[Mediahound]

The stock BNC cables seem quite touchy. I adjusted the cables and started experiencing drop-outs every few minutes. Prior to that I had no drop-outs at all. I have played with them a bit more and it seems reduced now, but drop-outs still happens once in a while. The drop-outs only occur in dual BNC mode.

It may be the cables. I have taken apart a pair of the supplied bnc cables. The screen crimp is only onto the soft outer insulation (as opposed to better ones where the crimp is solid onto the metal body of the connector). They are not a robust construction for long term use IMO but are fine for a get you going pair of cables. The connector itself is also built down to a price and the screen does not have much coverage. But don’t complain too much, they were free. A slightly more expensive pair of cables with canare or similar connectors may be more reliable.

Wow, hard to believe that on a US $5k product, Chord is not including quality BNC cables.

 

[dvb-projekt]

Here is my presentation from CanJam:





So here I am talking about how important timing of transients is to perception - the implication being is if transient timing has errors (transients being too early or too late, then this will degrade lateral imagery, or left to right instrument placement.


This illustrates that the brain relies on transients of bass notes in order to infer the pitch. Again, the implication is if there are timing errors then the brain will be confused and won't be able to perceive bass notes.


Again psychoacoustic studies have shown that transients are important information for the perception of timbre. Again, the implication is if transients have timing errors, then timbre perception will get degraded.


So I have talked about the fact that transients are important, and now it's about the specific timing problem that DAC's introduce.



So this is a simple illustration of the problem of reproducing transients, and why it is conventional interpolation filters create very large timing errors. So we can see here a sine wave tone burst, and the digital data actually loses the initial burst, as it samples it at the start of the transient.



So the top waveform will be the output from the "audiophile" filters - that actually create timing errors, as in this case we have a peak error of full amplitude - so the reconstruction gets the sign right, but nothing else. So in this particular circumstance, the OP is only 1 bit accurate. But the second waveform is perfectly reconstructed - and if we used an ideal sinc function filter (known as a Whittaker-Shannon interpolation filter) then it will perfectly reconstruct it, with no errors, and in particular no transient timing errors.

You may ask if the audiophile filters have such huge problems, then why do people like them? The issue is simple; when you get these huge transient errors, the brain can't make sense of the audio; when it can't make sense of something, it draws a blank, and you can't actually perceive the transients. And when you can't perceive transients properly, then things sound softer - it's the equivalent of making the image go out of focus, as you can no longer perceive sharp details. You can't follow the pitch of the bass, and it sounds big and fat. But of course the image goes big and flat too, as imagery is degraded; and instruments sound similar with poor timbre variations.



So this covers the theoretical ideal - if we use a sinc function filter, it will perfectly reconstruct it, with no transient timing errors.



But to implement an ideal sinc function interpolation filter, we need an infinite amount of processing... Something not possible!



So we can improve on conventional algorithms ability to reconstruct transients correctly - and this led to my WTA interpolation algorithm. It has been optimised to reduce the error, with a finite amount of processing (or taps). Actually, the WTA algorithm has evolved as tap length has increased, and today it is very similar to an ideal sinc function - over half the coefficients are identical to the ideal sinc function. A windowing function is the process that is used to tailor the sinc function from an infinite response into a small finite one, of a size we can actually use.



So this links history, and shows the relationship between sound quality and tap length with the WTA filter.



Some personal history - I have been waiting for this for a long time!





The importance of 1M taps is that I use identical to sinc coefficients to a 16.6 bit accuracy - this means that since it is the same as an ideal sinc function, and it's only a sinc function that will perfectly reconstruct, then we are guaranteed to reconstruct the bandwidth limited analogue signal to a better than 16 bit accuracy, with all signals, under all conditions. So your 16 bit file is now being perfectly reconstructed - at least to better than 16 bits accuracy and to 705.6 kHz (1.3 uS sample period).



I needed to create a new filter architecture in order to do the M scaler - 528 DSP's operating together, with half a million lines of code. This gives you a flavour of the complexity. Fortunately, I can verify exactly that the filter works perfectly, although it took some months to test and de-bug.



Features of the Hugo M scaler. I added the pass through mode so it was easy to be able to hear the difference.





So just to summarise. This whole concept is actually very very simple in reality:

1. We know that transients are essential from a perception POV.

2. Only an ideal sinc function interpolation filter will reconstruct the bandwidth limited analogue signal perfectly.

3. All other filters will create differences from the original analogue signal.

4. These differences will make transients come a little early or a little late, creating audible problems. The differences in timing depends upon when it was sampled, the past and future signals; so transients are randomly coming backwards or forwards; it's this constant change in the timing of transients that confuses the brain, as it can't process the audio to extract placement, timbre, pitch and tempo information all things that are essential for musicality.

5. Every time I have doubled the tap length and so increased the accuracy to an ideal sinc function by 1 bit I have noticed improved sound quality, as the transients are being more closely reproduced to the original. And the sound quality changes are consistent with what we know about transients and perception.

6. The M scaler is the same as an ideal sinc function filter to better than 16 bits; this means the bandwidth limited signal is reconstructed to a better than 16 bit accuracy.

To me, the M scaler has made a huge difference to sound quality when assessed objectively; much more importantly it has transformed my own enjoyment of music.

Rob

Dear Rob,

your decision to produce the M Scaler in a Table Top case like the "TT2" and not in a Choral case like the "Dave", does that mean that you are planning something ahead for the Choral line?

Best
Oliver

 

[Triode User]

Wow, hard to believe that on a US $5k product, Chord is not including quality BNC cables.

