A Confused streaming system - Mutec / SOtM Ultra

[octaviars]

I tried the tx-USB ultra once with a PH SR3 but the power supply developed a problem. A technician fixed it and said that it cannot be completely ruled out that the problem was caused by the unit it was powering (the tx-USB ultra). So I am reluctant to connect anything else than the SPS-500 now. Hopefully, my unit will be replaced in Munich next month. Then I can do more testing.

What went wrong with the PH SR3?

I run my sMS-200ultra and tX-USBultra with two PH SR4 and they work very well. As I understand the SR4 uses the same regulator as a SR7 just less amps (2A at 5, 7, 9 or 12Vdc).

[zdenes]

I tried the tx-USB ultra once with a PH SR3 but the power supply developed a problem. A technician fixed it and said that it cannot be completely ruled out that the problem was caused by the unit it was powering (the tx-USB ultra). So I am reluctant to connect anything else than the SPS-500 now. Hopefully, my unit will be replaced in Munich next month. Then I can do more testing.

What went wrong with the PH SR3?

I run my sMS-200ultra and tX-USBultra with two PH SR4 and they work very well. As I understand the SR4 uses the same regulator as a SR7 just less amps (2A at 5, 7, 9 or 12Vdc).

Well, I was hoping that I wouldn't have to write down the story as it is long and boring   , so I will try to keep it short and simple. 

After receiving my tx-USB ultra I changed the voltage internally to work on 12V because I have the fixed voltage SR3 and JS-2 that powers the SMS-200 ultra but it has two outputs and also can be used with a Y cable, and the SPS-500. So I was hoping to do a comprehensive PS test with these three. 

As I said above, the unit didn't work reliably with the SPS-500 (strange in itself) but seemed to work a touch more reliably with the SR3. Still, it didn't fully solve the connectivity problem. 

As the problem is always finding the USB device (getting the 'USB handshake'), a friend suggested trying a USB Y cable such as Kingrex with a 5V external USB power supply. 
He lent me such a cable and it did work for a day or two, so I thought that it solved the problem, although it is still not normal behaviour from the tx-USB ultra. 

So after a few days of seemingly troubleless operation - during which time I restarted the system about 4-5 times - I thought it's time to test the SQ with different power supplies (before that, when the SR3 was in use, I was concentrating on getting the system work, not so much on SQ). 

So I reconnected the SR3 and the device couldn't connect again. Strange, I thought, as with the Y USB cable the whole thing seemed to have worked for days before that. Then got the SPS-500 back and again things work fine. At this point I had a feeling - I don't know why - that the SR3 was not outputting the right voltage. I checked it, it was only 7.5V. A few days prior to that I measured it and it was 11.8V. So three things could have happened. 

a) The external 5V on the USB cable somehow found its way back to the power supply and caused damage to parts.
b) The tx-USB ultra itself is causing trouble and resulted in the damage - unrelated to the USB external power.
c) Just a coincidence. 

In order of probability, I think it is a > b > c but even in case 'a', that should have happened if the tx-USB ultra had been working fine. 
The technician who repaired said that the SR3 doesn't have much protection for 'adverse behaviour' of the unit is is feeding or overheating or anything like that. 
 
Now, the SR-3 is fixed, some parts needed to be replaced, luckily it didn't cost much but I'm reluctant to try again. 

BTW, the connection problem surfaced again even with the 5V external power. So I removed the USB Y cable and now I just use a standard USB cable. I also changed the unit back to 9V. 
The most reliable operation seems to be at 9V and the Wireworld USB connecting the SMS-200 ultra to the tx-USB ultra, but this is neither perfect nor acceptable anyway. 

I tried two different servers, two different NAA devices, many USB and ethernet cables, installing the SOtM OS on a new microSD, reinstalling HQPlayer and even removing HQPlayer from the mix and use the SMS-200 ultra from and attached pen drive. And a few other things. Nothing worked for more than a day or two (or not at all). 

