705.6 or 768 upsampling/resampling, I can still watch Netflix HD movies on the same computer with no problem. My computer's Task manager indicates that with Roon doing 705.6/32-bit upsampling/resampling, Roon is taking about 2% of my computer's CPU capacity.

At least for the time being, I am now using Roon as my go-to music streamer. It's definitely the slickest interface and now it also sounds at least as good as the Lumin App.

When using Roon, I have the Lumin App settings with the Lumin App's Roon Ready and Lumin Streaming (aka AirPlay) functions enabled. With those settings, the Lumin App can be turned off. My iPad controller can then use the Roon app to select music and control the volume. Any streams which Roon cannot natively handle (e.g., Sirius/XM or Jazz Radio) can be selected from an app on the iPad or from a Safari bookmark on the iPad. These sources then stream to the Lumin via AirPlay/Lumin Streaming from the iPad. With this configuration, the Roon volume control controls all streams, even the AirPlay/Lumin Streaming ones.

Interestingly, as long as the Roon Core is operating (as in the Roon program is open or minimized on my computer desktop), then neither the Lumin App nor the Roon App needs to be turned on on the iPad controller. The music continues to stream. The iPad can even be powered down--same result. The volume and program choices (except for AirPlay/Lumin Streaming) can be adjusted and controlled from my desktop computer. Thus, if I'm working at my computer desk (as I am now) and just want my primary audio system to play background music, I can control the volume and streaming program for the audio system in the other room from my Roon Core computer desktop.
 
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lscangus

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Oct 24, 2018
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Thank you so much for everyones sharing. A bit of insight related to the findings regarding to LUMIN's open home VS roon RAAT. As most of you know, these two different protocol of streaming music through the network. OpenHome is basically UPNP, where the LUMIN app ( or any OpenHome controller ) will send a specific location to the LUMIN player for the LUMIN player to fetch the file from the server across the network. The Roon RAAT is a bit different, the core will see the LUMIN as a target, where streams of audio signal will be sent to the LUMIN player by the core. We ( Lumin ) observed a different usage ( loading % and pattern ) in both network and CPU time between the OpenHome and RAAT.
 

tmallin

WBF Technical Expert
May 19, 2010
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I can now heartily recommend the Roon software and the Roon Nucleus+ (Plus) as a server. Yes, I took the full Roon plunge (or at least a much fuller plunge) and purchased the Nucleus+, moving my music files and serving off my general-purpose computer. I now have my music files on a 1TB Patriot Supersonic Rage Elite USB 3.1 stick inserted into one of the two USB ports on the back of the Nucleus+.

As I've noted, previous iterations of the Roon software sounded a bit bright and edgy to me in comparison with the same music files sources from my networked computer, Tidal, or Qobuz played via the Lumin App through my Lumin X1.

With the latest iteration of the software and firmware, however, those objections have disappeared. Now there is no sonic impediment to enjoying the superior Roon user interface and metadata. My move to the Nucleus+ as my music server has only served to reinforce my evaluation of Roon's current sonic presentation. Moving to the Nucleus+ resulted in more solid and defined bass, greater overall clarity and relaxed/analog-like quality of the entire presentation, as well as better imaging and staging. I don't hear any downsides.


Plus, moving the music serving off my general purpose computer frees up that computer's memory and CPU load Roon's serving and resampling was presenting. That computer now offers even faster performance and better HD movie streaming quality, both for video and audio.

With the Nucleus+ as server, I believe the maximum PCM resampling levels (705.6 or 768 kHz/32 bit) provide the best sonics feeding my Lumin X1. The Lumin X1 is one of the few DACs which accepts that bit rate and depth. I could also stream DSD up to 512 into the Lumin from the Roon's resampler, but, to my ears, high-bit-rate PCM resampling sounds better than resampling to DSD, either via the Roon's resampling or the Lumin's built-in resampling of PCM to DSD.

In addition, for a "throw in" with the purchase of the Roon software, you get a powerful suite of DSP. I have not explored the parametric EQ DSP yet, but the upsampling/resampling functions are the first such which I've found to be all to the good, especially for 44.1/16 or 44.1/24 material, from internet radio through CD quality material.

The cost of my Roon investment is not low, at $699 for a lifetime Roon subscription and $2,500 for the Nucleus+, but that total is less than some high-end one-meter cables, so you be the judge.
 

tmallin

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May 19, 2010
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In the post above I said:

With the Nucleus+ as server, I believe the maximum PCM resampling levels (705.6 or 768 kHz/32 bit) provide the best sonics feeding my Lumin X1. The Lumin X1 is one of the few DACs which accepts that bit rate and depth. I could also stream DSD up to 512 into the Lumin from the Roon's resampler, but, to my ears, high-bit-rate PCM resampling sounds better than resampling to DSD, either via the Roon's resampling or the Lumin's built-in resampling of PCM to DSD.

