Hugo M Scaler by Chord Electronics - The Official Thread
Dec 20, 2019 at 11:42 AM Post #9,781 of 18,292
A. My guess is that optical at 24b would be best sounding. Try both, and see for yourself; use a test track that has good depth (I use an organ track), and the one that has the best perception of depth plus the warmest tone, is the more accurate/transparent one.

B. No - it's not dithered down to 24 bits but very aggressively 11th order noise shaped. Now noise shaping at 768k with my truncation noise shaper (the truncation noise shaper actually has a different architecture to pulse array noise shapers), allows for -301 dB accuracy (so a -301 dB signal is accurate to +/-0.001dB in amplitude and +/- 0.001 deg in phase) and better than 350dB THD and noise within the audio bandwidth. This is measurably perfect small signal performance, and it's something that, based on my listening tests, is essential for transparent sound quality (that is maintaining depth perception).

When the M scaler was first put together with the Blu 2, I spent a lot of time in listening tests to get the maximum SQ performance (and here the problem is trying to add a digital module without it reducing my perception of sound stage depth), and this is how I came up with the 11th order truncation noise shaping. Now this is something one can do at 768k; but at 44.1 or 48k you cannot do this, so when converting to n bits down to 24 bits than you have to use dither. As part of my ADC project, I wanted dither to sound as good as the noise shaping - so started with rectangular and triangular dither (TPDF). Rectangular sounded the worst, but TPDF was still much inferior to the 768k noise shaping; I then used pseudo Gaussian dither, and this got me much closer to the noise shaper performance compared to TPDF - but it was still no where near as good as the noise shaped performance. Incidentally, if you have a truncation setting for a filter, never switch dither to off, the small signal distortion then becomes huge. If you have the option use Gaussian dither - if this isn't available (it's very rare) then triangular or TPDF.

As far as the Davina project goes, I still have more work to do, in order to improve 44.1k truncation to 24 bits. Perhaps making the pseudo Gaussian more Gaussian may help close the SQ gap.

C. Any change in the digital data requires re-quantization if there is a truncated data residual (the bits that can't be transmitted). And my answer B shows this can only be done at 705/768 when using advanced noise shaping. So even using a -0.001dB change would create problems in depth perception; this is why my standard advice is to keep it source bit perfect - and that ignores the fact that any up-sampling filter is not the same as a WTA filter.
This is further under the hood than I've ever been. Got me looking again into DSP texts, noise shaping, various probability distribution function dithers and other goodies. No pretense at fully understanding, just taking a crack at some of this with MatLab to see darkly through DSP looking glass. Loving it. BTW, just a listener with no connection to any audio device manufacturers save with credit card.

Listening to Joel Ross KingMaker as I write this. Stunning. Best recording of vibraphones (and an excellent ensemble, particularly the drummer) I've ever heard due to musicianship/recording quality and wonderful Qobuz (96/24 signal)->HMS->Wave Storm->Dave->Utopia signal transducing system.

Thank you for sharing and Happy Holidays!
 
Last edited:
Dec 20, 2019 at 1:25 PM Post #9,782 of 18,292
I know this is going off topic, but had to reply. I still have 200 cassettes and a “hi-fi” cassette player, and out of curiosity I dug it all out, plugged in some modern easy to drive headphones. OMGoodness, they are never going to see the light of day again!
Well the days of chromium dioxide or metal tape cassettes are long ago history for me.

But I have to I admit that I am sometimes quite amazed at how realistic some of the well recorded analogue recordings of the 60s and 70 can sound played either on rbcd or as hi res downloads via my HMS.
 
Last edited:
Dec 20, 2019 at 4:48 PM Post #9,785 of 18,292
Thanks for the link. Do you use the Qobuz PC app or listen to Qobuz via Roon. I can't find a way to defeat the volume control on the app. Max volume appears to be 2 or 3 db higher compared to a CD played on the Blu 2. Have you noticed this? It is hard to know if the CD and Qobuz streams are the same though. I just go by the release date. I want to get a bit perfect output from Qobuz. Thanks Neil

i listen to Qobuz via Roon but with that album I have a ripped version on my Innuos Zenith SE also played through Roon. Volume is set as Fixed in device output in Roon.
 
Last edited:
Dec 20, 2019 at 10:06 PM Post #9,786 of 18,292
i remember making my own playlists recording radio songs to cassette in the late 80's. i had to time it so as to miss adverts and DJ commentary...:smirk:
 
Dec 21, 2019 at 4:56 PM Post #9,787 of 18,292
i remember making my own playlists recording radio songs to cassette in the late 80's. i had to time it so as to miss adverts and DJ commentary...:smirk:

I think everyone that lived through that era made their own mix tapes.