Two knowledgeable technicians (one who fixed the SR3) suggested that it could be a faulty capacitor in the tx-USB ultra some other parts that don't work reliably. 

SOtM is very good at following and guiding my quest but it seems they will have to look at the unit eventually.

[Confused]

This thread should have been so simple.  A case of someone happy with their audio system who then removes one component, replaces it with some items that are almost universally reckoned to be significantly superior, and then reports the glorious sound quality improvements that result.  What could be simpler?  The trouble is, this is not how things have worked out.  In simple terms, I have gone from a system that I have been happy with, to one that is now irritating me.  As has been reported in this thread, this has been a bit of a baffling journey, at first it seemed to be a case of the SOtM kit having a bit of HF harshness.

Interestingly, a lot of SOtM users have reported stuff along the lines of “it sounded a bit harsh when new, then things improved after 200 hours burn in, and at 400 hours it was really singing”, you know the kind of stuff.  Others had good ideas, suggesting that the SOtM’s inherent transparency was exposing shortcoming in other areas of my system, so I need to eliminate SMPS’s, get better cables, optimise the PC that feeds the sMS-200Ultra, maybe add some LPSU’s for the SOtM kit to replace the sPS-500, and so on.  Some of this might prove to be good advice, and it is standard stuff, improve transparency in one area and it exposes weaknesses elsewhere, I could sit here typing for hours giving many examples of this phenomena, but I am guessing that most people reading this will be more than familiar with this concept.

The trouble is, the more I experimented, tried different things, listened very carefully to what the system was doing, it became clear to me that none of the above was explaining what I was experiencing.  To be clear, I am not stating here that nothing written above may offer an improvement, indeed I plan to try some of the ideas written above, but the key point is that none of this explains what I have experienced when adding the SOtM kit, it just does not fit the facts. 

So why does none of this fit the facts?  As an example, take a specific section of a track that now annoys me with the SOtM kit.  Listen very carefully, A/B switch between the SOtM kit and the mR, the bit section that is annoying me is actually more clearly resolved with the SOtM kit, it sounds more realistic with the SOtM kit.  Switching between the mR and SOtM kit does require a lot of cable swapping, then software swapping (Sonicorbiter to Eunhasu), so this is not particularly rapid, but what I could do is swap between Roon AIR and the SOtM kit very rapidly, and Roon AIR is a very reasonable proxy for the mR / MC3+USB combination.  With rapid A/B switching, it was clear that aspects that were annoying me in the music were quite simply being reproduced more realistically with the SOtM kit.  So the SOtM kit was subjectively higher performance, subjectively better, but subjectively not enjoyable to listen to.  So following this logic, if improvements are making the system less enjoyable to listen to, creating some kind of psychoacoustic effect of harshness when none is there, then any other improvements, to power supplies or anything else, will simple exacerbate the issue.  Indeed, the cure seemed to be to reinstall the mR, which is lower performance and lacks the SOtM’s kit better clock performance and superior noise rejection.  Utterly baffling!

Or maybe not.  A short session with a friend on Sunday afternoon and things became clearer, and indeed many thoughts came into my head, all of a sudden memories of past experiences started to connect and I started to make full sense of what is going on.  The session last Sunday was a simple thing, I was starting to think very clearly about what was happening, and was about to try something myself, I was playing with Roon’s parametric EQ, and had simply tweaked the problematic 4.75kHz region down by 3dB.  Anyway, with this tweak in place, my friend listed to a couple of tracks.  They had no idea about the EQ, but did know I was messing about with new kit.  One track in, my friend made some positive noises about everything sounding good and then said something along the lines of “the cymbals were sensational in that that track, I don’t know how many time I have heard that track but never heard that before”.  So an overall positive response, with the performance in the HF region getting special mention.  I then mumbled something about different configurations of the new equipment, and played the same track again, this time with Roon’s EQ turned off.  My friends response?  No, not as good as the first one, the first one was much better.  OK, this was not the most extensive and scientific blind test, it was over in 15 minutes, then we both had other things to do, but it did get me thinking.

