USB Cable Upgrade?

[AnotherJoe]

Dacs that run in adaptive and adaptive asynchronous mode both use isochronous transfer. The adaptive part is about reclocking the input (or assigning to the output) to reduce jitter.

Asynchronous dacs on the other hand can use bulk transfer. However I am not aware of any DAC that uses retry. The nature of realtime streaming means it is not appropriate. The problem here is that other data on the same bus can take priority over the bulk transfer, and affect latency. This means that the potential retry of lost data is not possible - so you still rely on CRC and trying to conceal errors (if there are any).

 

[cheeseboy]

Just passing something on that I was told recently...

A manufacturer (not of the cables) was playing about with USB cables for use with their USB based product/products, and found that the Chord USB cable, when used with a printer, had a slightly larger file size showing after the transfer in comparison to a bog standard cable. I've not seen proof of this, but the rep had no reason to tell me this, other than his surprise at the outcome.

Make of that what you will

:rofl:

nothing to do with the cable. Size on disk and size of files differ. Try right clicking on a file in windows and go to properties. there will be 2 file sizes. The size on disk depends on the cluster size of the format of the media. A smaller cluster size will lead to a more accurate file size, but usually slower disk access, whereas a larger cluster size will lead to a less accurate size, but usually faster disk access.

 

[chebby]

Just passing something on that I was told recently...

A manufacturer (not of the cables) was playing about with USB cables for use with their USB based product/products, and found that the Chord USB cable, when used with a printer, had a slightly larger file size showing after the transfer in comparison to a bog standard cable. I've not seen proof of this, but the rep had no reason to tell me this, other than his surprise at the outcome.

Make of that what you will

I'll bet manufacturers love telling reps this sort of thing. The reps tell the dealers, the dealers tell the customers.

I wonder if they place bets on how long it takes before it pops up on a hi-fi forum somewhere as a new 'fact'.

Dave, with the access you have to 'Audiophile' cables, i'm suprised you haven't tried to replicate this phenomena on your own printer with a simple cable swap.

It should also, in principle, work with downloading RAW images via two different USB cables connecting an SD card reader. (If it's true.)

 

[BenLaw]

Just passing something on that I was told recently...

A manufacturer (not of the cables) was playing about with USB cables for use with their USB based product/products, and found that the Chord USB cable, when used with a printer, had a slightly larger file size showing after the transfer in comparison to a bog standard cable. I've not seen proof of this, but the rep had no reason to tell me this, other than his surprise at the outcome.

Make of that what you will

I'll bet manufacturers love telling reps this sort of thing. The reps tell the dealers, the dealers tell the customers.

I wonder if they place bets on how long it takes before it pops up on a hi-fi forum somewhere as a new 'fact'.

Dave, with the access you have to 'Audiophile' cables, i'm suprised you haven't tried to replicate this phenomena on your own printer with a simple cable switch.

Even taking this nonsense at face value, a 'slightly larger file size' would mean what, my songs last two seconds longer?! Was the printed page slightly blacker?

 

[John Duncan]

Just passing something on that I was told recently...

A manufacturer (not of the cables) was playing about with USB cables for use with their USB based product/products, and found that the Chord USB cable, when used with a printer, had a slightly larger file size showing after the transfer in comparison to a bog standard cable. I've not seen proof of this, but the rep had no reason to tell me this, other than his surprise at the outcome.

Make of that what you will

The experiment was inherently flawed. He took two scans and one was a different size from another, which could have happened by a slight movement in the paper being scanned (or any number of other variables). If he had taken one file and transferred it using two different cables and ended up with two different sized files, I would be 1) very surprised and 2) very afraid for my data.

 

[RobinKidderminster]

+1 but Im off to do some scanning ...

 

[Andrew Everard]

Just passing something on that I was told recently...

A manufacturer (not of the cables) was playing about with USB cables for use with their USB based product/products, and found that the Chord USB cable, when used with a printer, had a slightly larger file size showing after the transfer in comparison to a bog standard cable. I've not seen proof of this, but the rep had no reason to tell me this, other than his surprise at the outcome.

Make of that what you will

The experiment was inherently flawed. He took two scans and one was a different size from another, which could have happened by a slight movement in the paper being scanned (or any number of other variables). If he had taken one file and transferred it using two different cables and ended up with two different sized files, I would be 1) very surprised and 2) very afraid for my data.

The fact that the story has changed from it being a writer who did the 'experiment' rather than a manufacturer, and it being a scanner not a printer, shows how easy it is for the 'Send three and fourpence, we're going to a dance' effect to come into play.

 

[chebby]

+1 but Im off to do some scanning ...

I'd like to, but I don't have the Chord USB cable (or any 'hi-fi' USB cables come to that).