Sunday radio charts was one of my faves for making tapes, but you had to be fast enough to push pause when the DJ started cutting in when the song was nearly finished.

Then along came twin cassette deck Boom Boxes and stereo's, ripping mix tapes went to another level, the master of that level was Radio Raheem.

RIP Radio Raheem

 
Dec 23, 2019 at 7:53 AM Post #9,788 of 18,292
Solo piano by Paul Bley 'Open, to love'. one of the most influential solo piano recordings in jazz history. Really nice with mscaler. Very calming and relaxing.

R-494926-1391943804-3821.jpeg.jpg
 
Last edited:
Dec 24, 2019 at 12:22 AM Post #9,789 of 18,292
You can find the depth test on Youtube here:


Thanks for the recommendation, it's spectacular! Funny how well-suited the Pictures at an Exhibition is to the organ—never occurred to me.

Listening to this on Qobuz with MScaler->DAVE->Utopia. I think the second track shook a filling loose :)

cheers,
muski
 
Dec 25, 2019 at 4:15 PM Post #9,791 of 18,292
Thanks for the recommendation, it's spectacular! Funny how well-suited the Pictures at an Exhibition is to the organ—never occurred to me.

Listening to this on Qobuz with MScaler->DAVE->Utopia. I think the second track shook a filling loose :)

cheers,
muski

So I guess E.L.P. was not in your horizon as a band? I used to really like their records and of course they did Pictures.
 
Dec 26, 2019 at 9:58 AM Post #9,792 of 18,292
First - happy holidays all!

I've been using the holiday to further refine my front end, because I just can't keep well enough alone. A few posts back I had spoken a buying a new streamer / server - but decided to hold back - mainly because no matter what I try, I get the best result from Toslink. (I am currently running MScaler > DAVE with WAVE BNC Cables.)

It's really strange about Toslink. Everyone hates it except those who have Chord (and potentially PS Audio) DACs - because they have good jitter rejection. I assume most modern Dacs have good jitter rejection (I have no idea if it's as good as chord, although consistently toslink sounds the best for me now).

With the added resolution from M Scaler, I feel that it's even more important to mitigate RFI interference. Toslink does that best. I'd like to hear USB outputs from an Auralic Aries G2, a Lumin U1, or a Innuous Zenith MkIII to see if they've minimized EMI/RFI so that it's not discernible. I know Innuous says the Toslink receiver generates more noise - but the USB receiver is still a more complex protocol so that has to generate noise as well, no?

Anyhow - what I've decided to do before making a huge investment is a server is to get the absolute best Toslink output I possible can - and see if I can discern any difference.

I have an Auralic Aries Femto and Auralic Aries Mini. I had been using the Mini's toslink, because my particular Femto can't get to 192khz over toslink. The Mini toslink sounds great. But it can't do DOP. This isn't a huge deal in and of itself. I convert DSD to PCM in Roon, and away we go.

But what bothered me is why it can't do DOP. Did Auralic block DOP on the mini, or is it something else. It's something else. The Auralic Aries Mini doesn't send out bit perfect data via SPDIF. I confirmed this by encapsulating a dsd album in PCM with DB Poweramp and attempting to play it back in Roon. This, admittedly, pissed me off. I have all processing off in Lightning DS (the Aries control app), and no DSP in Roon. Yes, it's not the end of the world to not output bit perfect data. But I want to control that - and I want to be able to know if my music is going to my DAC bit perfect or not. I believe this is the case with Aries streamers that have a built in DAC (altair, altair g1) - because it's applying some type of filter to the digital outputs before it gets to the DAC (likely the same filter it applies to it's internal DAC, as it's on at the same time). There is no issue running DOP with the Auralic Aries Femto (via Coax at least, because the optical can't get to 192)

So this led to a rabid search for a Toslink that can run bit perfect at 192khz. In terms of USB to SPDIF converters I currently have a Gustard U12 lying around and a BelCanto Reflink. The Bel Canto Reflink is older, but doesn't have toslink out. It has ST Fiber out, AES, and BNC. BNC works to 192, does DOP - and sounds good - but not as good as Toslink. It also seems like the gain is significantly reduced vs my other sources. Not sure why this is. Interestingly, the Lifatec website has a cable with an ST Fiber connector on one end, and toslink on the other. They say that ST Fiber and Toslink were never intended to work together - but sometime they do! I also read that some people have take an ST Fiber cable and stuck it in a toslink input - and it worked! I ordered a cheap ST fiber cable just to test if M Scaler can lock onto anything. If it does, maybe I'll buy that Lifatec cable.

