Bits is bits?

[sandyk]

3 minutes ago, Ralf11 said:

the fact that the most anti-audiophile poster on here believes that simply using a green pen around the circumference of a CD results in higher SQ, speaks volumes about the fragility of these minds

 

Some people prefer the sound of a little added Jitter.

Actual measurements later  revealed that there were indeed differences, but this was due to increased Jitter.

 Unlike you, at least they could hear the very real differences !

[Ralf11]

1 minute ago, sandyk said:

 

Some people prefer the sound of a little added Jitter.

Actual measurements later  revealed that there were indeed differences, but this was due to increased Jitter.

 Unlike you, at least they could hear the very real differences !

 

 

please cite to the DBT's showing that differences were detectable (now that you have changed your position on it being of higher SQ)

 

Oh wait!!  I forgot - you don't "believe" in science.

 

 

NeverMiind

[jabbr]

5 hours ago, sandyk said:

 

 In the vast majority of cases,  audiophile products use transports made by a small number of other manufacturers.

 

Right, so I am saying that rather than spend $10,000 or whatever on a cable that is really Belden under the hood, just use Belden. 

 

Or like the DACs that use a $50 USB interface and charge $10K for the DAC that itself has an ESS chip, there’s a lot of nonsense. 

 

So y’know ya da ya da ya da if someone is selling better SI I want to see the data not just blah blah blah.

 

ill say this for @PeterSt‘s NOS1a, that he uses a unique USB interface and his own USB isolation — this is what I expect.

[mansr]

On 9/1/2019 at 9:39 AM, Confused said:

So, are the manufactures making this stuff up to promote their widgets?  Or is it a case that that at the margins, improving the eye pattern beyond the specification defined limits where correct recovery of the data can occur, will actually produce an audible or measurable difference to sound quality?

This is the receiver sensitivity eye as specified by the USB 2.0 standard:

 

As long as the signal stays out of the central hexagon, the data will be received without error. If the cable length is increased, the attenuation also increases, causing the high and low levels of the signal to creep closer to the forbidden area. The transmitter and cable requirements are formulated such that the signal remains valid for all permitted configurations.

 

When noise and jitter are considered, things get a little more complicated. Although the received signal on average follows a nice path around the eye opening, random noise and jitter cause some blurring as can be seen in the scope images Superdad posted in the referenced thread. With a given average signal shape and noise/jitter distribution, it is possible to calculate the probability that the actual signal will cross into the keep-out area during a single unit interval. This probability is typically small but non-zero. With a longer cable, the signal is closer to the limit to begin with, meaning that the error rate caused by a given noise level to increases.

 

As John Swenson recently detailed elsewhere, actual error rates were vanishingly small (as in no error occurred during his testing) using various random cables up to 2 m in length. Under such conditions, when the signal is already good enough for perfect recovery, a decrapifier isn't going to make any difference. The only time such a widget will help is if it has better sensitivity than the final receiver, and the signal quality falls somewhere in between the two levels. Such a situation can arise in a few different ways:

• The DAC fails to meet specified requirements. Don't buy that DAC.
• The source fails to meet specified requirements. Don't buy that source.
• The cable fails to meet specified requirements. Don't buy that cable.
• A very long cable is an absolute necessity.

In the last of these scenarios, use of a decrapifier may be justified. For that reason, I'd like to see a simple test performed:

1. Connect a typical source to a USB-S/PDIF converter using a 5 m generic cable.
2. Play a test signal while capturing the output for a few hours. Count the errors.
3. Insert decrapifier and repeat the play/capture. Count the errors.
4. Compare the number of errors in steps 2 and 3.

Has anyone done such a test? What were the results?

[jabbr]

4 hours ago, mansr said:

In the last of these scenarios, use of a decrapifier may be justified. For that reason, I'd like to see a simple test performed:

1. Connect a typical source to a USB-S/PDIF converter using a 5 m generic cable.
2. Play a test signal while capturing the output for a few hours. Count the errors.
3. Insert decrapifier and repeat the play/capture. Count the errors.
4. Compare the number of errors in steps 2 and 3.

Has anyone done such a test? What were the results?

 

Nice post and I generally agree. There is a set of situations where the signal hits the eye-pattern but might affect SQ.

 

1) I think perhaps the biggest benefit from one of the devices is to replace a really crappy USB power with a clean 5V supply. I’ve heard hiss & cracked removed and suspect it’s the supply.

 

2) Cables and devices might taper rise time. Too fast a rise time can induce ringing in the receiver — other duty cycle modifications could presumably affect the DACs USB receiver.

 

One could test the ubiquitous  $50 Amanero to see presumably. The specific test that I would do is to send a 50% DSD signal in ie 1/0/1/0 and then do an eye-pattern on the Amanero DSD line(s) ie after conversion from USB ... if noise doesn’t make it to this point, really hard to see how it could affect the DAC.

