Digital Signal Transmission

[sandyk]

6 hours ago, TomJ said:

In my opinion, there is currently so much nonsense in the forums in the field of digital singnal transmission.

 Please provide OBJECTIVE proof of your claims as required in this area of the forum, not just from yellowing old Textbooks either.

 

BTW, why do you NEED to use a USB isolator if the data is correctly received, if things such as the PSU area and EARTHING in particular in the PC/Server do not matter ? 

[sandyk]

1 hour ago, TomJ said:

 

Its so annoying - there are so many myths about digital audio, that you can not distinguish whether it is true or only justification for the price paid.

 

Then why don't you list some of the  "myths"  in order of importance that you believe are false. 

[sandyk]

24 minutes ago, pkane2001 said:

Here's one you might like: something to do with audible differences between two bit-identical files, one transferred by a USB stick, the other by a noisy internet download.

 

   You aren't the OP .😊

As he made a remark about justification for the price paid, it is more likely a question for Vendors such as Uptone, JPLAY  etc.

[sandyk]

2 hours ago, PeterSt said:

The real can of worms is about fine people like Paul, who at least is eager, where such people spread the word to you that because they can not measure "it", "it" can not be there. And there your myths are born.

 

 +1.

 Neither will they accept the results of correctly performed DBT sessions , or the indicative results of threads such as from Manishander  that deserved to be followed up on with further testing ,simply because they are unable to confirm them with their Binary comparisons or unsuitable for the purpose, choice of S/W .

 

Incidentally,  the same mechanisms can also affect high resolution Digital Video both audibly and visually.

at the same time.

https://audiophilestyle.com/forums/topic/58169-red-or-blue-pill-part-ii/?tab=comments#comment-1020293

 

[sandyk]

1 hour ago, kumakuma said:

 

A solution that only makes sense IF it is technically possible to make such modifications to the DAC AND you have the required skills and knowledge AND you have no better uses for your time.

 Even then, the front end still matters as Gary has shown here :

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

 

This needn't cost more than a few $ to obtain a very worthwhile improvement

[sandyk]

13 hours ago, TomJ said:

So I do not understand, why many so called Audiophiles prefer an unstable SPDIF and setup masterclocks for thousands of euro with the end, that transport of data is only near the quality of USB

 That statement shows a complete lack of knowledge and Anti  Subjective Bias .

Well implemented Coax SPDIF * can crap all over typical USB, even when you are using a USB Isolator.

USB is highly sensitive to the quality of the PSU area and is highly susceptible to minor earth lops and capacitance to mains earth. That is why some members use internal USB cards with a high quality low noise Linear PSU, or a USB Isolator with a separate low noise PSU . Even when using a low noise Linear PSU, simply connecting the screen of a lower noise R-Core transformer to mains earth can cause a small audible degradation. The use of a battery derived PSU, e.g. a 12 Li Ion battery using a low noise voltage regulator results in a further improvement. 

 

*By well implemented Coax SPDIF, I mean using an internal Soundcard which further improves the PSU area and results in a higher quality output than just Motherboard SPDIF, the use of isolation transformers at the PC end AND the input to the DAC, as well as the use of impedance matched plugs and sockets such as genuine 75 ohm BNC types.

 Unfortunately, these days many DACs skimp in this area due to the " Bean Counters" 

 Attached is a photo of an old modified Musical Fidelity X-DAC V3 showing how this was done properly (top of photo) This DAC also used a P.L.L. ( Phase Locked Loop) for the correct timing of the Data .

 The main drawback of Coax SPDIF is bandwidth related, which these days can easily be greatly extended using for example a wide bandwidth (200MHZ) I.C.  at the output instead of something like a typical <$1 Hex inverter I.C.

If you don't need multichannel or DSD, well implemented Coax SPDIF will easily outperform typical USB without the need for USB isolators/Regens, expensive after market USB cables and additional low noise Linear PSUs etc.

 

 See also actual USB measurements :

https://www.computeraudiophile.com/forums/topic/24275-ac-filtering-grounding-boxes-linear-psu-and-balanced-power/?page=68 posts by YashN

[sandyk]

54 minutes ago, fas42 said:

knowledge from the analogue domain can be very, very useful - just putting things into different boxes, with "Analogue", and, "Digital", labels on them doesn't solve a thing

Agreed.

The PSU area also matters just as much for the Digital area as it does for the Analogue area . and correct earthing techniques matter even more for Digital due to UHF and GHZ frequencies being involved.

Even the use of pop rivets in the construction of a PC's metal case can cause some audible degradation,  including reduced stereo separation and a degraded sound stage, as well as a grainy background or what appears to be a veil over the sound. 

[sandyk]

37 minutes ago, TomJ said:

I was talking about USB as a data transport, not as a power source for a dac,

The quality of the USB power matters just as much for DACs that don't need USB to power them.