Further listening via the Nucleus+ has caused me to change my mind about the DSD resampling. Resampling via the higher DSD rates (256 and 512) sound smoother in the mid and high frequencies, more analog like, yet equally detailed when compared with the highest PCM resampling levels. A/B comparisons of various resampling options have led me to use the DSD 512 sample rate conversion with 7th order CLANS DSD processing settings. I have enabled "Parallelize Sigma Delta Modulator" but I do not "Enable Native DSD Processing" both because I don't have any native DSD program material and because I think it sounds better not to enable this function.

But I have also noticed that with the Nucleus+ I now often find MQA recordings on Tidal to be at least as good sounding as the best high-res PCM version of that recording on Qobuz. Roon does not resample MQA recordings so with MQA recordings on Tidal none of Roons resampling choices are available. The MQA version sonically differs from the PCM in somewhat the same way that DSD resampling differs from high-bit-rate PCM resampling. The MQA sounds warmer, more relaxed, more analog-like. High-Res PCM recordings on Qobuz still sound more detailed in the mid and high frequencies (whether or not DSD resampling is applied to them), but by comparison to the MQA version on Tidal, the high-res PCM versions on Qobuz (DSD resampled by Roon or not) sound just a tiny bit bright and edgy. Unlike DSD resampling, MQA seems to warm up the lower frequencies and mids a bit, adding yet more analog-like warmth to the sound. But I admit that these judgments might be different if my current Gradient 1.4 speakers were balanced more warmly--say like my prior Harbeth M40.2 speakers were.
 

tmallin

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In the Darko Audio review of the Roon Nucleus+, reviewer Steven Plaskin said:

While the Nucleus+ comes with its own SMPS (Switch Mode Power Supply) that is rated at 19v / 3.42 amps, substitution of the power supply with a quieter SMPS or linear power supply can enhance the overall performance of the server by adding less noise to the overall system. I tried a 200-watt HDPlex linear power supply and an SOtM sPS-500 (SMPS) to see if there were appreciable improvements observed in sound quality. I found the HDPlex to have the best sound in my system with a general reduction in overall ‘brightness’.

Other comments on the Nucleus and Nucleus+ sound quality have also mentioned improved sound quality when the stock SMPS is replaced with a suitable linear power supply. Roon itself does not deny this effect, but I don't believe recommends a specific linear power supply at this point. Favorable comments about the after-market power supplies from Keces in both the Roon and Lumin online communities led me to order the Keces P8 model which costs about $700, including express shipping from Taiwan.

The Keces P8 arrived only a few days later at my Chicago-area address even over the Memorial Day holiday--impressively fast order processing and shipping. The packaging was bulletproof and the unit itself appears handsome and extremely well built. It's 8-amp output is fully twice the rating of the stock power supply. I did need to use the included adaptor on the Nucleus+ end of the DC cable since the Roon device has a larger center pin on its DC power receptacle than does the Keces.

While the unit has only been in my system for less than 24 hours at this point and thus further break-in may well occur, I already feel confident in recommending such a linear power supply to users of the Nucleus+. From the first couple of seconds of play, with the Keces P8 stone cold, the background took on a greater "blackness," the bass was enhanced in punch and definition, the soundstage gained size in all dimensions, imaging was yet-more focused and three-dimensionally rounded, the mid-high frequencies were definitely less edgy-bright while the very top was airier. These sonic improvements were not of the extremely slight variety, but were quite apparent and significant.

Yes, the price may seem high. But the substitution of a good linear power supply for the stock SMPS makes a shocking improvement in the already excellent sound quality of streaming via the Roon Nucleus+ in my system. I'll add further comments below if further warm-up/break-in reveal additional sonic improvements.
 

tmallin

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The quality of sound available from Roon--and indeed straight from my Lumin X1 streaming DAC via the Lumin App (and all other Lumin streamers) just took a leap up. Lumin has just incorporated Leedh volume control processing in its new firmware which I just downloaded after its release today. It's version 13.0, dated June 3, 2020. It's a new day for digital volume controls!

This algorithm claims to be a lossless form of digital volume attenuation. This is just what a system like mine, which relies on the Lumin X1's digital volume control directly driving my Benchmark AHB2 amps--needs. For information about this development from a French company, see this Darko Audio write-up as well as Lumin's own statement here.