 

Obviously this will all be DAC dependent.

[marce]

38 minutes ago, jabbr said:

 

2) Cables and devices might taper rise time. Too fast a rise time can induce ringing in the receiver — other duty cycle modifications could presumably affect the DACs USB receiver.

 

 

 

 This would be noticeable on the eye diagram.

[mansr]

2 hours ago, jabbr said:

1) I think perhaps the biggest benefit from one of the devices is to replace a really crappy USB power with a clean 5V supply. I’ve heard hiss & cracked removed and suspect it’s the supply.

A really poor power supply can of course affect overall performance of a device. However, most serious DACs are self-powered. Moreover, there are requirements regarding bus power quality from a USB host. A bus powered device should be designed to tolerate the worst permissible case without significant degradation.

 

2 hours ago, jabbr said:

2) Cables and devices might taper rise time. Too fast a rise time can induce ringing in the receiver — other duty cycle modifications could presumably affect the DACs USB receiver.

USB 2.0 specifies a minimum rise/fall time of 500 ps.

[jabbr]

5 hours ago, marce said:

 This would be noticeable on the eye diagram.

 

Yes but the eye-diagram rise time lower limit might cause ringing in a $50 USB interface. Not enough to lose bits, but enough, perhaps to affect SQ. Again I’d like to see the I2S/DSD eye-diagram to see if there are effects. If not then end of story.

[jabbr]

3 hours ago, mansr said:

A really poor power supply can of course affect overall performance of a device. However, most serious DACs are self-powered. Moreover, there are requirements regarding bus power quality from a USB host. A bus powered device should be designed to tolerate the worst permissible case without significant degradation.

 

The Pro-next S2D is an outstanding and affordable bus powered DAC that I have found sensitive to power supply in certain situations. My personal experience. 

 

3 hours ago, mansr said:

USB 2.0 specifies a minimum rise/fall time of 500 ps.

 

I’ve seen the minimum rise time specified at 300 ps with a max roughly 1 ns according to the eye diagram (which itself places no lower limit on rise time).

 

Obviously we expect the interface to have a low BER, but again, if there is no effect of variations in rise time (within spec) on the interface’s I2S/DSD eye plot itself then this is a nonissue.

[sandyk]

6 hours ago, jabbr said:

1) I think perhaps the biggest benefit from one of the devices is to replace a really crappy USB power with a clean 5V supply. I’ve heard hiss & cracked removed and suspect it’s the supply.

 

 You don't necessarily need to use one of those devices, although it makes the job easier.

I constructed the attached for use with an STB after the  change from mpeg2 to mpeg4 at too low a bit rate for a local HDTV station resulted in an image very little better than SD . Later they increased the bitrate and it was no longer needed. 

It also does what you have mentioned here with performance close to that of an Uptone USB Regen with a cleaner supply.

[Ralf11]

Pro-ject S2, right?

 

Pro-next got phoned in

[fas42]

19 hours ago, Ralf11 said:

the fact that the most anti-audiophile poster on here believes that simply using a green pen around the circumference of a CD results in higher SQ, speaks volumes about the fragility of these minds

 

Interesting how people can't comprehend that doing something "dumb" can alter the electrical environment, and behaviour of circuitry, sufficiently to cause audible changes - which then informs one that there is at least one critical area of the system which is highly sensitive to variability of the environment ... the point is, not to keep doing "dumb things", but to isolate where the fragility in the linked chain is - and fix it properly ...

 

Having just done an extended bit of driving, the attitude of some here reminds me of people who suffer a broken drive belt, and who will just sit there and steadfastly refuse to accept anything except an appropriately certified mechanic coming along, after a couple of days perhaps, to insert the correct replacement part - whereas another person will cobble together something perhaps with a stocking or other bits, and limp to the nearest garage, to then be able to continue their journey far, far sooner.

 

[kumakuma]

14 minutes ago, fas42 said:

 

Interesting how people can't comprehend

 

 

Even more interesting how someone can turn one idea into 5280 posts.

[fas42]

11 minutes ago, kumakuma said:

 

Even more interesting how someone can turn one idea into 5280 posts.

 

Also interesting is that people believe that the 'magic' of brilliant technical measurements of some part of chain can somehow compensate for subtle, non-obvious flaws elsewhere ...

 

If one idea allows one to consistently achieve excellent value for effort and money results, as compared to the general lacklustre standards exhibited by efforts which have lots of technical resources and money thrown at them - then there is a very, very faint chance that there may be some tiny smidgen of value in that idea ...

[kumakuma]

22 minutes ago, fas42 said:

 

Also interesting is that people believe that the 'magic' of brilliant technical measurements of some part of chain can somehow compensate for subtle, non-obvious flaws elsewhere ...

 

If one idea allows one to consistently achieve excellent value for effort and money results, as compared to the general lacklustre standards exhibited by efforts which have lots of technical resources and money thrown at them - then there is a very, very faint chance that there may be some tiny smidgen of value in that idea ...

