[nomad777]

I hope that the improvement you have described is still audible, especially as it was achieved at no cost !. Interesting though, that what you heard regarding sharper vocals, the snare hits sharp and defined would probably be described as RFI artefacts by the maker of the cables you have bought. Anything described as bright or sharp is seemingly frowned on. Darker, smoother sound is the aim.

Not really to dark is not good either. That can mean hardware design compromises. When I bought the Innuos server and listened to music initially I didn't like it. Way to dark. At least for me. So I did things to compensate and improved the sound. At that time I was also testing the Antipodes DSGT via a home demo and the sound signature was so much better than the Innuos. This is one of their older versions. Smooth, buttery almost. With better detail. I wouldn't call it brighter but more detail combined with smoothness. I made the choice then to move over to Antipodes. I later found out how they achieve their sound signature and have talked to the Owner/President which solidified my switch. Long blurb to say dark isn't always better.

 

[Lgn3]

Not really to dark is not good either. That can mean hardware design compromises. When I bought the Innuos server and listened to music initially I didn't like it. Way to dark. At least for me. So I did things to compensate and improved the sound. At that time I was also testing the Antipodes DSGT via a home demo and the sound signature was so much better than the Innuos. This is one of their older versions. Smooth, buttery almost. With better detail. I wouldn't call it brighter but more detail combined with smoothness. I made the choice then to move over to Antipodes. I later found out how they achieve their sound signature and have talked to the Owner/President which solidified my switch. Long blurb to say dark isn't always better.

As it happens I agree about too dark. Like no doubt other contributors to this forum I try to listen to live music of different genres as often as possible. Whether it be classical, jazz or folk I never come away thinking the sound in the auditorium was really dark compared to listening to my home system.

 

[Progisus]

Dark for me is when the music sounds as if it comes from the vacuum of space. It can startle me at times. When I get this effect while using the Utopia I know my system is performing at it’s best.

 

[dmance]

I trust (hope) that we're all aware that any changes on the digital side don't change the bitstream. You can tweak all you want: servers, cables, power, etc ...and the bits arrive at your DAC exactly the same.
So when the sound changes its due to the dreaded word which may not be spoken on this forum.
So, in my view, there is an objective 'best' sound from a DAC ..and that's when it is as devoid of that dreaded word. None on the signal, none on the power feed and minimized thru free air.
It is then that, yes, there is an uncanny realism from a deep, dark void of incredible width and depth. This is your DAC laid bare: reference voltage ruler flat; ground plane absolute zero; bits-to-volts conversion exactly as the designer intended.

 

[Lgn3]

I trust (hope) that we're all aware that any changes on the digital side don't change the bitstream. You can tweak all you want: servers, cables, power, etc ...and the bits arrive at your DAC exactly the same.
So when the sound changes its due to the dreaded word which may not be spoken on this forum.
So, in my view, there is an objective 'best' sound from a DAC ..and that's when it is as devoid of that dreaded word. None on the signal, none on the power feed and minimized thru free air.
It is then that, yes, there is an uncanny realism from a deep, dark void of incredible width and depth. This is your DAC laid bare: reference voltage ruler flat; ground plane absolute zero; bits-to-volts conversion exactly as the designer intended.

So if, for the sake of argument, one accepts what you say, is that not rather depressing ? As probably 99% of home installations will not be devoid of RFI, in the terms you have described, it means that just about every DAC made and listened to is/has been compromised. Furthermore what does it say about the designers and manufacturers of DACs ? Have they tested their products free from RFI, knowing that in nearly every case the purchaser will not be using them in a free from RFI environment ? Or have they also never heard what their products are truly capable of ? Then again are there some designs that have inbuilt protection from RFI ? It would be interesting to hear some thoughts from the design side.

 

[Uncle Monty]

I wonder if DAC designers build something in to compensate for assumed RFI?

 

[ZappaMan]

The RF problem is real but it is becoming a bit boring now. Let's move on together as one in total unity.

