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1 minute ago, fas42 said:

Definitely had times over the years when it was clear that the dry heat situation made the SQ more on the edge - so I certainly agree that humidity control can help matters.

 An Evaporative Cooler can assist there.

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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6 hours ago, Abtr said:

Any thoughts about how static charge may audibly affect sound quality?

Ask Frank !  😉

Personally, I doubt that it is a problem other than when it occurs .IOW, momentary .

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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53 minutes ago, sandyk said:

Ask Frank !  😉

Personally, I doubt that it is a problem other than when it occurs .IOW, momentary .

 

Static has always been a problem - first good rig 3 decades ago had it bad; but at that time I had no awareness of such things - so I spent a huge amount of time and effort trying to get a handle on the situation; which failed, because I was not looking at the right things. Meant I gave up taking audio seriously for years, the frustration of not getting an answer burnt me out for quite some time.

 

"Momentary" is the last adjective I would use 🙂 ... what static does is kill the 'liveness' of the sound; the low level detail which is so important is masked, blurred and hifi moves towards midfi. If one gets a system which is completely free of static, there is a 'rightness' to the sound which is so satisfying, addictive - it might take exposure to a rig which is fully free of such issues, and then add static; and go back and forth between the two a few times to fully appreciate what happens. This is exactly what happened to me over 30 years ago - and it drove me nuts! At the time, the only solution I had was to power down, leave it for a bit - and then switch on again ... and then the static would slowly start building up, in another round of the cycle ...

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13 minutes ago, sandyk said:

Ask Frank !  😉

Personally, I doubt that it is a problem other than when it occurs .IOW, momentary .

Yes, a static charge may be a problem when it is abruptly discharged (if that's what you mean), even when it is discharged to ground. That's what causes a USB disconnect in my system. But imagine a static charge that continuously builds up and continuously leaks current into a DAC or a DDC. Could that affect SQ? I think so. In my setup, touching USB GND causes an instantaneous static discharge which disconnects USB, whereas grounding USB GND through a 100K Ohm resistor prevents the static buildup and improves SQ. Just grounding USB GND without the series resistor audibly reduces SQ, probably because of a ground loop.

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4 hours ago, Abtr said:

, whereas grounding USB GND through a 100K Ohm resistor prevents the static buildup and improves SQ. Just grounding USB GND without the series resistor audibly reduces SQ, probably because of a ground loop.

Which is basically what I have been saying elsewhere, where I suggested earthing SMPs devices via a 100 ohms resistor which is too high in resistance to result in an audible earth loop.

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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11 hours ago, sandyk said:

Which is basically what I have been saying elsewhere, where I suggested earthing SMPs devices via a 100 ohms resistor which is too high in resistance to result in an audible earth loop.

Thanks for the PM. The only difference in my system is that USB GND is earthed through a 100K Ohm series resistor (not 100 Ohm) for optimal SQ..

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3 hours ago, March Audio said:

Contrary to popular audiophile belief, ground (as in a connection to the physical earth and mains electrical safety earth) is not a sink for noise. Noise does not go into it and disappear.

Exactly!

Power line noise wants to get back to its source not to Planet Earth. And its source is that big power company transformer down the street.

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On 1/12/2021 at 10:07 AM, sandyk said:

Which is basically what I have been saying elsewhere, where I suggested earthing SMPs devices via a 100 ohms resistor which is too high in resistance to result in an audible earth loop.

Well sort of :)

 

Think about it a different way.  What happens when a current flows through a resistance?  A voltage is developed across that resistance.  Higher the resistance, higher the voltage.

 

So in the case of a single ended RCA system such as a dac and amp the two components are connected together often with interconnect shield connected to mains earth in one or more places.  This creates the infamous ground loop.

 

a27d24_62f5390b4394488e951afc640a3d3b28~mv2.webp

 

If you have high resistances in the interconnect shield you will often generate higher voltages and therefore more likely to have noise issues.  Select interconnect cables with thick low impedance shields, not for shielding but to minimise the noise voltage generated across them.  Same goes for USB cables.

 

With SMPS remember that they have Y capacitors connecting live to earth to reduce EMI.  You are injecting noise straight into the earth conductor and this is most likely at some point connected to your interconnect shield and signal low.

 

So really the upshot of this is that single ended RCA connections are just a really bad idea and earth connections in such a system only ever cause problems.

 

All issues simply avoided with balanced connections where the noise currents dont flow in the signal low, they flow harmlessly in the separate shield wire and dont corrupt your valuable musical signal.

 

a27d24_7a031814ea324053af85d338c06bd808~mv2.webp

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7 hours ago, March Audio said:

So really the upshot of this is that single ended RCA connections are just a really bad idea and earth connections in such a system only ever cause problems.

I completely disagree, and my set up is nothing like you have described.