Back to the concept of improving an aspect of the system, and this makes thing sound worse.  It dawned on me that I have experienced this before, and recently too, when replacing the D800 with the 1000Pro.  Is the 1000Pro better than the D800?  Yes, definitely.  Indeed, I have had the luxury of a rapid A/B switch test between the D800 and 100Pro, thanks to the good people at Oxford Audio.  One thing I remember about this audition was how the 1000Pro had far better resolution, was far more realistic sounding, most notably in the upper mid-range area.  This test was imprinted in my memory, the 1000Pro clearly better in the higher registers.  I can also recall my last weekend with the D800, there was one track in particular that I was listening too and thinking “this sounds sensational, I can’t imagine that with the 1000Pro it will sound better than this.”  As things turned out, it didn’t.  I remember listening to this same track once I had the 1000Pro, and rather than experiencing immediate audio joy, I started to notice some issues in the HF area.  Sound familiar?  With the 1000Pro though, this made sense, I knew from the Oxford Audio audition that the Pro is better in this regard, so the Pro’s improved transparency was simply exposing some hash in the recording, or so I thought.  I was also thinking that maybe the 1000Pro deserved a better front end than the mR/Mutec, for the record the Oxford Audio audition was with the Aurender N10, a source I like a lot with the Devialet.  I have had the 1000Pro for a while now, and I have no doubt that it is superior to the D800.  That is only part of this story though, there have been times with the 100Pro when I am listening to something and miss the D800’s slightly more relaxed presentation, despite being the ‘inferior’ performer, it was somehow nicer to listen to, or perhaps more accurately characterised as nicer to listen too with some source material.  So over the last year or so, maybe I play something and there is a touch of harshness in the HF, I have put it down to the recording, or maybe start thinking that the 1000Pro deserves a better front end.  Looking back, I think this was wrong.  Certainly the 1000Pro deserves a better front end, or at least it can benefit from one, but the swapping of the D800 for the 1000Pro has created exactly the same phenomena as swapping the mR for the SOtM kit, so this was the root cause of the niggling thoughts about HF harshness.

Things are now making sense to me, I almost feel like I have discovered some new audio phenomena.  I say almost, because I am sure that many must have experienced this before me, and what I am experiencing may be well known to audio specialists or those who study psychoacoustics, I simply do no know.  Anyway, this is what I now believe is happening.  I think there is some kind of psychoacoustic effect, that when you improve the quality of reproduction, improve the resolution, it makes the frequencies observed in the presence band more apparent, it does not increase them, it just makes them more apparent when listening.  This may or may not just be in the presence or HF region, I do no know, but that is where I am experience this phenomena now.  To clarify, if I use REW and look at the in-room frequency curve, I have the normal peaks and nulls, a fairly typical bit of bass reinforcement, followed by a thankfully shallow null, normal stuff.  One key point here is that ignoring the peaks and dips, the frequency curve is pretty flat from say 200Hz to over 10kHz.  I think this is significant, because many room correction ‘house curves’ tend to have a gentle slope from bass down to the HF region.  I have never seen a house curve that increases the HF region compared to mid range.  A recall reading some material about room correction, this stated that you tend to hear frequency as hearing the peaks in the curve.  So if I do have a peak in the presence band, this will tend to be prominent in my listening.  Add the 1000Pro, this improves resolution, the presence band becomes more prominent, or perhaps more accurately the perception of the presence band becomes more prominent, then add the SOtM kit, the same thing happens and the effect becomes cumulative.  This then tips me over the edge, from something I can live with, something I enjoy, to a situation where the peaks in the presence band annoy me so much I cannot enjoy all the other good stuff that is going on.  Using this forum, I can read through old posts that I made after getting the 1000Pro, and indeed posts by others after upgrading to the Pro.  I can see I had indeed experienced this phenomena moving to the 1000Pro.  I suspect others have too when moving from Expert to Pro, there are quite a few posts about HF harshness or the Pro being less forgiving with respect to treble.  Of course, the experience of others will be system dependent.  What may be a negative in one system because of the phenomena I describe, could easily be a positive in another system where the in room presence band response is less prominent, where increased perception of the presence band would simply be perceived as greater clarity.  So that is the theory, I could write a couple more pages as to why I think the phenomena I am describing is very real, for now, please trust me, I am as convinced as I can be.  Plus, this is a theory which lends itself to a little experimentation.