But wasn’t the blu 2 thread also like this? I’m not sure. Seems like the best way to keep everyone happy is to have another thread for people who want

So if, for the sake of argument, one accepts what you say, is that not rather depressing ? As probably 99% of home installations will not be devoid of RFI, in the terms you have described, it means that just about every DAC made and listened to is/has been compromised. Furthermore what does it say about the designers and manufacturers of DACs ? Have they tested their products free from RFI, knowing that in nearly every case the purchaser will not be using them in a free from RFI environment ? Or have they also never heard what their products are truly capable of ? Then again are there some designs that have inbuilt protection from RFI ? It would be interesting to hear some thoughts from the design side.

why would @ray-dude say that his sotm sounds like an improvement in the context of using opto? If he already addressed rfi, why do digital upstream components improve his sq i wonder.

 

[miketlse]

Deleted

 

[gnomen]

yes i think Mike has put his finger on it - developers design, test and manufacture their devices in 'clean' environments. We have not reached the point where they need to be tested in 'hostile' envirnoments like, say, a 4-wheel drive.

I am curious how adding the Opto-DX for example to an already clean signal can make a further difference. We are still talking about the digital domain. Does it mean that any IM contamination on the incoming signal gets converted so it is included in the optical signal?

 

[Triode User]

I think that the point is that the signal is unlikely to be clean. Otherwise RF filtering would not make any difference to the sound.

As regards a contaminated signal getting encoded into the optical signal, no I know of no way for that to happen.

However, when the signal is back in the electrical domain the rf can renter the system and get into the DACs analogue stages. It is pernicious.

 

[miketlse]

Deleted

 

[Lgn3]

yes i think Mike has put his finger on it - developers design, test and manufacture their devices in 'clean' environments. We have not reached the point where they need to be tested in 'hostile' envirnoments like, say, a 4-wheel drive.

I am curious how adding the Opto-DX for example to an already clean signal can make a further difference. We are still talking about the digital domain. Does it mean that any IM contamination on the incoming signal gets converted so it is included in the optical signal?

I would suggest that developers need to test their devices in the environments in which they are to be used. You would not want to board a plane that had not been tested in the air.

 

[Lgn3]

It may seem depressing until one steps back, and pauses for breath, to understand in more depth the mathematical information theory, and the physical implementation constraints that face all dac designers.

Firstly all dacs are based on Shannons information theory - and one consequence of it is that a data signal (eg PCM) can be perfectly converted back to audio, if you use an infinite number of taps, and an infinite number of data samples. Based on those criteria alone, every dac ever made (or can be made in future) represents a compromise, because they use only a small fraction of infinite taps and data samples. This includes even Robs dacs, because even 1 million taps and hundreds of data samples in parallel, represents far less than infinity. Having said that, his dacs are the least compromised dacs currently available to the general public. Rob has posted many times that the next big question for him, is whether 1 million taps and hundreds of data samples in parallel, represents the limit of data conversion, beyond which the human brain can detect no further musical improvement. That question can only be tested/answered by him developing/testing the 2M scaler.
All dac designers and manufacturers are well aware that their products represent a compromise, compared to the mathematical perfection possible with infinite taps and data samples.

Secondly you need to consider how Shannons mathematical theory is physically implemented in practice.
Robs research over the decades is demonstrating that minute levels of noise in the dac ground plane, have negative impacts on the ability of the human brain to process sound, to accurately distinguish the stop/start of music transients.
This noise can have multiple root causes, including the oft mentioned RFI, or electrical noise transferred along cables from power supplies, music sources, etc. Overall this means that even if dac designers and manufacturers could develop a no-compromise dac with infinite taps and data samples, all their efforts can then be compromised by a physical design that allows the ingress of any minute amount of RFI or electrical noise.
All users of dacs now live in modern environments awash with RFI or electrical noise, unless they live in the middle of a huge desert, with no neighbours, no public power supply, no phone signal, no AM/FM radio signals, no electrical routers, fridges, a/c units, etc. Anyone who claims otherwise is deluding themselves. All owners need to appreciate that operating their hifi, dacs, etc without any compromise in the modern world is impossible, unless one forgoes phones, radio, power supplies, electrical equipment, etc.

This is a good point to reflect on the context of @dmance posts, because no matter how much effort Rob or other dac designers put into filtering out RFI and electrical noise, their gear is going to be used in 'hostile' environments. @dmance is merely pointing out that owners do have various options to make their music listening environments, as 'minimally hostile' as possible, in order to allow their dacs to deliver the best level of music reproduction that is possible in such an environment.

Thanks for the reply. I know about Shannon's Information Theory so I do not need to step back too far to pause for breath !