The earth reference of the whole system come from the Power amplifier 10 ohm earth lift resistors all the way back to the DAC All are directly (DC) coupled, and with only the "earth"/0 volts of the selected input switched through.

The Preamp is powered by the secondary windings of 2 separate 18-0-18 toroidal transformers in a 2 U Rack case that also has dual regulated PSUs for the 15WClass A PA. The noise from the Preamp is only a slightly thicker centre trace on a CRO at maximum sensitivity,  when preceded by a 10 x low noise battery powered PSU and Preamp at max. gain of 3.2

The case of the Preamp is connected to the case of the PA, but is not earthed internally, even via the transformer secondary windings. Only the case of the DAC is earthed.

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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Some good points but a few things to clarify.

 

Firstly im afraid osilliscopes are no good for measuring noise, especially digital ones which, unless you have an extremely expensive one, will only have only be 8bit.  The highest sensitivity might be 5mV/div when you require more like 1uV.

 

If there is a smps in the system  dac, pc etc you will have alost certainly have leakage currents that end up in your interconnect shield.

 

Also I think the point is that whatever you have done in your system doesn't mean that the basic principles I described in the above posts are not happening in many other systems.  It is a fundamental flaw if RCA connections where the low signal conductor is used as a shield and to connect different components chassis and 0v together. Currents will flow in that shield and modulate your audio signal.

 

It doesn't mean that everyone is suffering from audible hums and noise.

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Just going back to the point about scopes, 8 bit is a SNR of 42dB.  You want to be looking to maybe 120dB down.  You can get higher resolution scopes but look at the price tag 😀

 

https://www.keysight.com/au/en/product/MSOS104A/high-definition-oscilloscope-1-ghz-4-analog-16-digital-channels.html#DynamicTable

https://www.ebay.com/c/20008923922

 

Also scopes are very high bandwidth, typically 100MHz upwards so have a lot of wideband noise obscuring the lower frequency audio band noise that you want to see.

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36 minutes ago, March Audio said:

Some good points but a few things to clarify.

 

Firstly im afraid osilliscopes are no good for measuring noise, especially digital ones which, unless you have an extremely expensive one, will only have only be 8bit.  The highest sensitivity might be 5mV/div when you require more like 1uV.

 

If there is a smps in the system  dac, pc etc you will have alost certainly have leakage currents that end up in your interconnect shield.

 

Also I think the point is that whatever you have done in your system doesn't mean that the basic principles I described in the above posts are not happening in many other systems.  It is a fundamental flaw if RCA connections where the low signal conductor is used as a shield and to connect different components chassis and 0v together. Currents will flow in that shield and modulate your audio signal.

 

It doesn't mean that everyone is suffering from audible hums and noise.

 The noise I was measuring here was with the Selected Input terminated with a 1Kohm resistor at maximum preamp gain.

It was an old DSE C.R.O.

 There was the slightest hint of some SMPS from a nearby 40" "LED" HDTV on standby,  

There were no other SMPS devices in use at the time, and as I mentioned, the shields of only the selected input  are switched through the Preamp. Yes, the shortest possible high quality  double screened leads were used (Belden 1855A BLUE 75 Ohm RG59/U )

 Why do people keep neglecting the additional electronics needed for balanced circuitry, perhaos with more base/emitter junctions in the path, and the need to have very accurate matching between halves , and IDEALLY an improved PSU for best results

 Neither are there also benefits of a dB or 2 perhaps S/N in all applications, as Elias Gwinn from Benchmark discusses in the attached .
 BTW, the noise does not necessarily need to be audible with your ears right next to the speakers to subtly affect the overall SQ .

 

 

Elias Gwinn- Benchmark.txt

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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10 minutes ago, March Audio said:

Do not use mains filters with Y capacitors installed. An Y capacitor makes a capacitive connection (several nf) from the mains lines to your chassis and hence audio ground.

YES, and even the capacitance between Primary and secondary windings of a transformer matters 

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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19 minutes ago, sandyk said:

 The noise I was measuring here was with the Selected Input terminated with a 1Kohm resistor at maximum preamp gain.

It was an old DSE C.R.O.

 There was the slightest hint of some SMPS from a nearby 40" "LED" HDTV on standby,  

There were no other SMPS devices in use at the time, and as I mentioned, the shields of only the selected input  are switched through the Preamp. Yes, the shortest possible high quality  double screened leads were used (Belden 1855A BLUE 75 Ohm RG59/U )

 Why do people keep neglecting the additional electronics needed for balanced circuitry, perhaos with more base/emitter junctions in the path, and the need to have very accurate matching between halves , and IDEALLY an improved PSU for best results

 Neither are there also benefits of a dB or 2 perhaps S/N in all applications, as Elias Gwinn from Benchmark discusses in the attached .
 BTW, the noise does not necessarily need to be audible with your ears right next to the speakers to subtly affect the overall SQ .