The noisy +5V SMPS derived USB supply induces rubbish into the D+ and D- data lines of the USB cable , which is why some expensive aftermarket USB cables separately shield both power and Data .

IF you don't need your DAC to see the noisy incoming +5V you can isolate the noisy +5V at the PC end of the USB cable.

In fact, if you don't need it, as a front panel USB port is fed via a couple of  feet long internal USB cable, a further improvement can  often be obtained by cutting the red +5V wire near the Motherboard socket end of the cable.

 

 P..S.

 Even though your DAC may not be powered via USB, it may still need to see a " handshake" via the +5V from the  PC, in which case this noisy +5V can still induce RF/EMI into the Data wires 

[sandyk]

22 minutes ago, pkane2001 said:

 

Of course! Got anything objective to back up this bold and exciting claim? I'm ready to weld if you do 🤪

This came as a result from Gary's suggestion.

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

 

 Of course, if you don't believe that markedly reducing the measured A.C voltage drop between the 0 volts of the case of an internal SSD and 0 volts (Earth) of the internal PSU matters . . . . . .

 

 

https://www.google.com/search?q=replace+the+pop+rivets+in+a+PC+case&oq=replace+the+pop+rivets+in+a+PC+case&aqs=chrome..69i57.24374j0j15&sourceid=chrome&ie=UTF-8

[sandyk]

19 minutes ago, pkane2001 said:

So you’re talking about improving a ground connection, and not just about rivets sounding better? Ok, I’ll put my welder away, then ;)

 Not that your DeltaWave S/W will be likely to show the obvious audible improvements though, because your beloved checksums remained the same after the same CDs were re-ripped  !😊

OR 

 Put another way, the Binary Data remained the same.

[sandyk]

8 minutes ago, PeterSt said:

 

Alex, I think you may be confusing the handshake procedure with ground being required. Maybe in some occasions +5V is needed (I don't know about them - but that doesn't tell much 🤪) but ground most often (always ?) is required. And this ground is not required for the data ...

 No Peter .

Some DACs do need to see+5V, but all seem  to need the 0 volts reference 

[sandyk]

1 minute ago, PeterSt said:

 

Ahem. I was saying that ?

You said MAYBE in some cases. I wasn't disagreeing with you

[sandyk]

17 minutes ago, pkane2001 said:

The quality of the case rivets doesn’t matter if it’s properly grounded, Peter.

You are also ignoring the fact that the metal cases of SSD/HDD are internally connected to 0 volts. This means that if the case has a very low resistance back to the 0 volts (Earth) of the PSU via the metalwork that there will be a marked reduction in the measured rubbish voltage between the SSD/HDD case and 0 volts of the PSU with an SSD that is not securely earthed via the metalwork.  I also found a voltage drop between the top and bottom halves of my drive bay that were joined together using pop rivets. Some people apparently even go to the trouble of replacing the rivets with silver rivets !

 Remember too, that the power to some SSDs etc. may go via a couple of daisy chained 4 pin Molex connectors using cheap metal contacts that aren't always 100% reliable, and that SSDs may even generate enough RF/EMI to affect WiFi if not properly earthed and screened.

 

 

 

 

14A2-B4.pdf

[sandyk]

4 hours ago, pkane2001 said:

That's what objective evidence is, Alex.

 

 Bovine excreta  !

Just as your usual assumption that it is below the audibility threshold is  if it's over -120dB

 Your typical stance appears to be  " IF I can't measure it, then you can't hear it" 

 Yet you were unable to measure the things that Frank confirmed hearing, as another poster  from the Objective side also did, then attempted to distance himself from it. In that case it was with a couple of comparisons that sounded different despite identical Binary content, where I then removed a few mS from the beginning of one track so that they no longer had identical SHA256 checksums, yet still sounded different to both posters.

 You should find those posts somewhere in the Objective area unless the OP later edited them out to to suit his desired conclusions .

[sandyk]

2 minutes ago, TomJ said:

. They argue with UDP protocols and missing bits and this should be the reason why better "audiophile" switches improve the sound. And i am sick about these discussions.

 The obvious answer then is to ignore this forum and listen to, and view the world according to Amir and his purely measurement brigade in  A.S. where you presumably are already a devoted member ?.

[sandyk]

3 minutes ago, pkane2001 said:

Alex, civilized behavior would be much appreciated.

 Then stop bringing my name back into it, and ridiculing my reports about improving the earthing of many typical PCs as discussed by one and a half in his thread.

 

[sandyk]

1 minute ago, TomJ said:

I'm not talking about the fact that a switch cannot increase the sound quality, but that it does not change the data less than 20 $ switches.

Nobody is disputing that a switch can not increase the sound quality. 

What you refuse to accept is that the quality of the switch and it's power supply can DEGRADE the sound quality based solely on the assumption that the Data remains unchanged ,even though there may also be RF/EMI going along for the ride too, which MAY affect the resulting sound quality.