Roon verifies in its DSP signal path flow chart that the signal going to the Lumin via Roon is being processed by a DSP volume control in the Lumin. That indication was not there before.

What's the sonic difference? It's early yet, but so far I'd call it greater clarity and immediacy, lower-yet apparent distortion, together with larger-yet soundstaging in all dimensions and more solid imaging--the usual audiophile desiderata. This effect seems audible on all signals from low-quality internet radio streams up through high resolution programs.
 

tmallin

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I listened more late last night, after I wrote that prior post. Even at extremely low volume levels (didn't want to wake my sleeping spouse, of course!) of between 8 to 10 on the 100-point volume scale ("normal" high volume for me in this system is about 72 or so), the added clarity and transparency were amazing. It's like I suddenly had Quad 57s or some other speaker known for extreme transparency even at very low volume levels.

The Leedh volume processing can be toggled on and off at will within the Lumin App for comparison. The switchover takes less than five seconds. Thus, pretty good A/B testing of the Leedh processing is available. (This assumes, of course, that Lumin has not somehow "dumbed down" the volume control when Leedh is not engaged in the new firmware. There's no way to quickly A/B the new version of the firmware with the old version.) The difference is the proverbial "night and day." And this is even though the direct connection before seemed surprisingly sonically purer than using the special relay-controlled volume control of my Benchmark HPA4 "preamp" which I thought was pretty special indeed at the time.
 
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fish fingers

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Thanks for assessment of Leedh. Most probably purchasing either D2 or U1 mini (and Soncoz DAC), straight to Passlabs power amp
 

tmallin

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I'm cross-posting here some material I recently wrote in my Roon thread. While this applies to the Lumin X1 as fed from Roon software and the Roon Nucleus+, it may not apply to Lumin models with different processors which cannot handle native DSD 512 input:

Another sonic tweak to the sound of Roon into my Lumin X1: At least in my system, in the DSP engine of Roon, setting the DSD to PCM filter to unfiltered (instead of the Recommended 30 kHz or any other available value) results in a significant further improvement in sound quality.

I was hesitant to try this at first, given the warning in the setting and Roon documentation about it. But since I'm not converting DSD to PCM in Roon and since my Lumin X1 accepts native DSD 512, no such filtering should be necessary, right? I got brave and tried it, after trying the "permissive" 50 kHz filter and finding that to sound better than the recommended 30 kHz filter.

I'm not sure why this filter setting should be audible at all in my system since the signal path does not show any DSD to PCM conversion step within Roon or within the Lumin. But, in any event, in the specific context of my system, setting the Roon DSD to PCM filter to unfiltered sounds significantly better yet and seems safe. Nothing is overheating and there are no sonic problems or digital hiccups at all.

The combination of upsampling/resampling everything via Roon's DSP engine to DSD 512, Leedh Volume processing by the Lumin X1, and the elimination of the DSD to PCM filtration in Roon has enabled my system to push past some threshold into a realism I've never before achieved. On much program material, there is an absence of artifacts and a see-through realism which allow me to suspend disbelief to an extent never before possible. This is even true for much low-bit-rate internet radio material.
 

tmallin

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One further significant sonic tweak I just discovered for my system running Roon software on my Roon Nucleus+ feeding my Lumin X1: Turn off the MinimServer which ordinarily would serve to feed my music files to the Lumin X1 via my home network and the Lumin App. The result is significantly more solid imaging (especially in the center) combined with considerable expansion of front-to-back depth.

Why this should be so in my system is somewhat puzzling. The MinimServer program runs only on my desktop computer and accesses a copy of my music files which resides on one of the solid-state drives of that machine. Roon pulls my music files from a USB stick plugged directly into one of the USB ports on the back of my Nucleus+. The MinimServer program and its associated music files only are used if I'm directly using the Lumin App installled on my Lumin X1. The MinimServer program should not be involved at all in the playback of music via Roon.

But perhaps the connection is that the Lumin App, which is controlling the system volume and using the new Leedh DSP volume processor, and maybe the Lumin X1 itself, is relieved of processing overhead when the MinimServer program is turned off. That's the only possible explanation I can come up with. The resulting sonic improvement is not difficult to discern in my system; it is significant.
 

Empirical Audio

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I use Minimserver with Bubble UPnP as a proxy server. This improves SQ a lot. You setup proxy of Minimserver in the Bubble window.

Then in the playback app, you select the Minimserver proxy as the server. I don't use Roon for playback as I have found Kinsky to be superior.
 

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