So last night I listened to Aries Femto USB > Gustard U12 Optical > M Scaler. It had the same warmth / tone of Toslink, but sounded ever so slightly different. One of my favorite albums is Morph the Cat by Donald Fagen - which I know backwards and forwards. I noticed two main differences - mainly in regards to detail. First, I noticed some horn trills that I hadn't previously noticed. I can't imagine missing them before. Secondly, the vocals seems clearer, but not sharper. All of these were quite small differences so could be placebo - or could be because I was sending a bit perfect signal via toslink for the first time!

Next I listened to Beethoven Around the World: Vienna - Op.59 Nos. 1&2. It's a great recording. When listening this time through this chain, it actually sounded worse in some ways. The cellos at the beginning, previously, really had a 3 dimensional characteristic which was flattened somewhat. The violins sounded "wetter" - which is the best way to describe it - because they sounded drier previously.

I have noticed this wetter sound I've typically associated with more RFI, but I don't know how it could be getting in. From a mains standpoint, I moved power supplies for the Aries and Gustard to a different circuit anyway, as they are completely isolated from the M Scaler > Dac > Amp - since their only connection is Toslink.

I don't frequent Audio Science Review frequently, but the Gustard is supposed to be a bit jittery via coax, so I can only imagine toslink is a bit worse. Could it be that there is less jitter on my aries mini, and this overshadows it's outputting a signal that's not bit perfect?

So I've decided to up my toslink game to see if jitter can play any role. I just ordered a Matrix X SPDIF 2. This seems to be the current USB to SPDIF hotness. Raved about on CA, even ASR says it measures great. Most importantly @ray-dude uses it and likes it. If I run Aries Femto USB > X SPDIF 2 - will this give me a great toslink output? Supposed to receive tomorrow so I'll find out.

I know that Chord Dacs are supposed to be 99% immune to jitter - but maybe that 1% is making a difference - or maybe I am just a crazy audiophile. Nonetheless, I'd like to get an output that sounds as good as my Aries Mini toslink, that is bit perfect - so I think it's a worthwhile exercise.
 
Last edited:
Dec 26, 2019 at 10:26 AM Post #9,794 of 18,292
So I've decided to up my toslink game to see if jitter can play any role. I just ordered a Matrix X SPDIF 2. This seems to be the current USB to SPDIF hotness. Raved about on CA, even ASR says it measures great. Most importantly @ray-dude uses it and likes it. If I run Aries Femto USB > X SPDIF 2 - will this give me a great toslink output? Supposed to receive tomorrow so I'll find out.

I know that Chord Dacs are supposed to be 99% immune to jitter - but maybe that 1% is making a difference - or maybe I am just a crazy audiophile. Nonetheless, I'd like to get an output that sounds as good as my Aries Mini toslink, that is bit perfect - so I think it's a worthwhile exercise.

I've been eyeing the X spdif2 for a while now myself but have been holding back due to some holiday expenses, hopefully I'll get my hands on one early next year. Would be nice to hear your impressions on it once you get yours :)
 
Dec 26, 2019 at 10:29 AM Post #9,795 of 18,292
@Drewligarchy
Drew,
Chord DACs are 100% immune to jitter.
What you are not considering in your analysis is how the DAVE is acting as an antenna and picks up all the radiated RF noise you are surrounding it with. All those gadgets may seem innocent placed neatly on your audio rack but they send up a flood of radiated digital RF that shows up on the output of the DAVE (or Hugo2, TT2, etc.). Its easy to measure (i do this every day) and then readily establish the corollary that the magical transparency you crave varies as you alter the level of impinging RF.
Try this convincing experiment: get the longest Toslink cable you can find that still works for you - 15' or 20' perhaps. Then exclude the MScaler from your chain (for this test) and physically separate your source chain of components from your DAVE by the max distance and do your best to isolate the power paths. Toslink eliminates the conducted RF path to your DAVE and the greater distance diminishes the radiated RF effect. You will notice that the benefits/changes of your tweaks are greatly lessened ...in fact, if it was possible to have a 100' Toslink cable and the room for separation, you would find that your source chain does not matter at all.
Dan
 
Last edited:

Users who are viewing this thread

Back
Top