So, armed with REW and Roon’s parametric EQ, I decided to tweak the EQ to remove the peaks in the presence band and thorough to the treble region.  Of course, I could try to correct bass nodes and try to mimic a house curve whilst I am at it, but for now, I want to change as little as possible, and just take out the peaks from about 2kHz upwards.  I am not an expert in room correction, in fact it is something that I have quite deliberately avoided, it somehow does not fit with my more purist approach to things.  So for today, I simply tried doing a minor room correction tweak via a method I understand, then test with REW, tweak the Roon EQ, retest and check if I have the desired curve with presence band peaks removed, then repeat until optimised.  A bit crude, but it is a method I understand and can do without spending hours messing about leaning new tricks.  Well, that was the plan anyway.  When I performed the first baseline measurement, I found that the 4.75kHz peak mentioned previously was not there, what I had now was a 5.75kHz peak.  I think I know why this is, last Sunday evening I noticed that the left hand Blade had less toe in than normal, something I had been messing about with earlier in the day.  This annoyed me, it just looked a little odd.  So I tweaked it back to where it was, or so I thought.  OK, I still have a peak, but it has moved, it just goes to show how sensitive the measurements are with respect to minor speaker changes, maybe my bogus measurements in post #131 were correct after all.  I also found that that the corrections I thought would be easy to make in Roon, were in fact not easy to make at all.  I am new to room correction, and I can now see I have much to learn, but from where I am now the changes I can make with the Roon parametric EQ are nowhere near accurate enough to do anything with my specific peaks, all I can do is get a general reduction across a couple of peaks, Roon’s EQ seams to average things out too much for what I am trying to achieve.  In fact, with a bit of playing around this morning, i can get just as nice a curve, with a bit of downward slope, by simply tuning off Roon’s EQ and tweaking the treble down on the Devialet.

I can see some potential with room correction, but I need to do a lot more reading up and learning before I can get it to do what I would like it to do.  Also, I would probably be better off investigating some improvements with room treatment first.  With the room improved there would be less for room correction to have to correct in the first place.  All this will take time, and I do not have much free time at the moment.  So, in the short term, I can best achieve what I am trying to do with a simple tweak on the treble control, crude, but no worse than I can achieve with Roon EQ at this point in time.  By chance, it would also seem that my semi-accidental speaker positioning tweak has helped.  I recall listening to the Blades at Oxford audio one time and I thought the system sounded a little dark, I visited again a week later, this time they did not sound dark at all, I think minor differences in positioning and toe-in make a big difference, maybe more with the Blades than some other speakers.

So as an experiment today, I tweaked the treble to -4dB, which should be enough to kill the presence band issue stone dead, and I sat down to listen to some familiar tracks.  Not far through the first track it became clear that the system actually sounded a little dull.  These are the margins I am talking about here.  In fact, a tweak down -1dB or -2dB seems to be all that is needed.

Realising I am going full circle to a degree here, I thought I would do a simple brain re-set and listen to some familiar demo tracks with Roon AIR, this is an effective mR+MC3+USB proxy and takes me back to where I was before the REF10 and SOtM additions.  This was actually a bit of a revelation, Roon AIR sounded dreadful!  OK, we are talking relative terms and margins here, so it was not dreadful in absolute terms, but the step back was stark.  I think I had been so focused on one aspect of the systems presentation that I had not really noticed just how big a step forward the REF10 and SOtM kit was making.