[sandyk]

15 minutes ago, pkane2001 said:

Hate to tell you, but you weren’t the Alex I was addressing.

 Your reply is every bit addressed to all participants in this thread, and once again is being used to ram down our throats content from ASR that most members are not interested in, or if they are, can choose to view their content directly.

 

Did you first seek permission from ASR Admin to repost their content in this forum ? 

 

 

[sandyk]

1 minute ago, kumakuma said:

 Yet the OP has not posted any OBJECTIVE proof of his statements whatsoever .

[sandyk]

2 hours ago, TomJ said:

However, there is still a difference here - I trust the Linux nerds to know what they are doing. Here with the audiophiles, I'm starting to doubt it. 

That has been your assertion right from your very first post. So why are you REALLY here ?

It's certainly NOT to learn from the experiences of others.

[sandyk]

1 hour ago, pkane2001 said:

You guys love to argue, but when it comes to providing any real evidence to support your arguments... crickets.

 

So, in bidding you adieu, always remember and never forget:  it’s not the fork that bends, it is only yourself ;)

 

As I suggested in another post, feel free to organise a series of correctly performed DBTs in the USA where the majority of members reside, as DBTs are supposedly the " Gold Standard" (except when the results don't coincide with E.E. and I.T. member expectations.)

 If I wasn't in Australia , I would be more than happy to demonstrate my claims using my own equipment.

In fact, when I was still living in Sydney I challenged Prof. Scott to organise with Sydney University's technical people to put my reports to the test.

 That didn't happen, so I seized the chance to contact Martin Colloms who I didn't realise was a member here until I saw a post by him, and he did put my claims to the test using comparison .wav files that I provided, with 6 separate sessions of 8 repeats in each session.

 

 Why is it so damn hard to do something similar in the USA where there are so many members ? 

 

I also recall that some years ago Chris organised a Symposium where the majority of members attending heard clear differences between SSD and HDD using the exact same Music files.

IIRC, Chris described the HDD as sounding a little muddy in comparison with the SSD .

[sandyk]

1 hour ago, TomJ said:

So I learned, that the sound can only be changed while converting from D to A inside the DAC. 

No. It can also  be changed by the PSU area of the source due both to the components used in the PSU itself, but also as Peter has explained by different software loading of the PSU area. Even the external PSU used to power Regens and switches etc. can change the sound qualities to some extent, which is why some members daisy chain ultra  low noise LT3045 voltage regulators in order to increase apparent HF detail. This is due to the output impedance of these types of  regulators being much lower at >100kHz than in the lower frequencies.

[sandyk]

11 hours ago, TomJ said:

I mean only during the conversion of D to A, or then in the analogue chain. The conversion is influenced by HF of PSU entering the DAC. But before conversion, there is no sound alive to change😀 - only data (and electrical noise/HF) and with TCP/IP and USB we get the data without manipulation into the DAC.

 Your reply is from your closed minded perspective. In  fact, the PSU area of the source, including the PSU area for the SSDs  can also affect Digital Video the same way that it affects Digital Audio, just as the same data on SSD and HDD can sound a little different, even when played directly from System Memory. I am also able to demonstrate this to those who have a decent internal video card and a good quality external monitor, as well as a better than average main system.

 I have previously had my PSU reports in this area verified with a series of 6 separate DBT sessions with results publishd in HiFi Critic Vol. 6 No.1

 It is becoming increasingly clear that you came here only to TROLL, and not learn  from the  listening experiences of members here.

Neither are you interested in any of the proof that Peter , who BTW, is the designer of one of the most highly acclaimed DACs commercially available, as well as the highly respected XXHE S/W for Windows,(http://www.phasure.com/)

went to a lot of time and trouble to provide.

[sandyk]

1 hour ago, fas42 said:

Correct. All the other circuitry can indulge in any sort of silliness that it wants to get up to, misbehave as much as it likes, electrically - you just have to stop it reaching across into the areas where the analogue waveform is directly created, or handled.

 You have a short memory span Frank, as you have personally heard and verified obvious differences generated in the front end by the PSU area .😉

 You are also neglecting that what audible differences Peter is able to cause with his S/W ,remains after conversion from D to A in the DAC as verified by Manishander in the Red Pill, Blue Pill thread..

[sandyk]

15 minutes ago, fas42 said:

 

Alex, "all the other circuitry" includes PSes, and processors running S/W - the analogue side is purely that which does the actual, direct manipulation of the waveform; this has lines coming in from power rails, input data streams, clocks, and other control circuitry and then feeding out to the next stage ... impose some unwanted noise on one of those lines, and you could have audible variations.

Frank 

What you reported on were audio files that were uploaded from the SAME folder of a USB memory stick that was plugged directly into a front USB port.

 The differences you heard were generated by using different variations of the PSU used to power the USB memory stick at the time of saving the files to the folder ,along with another version where the USB memory stick was plugged into the end of a >3M long generic USB cable at the time of saving the audio  file.

 

Alex