No, seriously, I know about it in this sense:

http://www.science4all.org/article/shannons-information-theory/

but not in this sense:

https://en.wikipedia.org/wiki/Information_theory

As an arts graduate I feel particularly challenged by:

I hope that you take the above in the light hearted way it is meant.

Seriously, though, if a ferrited cable can supposedly make such a difference to SQ when used with HMS to a Chord DAC I wonder why Chord do not make and include one with HMS. With economies of scale it would probably add no more than £100 to the cost.

 

[AndrewOld]

This image shows the difference between pure and contaminated signals.


The top of the image shows a perfectly clean signal passing through a cable as a series of 1s and 0s.

The bottom half of the image, shows the same signal, but with the addition of ripple added to the 5V and 0V levels, either because of RFI or electrical noise present in the source equipment, or picked up by the unshielded cable. The 0V ripple is received at the dac end of the cable, and passed into the ground plane.
Using a pure optical cable removes the electrical connection, so that the ripple cannot reach the dac.
Opto-DX extends this by taking the coaxial cable at the source end, and using a transmitter circuit to convert the 'noisy' analogue signal to a clean optical signal, which is fed into the optical cable.
At the receiver end, there is a similar receiver circuit, converting the optical signal back to the analogue signal expected by the dac.
In addition it is recommended to power the transmitter and receiver circuits, using a battery pack or other ultra low noise power supply, to avoid accidently reintroducing ripple noise into the analogue signal.

So the top level principles behind Opto-DX are straightforward.
Hope this helps.

Were these measurements made on the cables connecting an M Scaler and a Chord DAC? Or are they just hypothetical?

 

[AndrewOld]

It may seem depressing until one steps back, and pauses for breath, to understand in more depth the mathematical information theory, and the physical implementation constraints that face all dac designers.

Firstly all dacs are based on Shannons information theory - and one consequence of it is that a data signal (eg PCM) can be perfectly converted back to audio, if you use an infinite number of taps, and an infinite number of data samples. Based on those criteria alone, every dac ever made (or can be made in future) represents a compromise, because they use only a small fraction of infinite taps and data samples. This includes even Robs dacs, because even 1 million taps and hundreds of data samples in parallel, represents far less than infinity. Having said that, his dacs are the least compromised dacs currently available to the general public. Rob has posted many times that the next big question for him, is whether 1 million taps and hundreds of data samples in parallel, represents the limit of data conversion, beyond which the human brain can detect no further musical improvement. That question can only be tested/answered by him developing/testing the 2M scaler.
All dac designers and manufacturers are well aware that their products represent a compromise, compared to the mathematical perfection possible with infinite taps and data samples.

Secondly you need to consider how Shannons mathematical theory is physically implemented in practice.
Robs research over the decades is demonstrating that minute levels of noise in the dac ground plane, have negative impacts on the ability of the human brain to process sound, to accurately distinguish the stop/start of music transients.
This noise can have multiple root causes, including the oft mentioned RFI, or electrical noise transferred along cables from power supplies, music sources, etc. Overall this means that even if dac designers and manufacturers could develop a no-compromise dac with infinite taps and data samples, all their efforts can then be compromised by a physical design that allows the ingress of any minute amount of RFI or electrical noise.
All users of dacs now live in modern environments awash with RFI or electrical noise, unless they live in the middle of a huge desert, with no neighbours, no public power supply, no phone signal, no AM/FM radio signals, no electrical routers, fridges, a/c units, etc. Anyone who claims otherwise is deluding themselves. All owners need to appreciate that operating their hifi, dacs, etc without any compromise in the modern world is impossible, unless one forgoes phones, radio, power supplies, electrical equipment, etc.

This is a good point to reflect on the context of @dmance posts, because no matter how much effort Rob or other dac designers put into filtering out RFI and electrical noise, their gear is going to be used in 'hostile' environments. @dmance is merely pointing out that owners do have various options to make their music listening environments, as 'minimally hostile' as possible, in order to allow their dacs to deliver the best level of music reproduction that is possible in such an environment.

If “Robs research over the decades is demonstrating that minute levels of noise in the dac ground plane, have negative impacts on the ability of the human brain to process sound, to accurately distinguish the stop/start of music transients.” why did he allow those levels of noise to get through to the ground plane? Is he incompetent? Why can no one produce measurements to show the effects of the preposterously expensive cables they are hyping?