So after much messing about and much pondering, my conclusion is that the next step is to simply set the treble down by -2dB or similar, this appears to be all that is needed to kill the presence issue and prevent it bothering me with some tracks.  Then I can simply see how things go, it should end my brain's preoccupation with the prescence band issue, and I might start to fully appreciate all that goodness that the REF10 and SOtM trio are delivering.

As a final comment, if someone can explain why increasing a systems resolution can increase the apparent prominence in the prescence band, I would be most interested to learn why.

[Rama]

@Confused I have not read your post fully but just glanced through it, non the less I applaud you for its tour de force. And thanks for putting the time and effort in contributing to this forum. I myself have an SOtM 200 Ultra + sPS 500 and I plan to add the Mutec when funds permit, but I am sure in the future I will come back to this thread again and again as a source of reference.

[David A]

@Confused,

You have discovered the dark side of tweaking. All is not plain sailing.

There is a problem with trying to improve a specific aspect of sound. It can be very easy to change one thing, to get more detail for example, and find that it changes other things as well. More detail can add brightness, changing the bass or high frequency response changes the overall tonal balance and can affect how you hear the mid-range and the other end of the frequency spectrum. You find that changing one thing affects other things and improvement in one area often comes with an unwelcome cost in other things. You can then try to address those other things but that can turn into a never ending task.

To make things more complicated, it's easy to focus on the thing which annoys you. You tweak and "fix" that and you're really happy with the improvement but it can often take quite a while for you to notice the cost elsewhere. It's easy not to notice the cost while you're paying attention to the thing which initially annoyed you and enjoying the change, and it isn't until you stop paying attention to that aspect of the sound and simply start listening to the overall sound again that you notice the difference and then you can find that the end result overall isn't as much to your liking as the original sound. I once started tweaking with vibration control many years ago and got an improvement, noticed a cost, tweaked to fix the new problem, noticed a cost, tweaked again, and went through that process several times. Each time I did A/B comparisons and felt I got an improvement in the area I was interested in but then, after several successive tweaks, did an A/B comparison between my original tweak and my final result several tweaks later and removed everything but the first tweak. Focussing on individual issues blinded me to the overall sound and the end result of improving several individual "problems" one after another wasn't as good as just making the first improvement on its own.

There are reasons why people suggest that you should tweak slowly. I think burn in can be real in some cases, but I also think it takes time for us to adjust to the change in sound and become accustomed to it before we can really hear what the change actually gives us and be able to know whether or not fixing one thing is actually beneficial overall or whether the unanticipated costs outweigh the benefit of the fix. It's easy to lose sight of the forest when you're focussing on individual trees.

Over time I've learnt to become very cautious when I start making chains of changes which are intended to fix the problems that arose with a previous fix. Things become complicated and expensive and it's easy for the overall result to start going backwards without noticing it. One thing I've found which helps me is to make a change, live with it until I'm no longer noticing the change which can take a week or two, and then go back to the way things were before the change. That usually gives me a better idea of the overall benefit or otherwise of the change than several A/B comparisons at the time I introduced the change.

You asked if anyone could explain why increasing a system's resolution can increase the apparent prominence in the presence band. There could be several reasons but I strongly suspect that part of it is simply that you're noticing the presence band more because of the aspects of the sound that you're paying attention to. Paying attention to something makes us notice that thing and its immediate surroundings more than we notice other things. That's a big part of what's going on when I said above that I find that I get a better idea of the overall benefit of a change when I do an A/B comparison after I've become used to the sound and I'm no longer paying attention specifically to the change. It's a lot easier to hear whether a change improves the result musically when you're no longer paying attention to what it does to a specific aspect of the sound.