 

More spam that has nothing to do with the post quoted. 

[sandyk]

1 hour ago, kumakuma said:

 

Even more interesting how someone can turn one idea into 5280 posts.

 

 Or another one with 4446 posts, and another  at the last count with 11837 posts , keep ridiculing all subjective reports in the same sarcastic manner, while rarely posting anything positive and informative in the threads concerned .

[kumakuma]

3 minutes ago, sandyk said:

 

 Or another one with 4446 posts, and another  at the last count with 11837 posts , keep ridiculing all subjective reports in the same sarcastic manner.

 

Frank's content-free posts don't even rise to the level of subjective reports. 

[fas42]

26 minutes ago, kumakuma said:

 

More spam that has nothing to do with the post quoted. 

 

Oh, it's very much on topic ... from the article that we're supposedly discussing:

 

Quote

 

Summary

Anyone with a well-set-up, transparent system will find that nearly everything makes a difference. It’s just a matter of deciding if that difference is worth their time and money.

 

 

Spot on. I'm one of the people who have discovered that expending time, in my instance, is very vital - because the difference is, literally, everything. Of course, if one wants to hide in the illusion that because a few measurements come up squeaky clean, that all is in order, well ... .

 

[kumakuma]

16 minutes ago, fas42 said:

 

Oh, it's very much on topic ... from the article that we're supposedly discussing:

 

 

Spot on. I'm one of the people who have discovered that expending time, in my instance, is very vital - because the difference is, literally, everything. Of course, if one wants to hide in the illusion that because a few measurements come up squeaky clean, that all is in order, well ... .

 

 

The sentence immediately following the one you quoted makes it clear that the author of the article has an outlook on life 180 degrees removed from yours.

[jabbr]

1 hour ago, Ralf11 said:

Pro-ject S2, right?

 

Pro-next got phoned in

Thankfully our brains (like digital systems) have good pattern matching error correction  

[sandyk]

20 hours ago, jabbr said:

Right, so I am saying that rather than spend $10,000 or whatever on a cable that is really Belden under the hood, just use Belden. 

 

 I don't have a problem with that reply. I use Belden cables wherever possible, and in most cases they do sound better than generic cables.  For example, I use Belden 1855A BLUE 75 Ohm RG59/U Type Coax Cable in my DIY Interconnect leads.

[jabbr]

7 minutes ago, sandyk said:

 

 I don't have a problem with that reply. I use Belden cables wherever possible, and in most cases they do sound better than generic cables.  For example, I use Belden 1855A BLUE 75 Ohm RG59/U Type Coax Cable in my DIY Interconnect leads.

 

Belden is s great company but I don’t have any knowledge that their analog cables are special — OTOH their copper Ethernet twists are bonded so constant impedance, and the REVConnect is special.

[fas42]

17 minutes ago, kumakuma said:

 

The sentence immediately following the one you quoted makes it clear that the author of the article has an outlook on life 180 degrees removed from yours.

 

Because he's using a 'method' that works for him; or for his business, . Again, if the integrity of the full system is not up to scratch, then all these "fiddly things" will make a difference, perhaps enough to satisfy the listener. I prefer to attack the problem at the core of what's causing the SQ to be degraded, in the important subjective areas - the most effective route to a solution.

 

In the end, we just want the music to sound good ... if someone is happy with the results using an approach that has me scratching my head about it, I'm not going to suggest that he should undo it, just because it's not my way, .

[sandyk]

8 minutes ago, jabbr said:

 

Belden is s great company but I don’t have any knowledge that their analog cables are special — OTOH their copper Ethernet twists are bonded so constant impedance, and the REVConnect is special.

One of the advantages of the cables I mentioned is that even the stranded shield is copper, and solderable.

 An E.E. friend likes them too.

Quote

This means our BNC cable is ready to meet today's requirements for 3 Gbps signal / data serial interface.

• The Belden 1855A Sub Miniature Video Coax 23 AWG 1 is a precision broadcast video cable for analog and digital signals. It can be used for narrow-band composite through wide-band SDI transmissions. Stranding is solid and the conductor is bare copper. Insulation material is gas-injected foam high density polyethylene and the outer shield is of two layers, with layer 1 made of aluminum foil-polyester tape-aluminum foil and featuring 100% coverage and layer 2 made of tinned copper with 95% coverage. Max pull tension is at 36 lbs and bend radius at 1.5". Impedance is 75 Ohm and overall diameter .159".

 

[Ralf11]

59 minutes ago, sandyk said:

 

 Or another one with 4446 posts, and another  at the last count with 11837 posts , keep ridiculing all subjective reports in the same sarcastic manner, while rarely posting anything positive and informative in the threads concerned .

 

This site needs more Magical Thinking!

 An E.E. friend says so too.