 

 

Elias Gwinn- Benchmark.txt 2.19 kB · 0 downloads

Analogue CRO are not much better than digital.  It wont even have 16bit (96dB) SNR.

 

People dont neglect the issues of balanced circuitry.  There can be poor balanced implementations just as there can be bad single ended implementations.

 

Modern balanced implementations are neither complex or expensive.  They can perform as well single ended and avoid the inherent issues it has.

 

Dont forget that probably every single recording you have was recorded on balanced equipment.

 

Anyway thats not what we are actually discussing here, its not balanced V single ended, its the issues of ground connections.

 

BTW balanced headphone amps is a different issue. This isnt the same as a balanced interconnection between components. The only advantage they have is that they dont share a common gnd between the left and right driver and avoid crosstalk as a consequence.  However if your headphones have seperate gnd conductor that only joins at the plug/socket on the amp then its a pretty much non issue anyway.  the issue of crosstalk only gets worse by a few dB.  Balanced headphone drive has no other advantage.  Actualy there are a few points in the clip you posted that are not strictly correct, but thats another discussion for elsewhere.

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7 minutes ago, March Audio said:

Dont forget that probably every single recording you have was recorded on balanced equipment.

 So ?

 That does not mean that you need to use balanced playback to hear the recordings at their best. That's governed mainly by the quality of the PSU and DA conversion even in the PC where the main problem area is RF/EMI due to digital processing in the front end . 

From another Aussie :

https://audiophilestyle.com/forums/topic/60381-hdd-to-case-bonding-uptick-in-sq/?tab=comments#comment-1102477

 

Yes, if you don't have the components adjacent, and need to have leads more than several metres long,

Balanced is obviously the way to go.

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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It simply means that in a professional environment no-one has any issue with balanced equipment or its performance.

 

If you take a look on another forum you will see that all the best performing components are actually balanced.

 

Well implemented balanced sounds no better or worse than single ended. The issues I have described above are not dependant upon distance between components, although long cables will generally make the situation worse.  The issue is a fundamental limitation of single ended conections and a fundamental advantage of balanced.

 

PCs are chock full of high frequency currents and of course have large SMPS.  You dont really want a shielded connection going from that to a dac without some kind of galvanic isolation. Many dacs have this over their USB connection however I have seen quite a few threads elsewhere where people have suffered from  "computer noises" coming out their systems.  This is those currents getting into the shield wired on the interconnnects and flowing to the next component.

 

I note that the OP in your link was using ethernet to his dac.  Ethernet has isolation transformers so there is no direct connection.  So long as you dont use shielded Ethernet cable which could join the chassis together then there is no issue.

 

I think this is going off topic

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17 minutes ago, March Audio said:

It simply means that in a professional environment no-one has any issue with balanced equipment or its performance.

 It also means that in a typical home environment in the suburbs, not a USA mansion etc. and don't own a dedicated listening room, that most people are unable to appreciate the extra couple of dB S/N at around -130dB or whatever. Even then there are still numerous members who use Hollow State electronics or Vinyl who will rarely benefit further. 

 

Seen  many balanced ultra Low noise RIAA Phono Preamps recently ?😜

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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1 hour ago, sandyk said:

 It also means that in a typical home environment in the suburbs, not a USA mansion etc. and don't own a dedicated listening room, that most people are unable to appreciate the extra couple of dB S/N at around -130dB or whatever. Even then there are still numerous members who use Hollow State electronics or Vinyl who will rarely benefit further. 

 

Seen  many balanced ultra Low noise RIAA Phono Preamps recently ?😜

This isnt the case.  As I mentioned people with very ordinary set-ups do get hums and they certainly do suffer from "computer noises" which is the more modern manifestation of this fundamental problem.  It can certainly be more than a few dB.  If you are at the level of bonding the components inside a PC to improve sound quality, as you pointed out in a previous post, then you really are concerned about "a couple of extra dB".

 

In terms of audibility of course there is a debate to be had about at what level things become an overt problem, but lets face it there are lots of people around here that will say they can hear things that arent even remotely measurable ;)

 

Anyway thats not really relevant to what we are discussing here - the issues of ground connections.

 

Phono pres are often hissy and pick up mains hum.  Balanced would have another benefit of common mode rejection which would help minimise that hum.  Mic pres are balanced for this reason.  I used to work in instrumentation and you always used balanced (differential) input amps for looking at similar low level audio frequency signals from things like strain guages. This minimises noise pick up.

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3 hours ago, March Audio said:

As I mentioned people with very ordinary set-ups do get hums

I have been involved in numerous listening sessions with quite a few Audiophile friends, with quite a few met via DIY Audio, yet I have never heard any noticeable hum issues ever. Perhaps these people knew how to avoid such problems ? 

 I have however heard on several occasions, obvious degradation due to USB limitations, especially when using Laptops and Servers.

 

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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