An additional thought:


You’re thinking about lowering the treble setting to deal with a too prominent presence region. That may work but it’s also possible that the solution is to leave the treble alone and to boost the bass. Those room response target curves you mentioned all start falling from the bass region. If the bottom end of the range isn’t strong enough the top end will sound bright but if you lower the top end and the bottom end isn’t strong enough in relation to the mids then you’re likely to end up with a too strong mid range which may still sound elevated in the presence region and with a top and bottom end which both end up sounding duller.

There’s that old distinction between people who see the glass as half full and those who see it as half empty. Some people have a tendency to view a rising frequency response as one with too much treble while others view it as one with too little bass. Both descriptions can often be applied to the same situation. Reducing the treble will work if the bass is strong enough in relation to the mids and presence region but you’ll get better results with increasing the bass if the bass is around the same level or lower than the mids. The response curve targets you mention all work on having the treble lower than the bass and a fairly even slope down from the bass. They don’t rely on having the treble lower than the mids or presence region, even though that will be the case if the response slopes down from the bass.

It might sound counter intuitive to fix an elevated presence/treble region by increasing the bass response rather than reducing the elevated area but depending on the bass response increasing the bass can actually be the best way to fix an elevated presence range or highs.

[sam1000]

Bravo Confused! Hope this change will bring you years of audio joy. Really applaud your efforts and documenting your experience. This was much more enjoyable read than "the veil of lifted" kind of a review :-)

One quick questions, why did you go with SMS-200Ultra when you were going to externally clock the source with Ref10?
I thought the difference between Ultra and SMs-200 was an addition of internal clock to Ultra, which you would be bypassing with Ref 10.

[Rama]

So now that I have read the whole post it seems that the issue is with harshness in HF. I had a very similar experience with my speakers and for a time I thought that the ribbon tweeters were damaged. I had the speakers returned to the factory and got the tweeters replaced. However that was not the issue. The speakers were so resolving that I was noticing every fault in the mastering. I have two solutions a) Try another set of speakers or b) Change speaker cables.

[PeppaPig]

I am not quite understand how the external clocker like MC3 can help to improve sound quality of Devialet.

When the sound is reclocked by Mc3 and then output to Devialet, the Devialet will processed it using its own internal DAC and clocker again, we cannot bypass it right?

[cereal killer]

Or simply configure a NAS to do this:

Directly connect your Devialet to a NAS via its ethernet port 2 (output) via CAT7.
Connected your NAS to a wireless router/internet via its ethernet port 1 (input) via CAT7.

NAS configuration:
Ethernet port 1: 192.168.1.100
Subnet Mask 255.255.255.0

Ethernet port 2: 192.168.2.100
Subnet Mask 255.255.255.0

Devialet configuration:
Ethernet Static: 192.168.2.101
Subnet Mask 255.255.255.0

Router/modem:
All DHCP

This configuration allows full control over roonserver installed on a QNAP or Synology NAS via roon remote on an iPad etc.
This achieves layer 3 network isolation. https://www.packetmischief.ca/2011/11/29...isolation/

[Axel]

I am not quite understand how the external clocker like MC3 can help to improve sound quality of Devialet.

When the sound is reclocked by Mc3 and then output to Devialet, the Devialet will processed it using its own internal DAC and clocker again, we cannot bypass it right?

Before the advent of the CI and Pro upgrades iirc a lot of us were unhappy with the sound quality of the USB input. AES/EBU sounded superior. Mutec came out with the MC3+USB, which as it’s name implies, has a USB input and also has an AES/EBU output. The Mutec also reclocks the incoming signal before conversion. With a decent cable, you a great digital connection.
I understand that, since the CI upgrade, USB performance has improved, although these increases are probably across the board!

The main advantage though is the ability to feed the Mutec with a 10MHz clock input, as @Confused has posted about.

All inputs go through the DAC(s).