The Hugo MScaler is, IMO, the bargain of the decade. It is quite reasonable for Chord to have decided to include ‘get you going’ connectors rather than more expensive cables as that would have pushed up the price. Also, it is reasonable to assume that end users may wish to either have different length bnc cables or to use a make of their own choosing in which case including more expensive cables in the box would just be a waste of money.

 

[Jgeffen]

Wow, hard to believe that on a US $5k product, Chord is not including quality BNC cables.

Agree!

 

[Jgeffen]

The Hugo MScaler is, IMO, the bargain of the decade. It is quite reasonable for Chord to have decided to include ‘get you going’ connectors rather than more expensive cables as that would have pushed up the price. Also, it is reasonable to assume that end users may wish to either have different length bnc cables or to use a make of their own choosing in which case including more expensive cables in the box would just be a waste of money.

In my opinion it's a typical niche product and certainly not 'the bargain of the decade'.
But okay, there are similar DAC products with a much higher price.
And then, in comparison, you could say it's a bargain.

 

[Triode User]

In my opinion it's a typical niche product and certainly not 'the bargain of the decade'.
But okay, there are similar DAC products with a much higher price.
And then, in comparison, you could say it's a bargain.

The only other comparable product is the Chord Blu Mk2 MScaler at approx twice the price. So yes, bargain of the decade is the what I would call it (and I did say IMO). A bargain does not mean something is cheap.

 

[Jgeffen]

The only other comparable product is the Chord Blu Mk2 MScaler at approx twice the price. So yes, bargain of the decade is the what I would call it (and I did say IMO). A bargain does not mean something is cheap.

Your are right, but for me the M Scaler is it just a part of a Chord DAC setup, so in price you could compare this setup to an other high end DAC, and choose between the two. If the Chord setup is much better than others soudwise and much lower in price, then it is a bargain IMO. But for me this isn't clear yet, although I'm dreaming of a M scaler in my setup, but 4 grant, is still a lot of money IMO.

 

[Rhamnetin]

Wow, hard to believe that on a US $5k product, Chord is not including quality BNC cables.

Good to know. I may just order some affordable Tara Labs cables with it then.

 

[AndrewOld]

Yep, my cables do not like being touched while in use, even gently.

These look like decent cables:

https://www.ebay.co.uk/itm/Digital-...anare-true-75ohm-BNC-High-specs-/400076881452

or these

http://www.bluejeanscable.co.uk/store/digital-audio/index.htm

so I think I shall go for one of them, or something similar. £50 or so a pair is reasonable. It may well be the case though that the connection inside the cable is fine, it’s the touching of the BNC connectors that upsets the data flow for some reason so a fancier cable might dislike being touched just as much.

 

[marcmccalmont]

Yep, my cables do not like being touched while in use, even gently.

These look like decent cables:

https://www.ebay.co.uk/itm/Digital-...anare-true-75ohm-BNC-High-specs-/400076881452

or these

http://www.bluejeanscable.co.uk/store/digital-audio/index.htm

so I think I shall go for one of them, or something similar. £50 or so a pair is reasonable. It may well be the case though that the connection inside the cable is fine, it’s the touching of the BNC connectors that upsets the data flow for some reason so a fancier cable might dislike being touched just as much.

These seem to be better shielded
https://www.ebay.com/itm/BNC-Quad-S...5b1847b4:m:mxpYchP1JrhgYSAqjoV5vrQ:rk:26:pf:0

 

[Jgeffen]

Yep, my cables do not like being touched while in use, even gently.

These look like decent cables:

https://www.ebay.co.uk/itm/Digital-...anare-true-75ohm-BNC-High-specs-/400076881452

or these

http://www.bluejeanscable.co.uk/store/digital-audio/index.htm

so I think I shall go for one of them, or something similar. £50 or so a pair is reasonable. It may well be the case though that the connection inside the cable is fine, it’s the touching of the BNC connectors that upsets the data flow for some reason so a fancier cable might dislike being touched just as much.

Atlas is quite good too, I love their cables; high price-quality.

https://www.futureshop.co.uk/atlas-element-bnc-75-ohm-sp-dif-digital-audio-cable

 

[AndrewOld]

These seem to be better shielded
https://www.ebay.com/itm/BNC-Quad-S...5b1847b4:m:mxpYchP1JrhgYSAqjoV5vrQ:rk:26:pf:0

Could be, but they don’t ship to U.K./Europe which is where I happen to be.

 

[AndrewOld]

Atlas is quite good too, I love their cables; high price-quality.

https://www.futureshop.co.uk/atlas-element-bnc-75-ohm-sp-dif-digital-audio-cable

I’m sure that’s fine too. It’s not rocket science. But remember, if you spend more than £50 on cables an angel dies, so shhhhh.

Anybody got any bright ideas for neatly stacking/arranging their M Scaler and DAVE and laptop or other source?

 

[SCBob]

I’m sure that’s fine too. It’s not rocket science. But remember, if you spend more than £50 on cables an angel dies, so shhhhh.

Anybody got any bright ideas for neatly stacking/arranging their M Scaler and DAVE and laptop or other source?

I don't have the Chord ensemble stand for DAVE but wonder if the stand can be set up to slide the M Scaler under the DAVE?

 

[AndrewOld]

I don't have the Chord ensemble stand for DAVE but wonder if the stand can be set up to slide the M Scaler under the DAVE?

I’m sure it might be, but I couldn’t possibly bring myself to spend that kind of money on a support, far too many fairies would die. I’m looking for something simple, elegant, well designed, and sensibly priced.