Do you have the Chord USB or are you just going to compare two standard cables?

 

[RobinKidderminster]

Yup total poppycock Id say. Sorry! Three scans of a document taken straight after one another. NO changes to anything. The size of the images (immediately saved) are all different.

QED Id say.

 

[relocated]

Just checked one I have Lindy 2.0 High Speed USB so guess should be fine!

Just to get back to your question while others are clawing each others eyes out.

The above cable will be fine, you need spend no more.

Think about it logically. When you print out a picture of a person on an inkjet, using a usb cable, does that picture miss off someone's ears or change the colour of their shirt or dress if you don't use an expensive usb cable? No, of course not.

Keep your money in your pocket, keep to 5m or less cables and stop worrying. :O

 

[relocated]

Just passing something on that I was told recently...

A manufacturer (not of the cables) was playing about with USB cables for use with their USB based product/products, and found that the Chord USB cable, when used with a printer, had a slightly larger file size showing after the transfer in comparison to a bog standard cable. I've not seen proof of this, but the rep had no reason to tell me this, other than his surprise at the outcome.

Make of that what you will

The experiment was inherently flawed. He took two scans and one was a different size from another, which could have happened by a slight movement in the paper being scanned (or any number of other variables). If he had taken one file and transferred it using two different cables and ended up with two different sized files, I would be 1) very surprised and 2) very afraid for my data.

The fact that the story has changed from it being a writer who did the 'experiment' rather than a manufacturer, and it being a scanner not a printer, shows how easy it is for the 'Send three and fourpence, we're going to a dance' effect to come into play.

:O "Three and fourpence", can't you get arrested by the EU Metric Police for saying that?

 

[chebby]

"Three and fourpence", can't you get arrested by the EU Metric Police for saying that?

Unlikely, because they are probably just as apocryphal (outside the pages of the Daily Mail*).

*Real life.

 

[John Duncan]

Just to get back to your question while others are clawing each others eyes out.

No clawing going on here, since everybody seems to agree...

 

[cheeseboy]

Just to get back to your question while others are clawing each others eyes out.

No clawing going on here, since everybody seems to agree...

is that allowed? Doesn't the world implode if that happens?

 

[RobinKidderminster]

I am certainly not involved with clawing - I really try to avoid 'arguments' and find it distasteful. I think we mostly try exmine the evidence, either fact or opinion, to enlighten our own judgements. I think in this case it would seem that the filesize issue can easily be tested and hence we can eliminate the cable from making a difference. The wider issue of USB cables making any difference is covered here already. What surprised me was that a length of only 5m is very significant. I would therefore suggest that 3m or 2m or maybe 1m COULD have SOME effect so maybe we should choose a good solid cable for our digital needs. £5, £10, £50, £200 ??? Therein lies our choice and benefits remain as elusive as ever.

Cheers to all - a gorgeous morning down here. Off to lunch in the garden

 

[John Duncan]

I think in this case it would seem that the filesize issue can easily be tested and hence we can eliminate the cable from making a difference.

Not quite correct. You have shown that file size can vary with nothing changing, but that does not mean that file size would *not* change if the cable changes.

Maximum cable lengths (and reasons for) are specified in the various USB standards:

http://en.wikipedia.org/wiki/Universal_Serial_Bus#Cabling

 

[RobinKidderminster]

I think in this case it would seem that the filesize issue can easily be tested and hence we can eliminate the cable from making a difference.

Not quite correct. You have shown that file size can vary with nothing changing, but that does not mean that file size would *not* change if the cable changes.

Maximum cable lengths (and reasons for) are specified in the various USB standards:

http://en.wikipedia.org/wiki/Universal_Serial_Bus#Cabling

Mmmm Am I being picky? Sorry if I am but surely if we change cables then the filesize WILL change because if we dont change cables it will anyway?? I guess I am saying that simply seeing a change in filesize in this way can not be attributed to a cable and any test of this kind will not yield any conclusive results.

Lunch! ...

cheers

 

[John Duncan]

Mmmm Am I being picky? Sorry if I am but surely if we change cables then the filesize WILL change because if we dont change cables it will anyway?? I guess I am saying that simply seeing a change in filesize in this way can not be attributed to a cable and any test of this kind will not yield any conclusive results.

Correct, this filesize change canot be attributed to the cable because the cable did not change. But that does not disprove that a cable change can not change file size. I'm fairly sure we can take it as read though

 

[quadpatch]

What surprised me was that a length of only 5m is very significant. I would therefore suggest that 3m or 2m or maybe 1m COULD have SOME effect.

Or if this bugs you get the Audioquest Dragonfly and have no cable at all . Do you think they made that DAC to make their own cables useless or to prove a point?

 

[BenLaw]

I think in this case it would seem that the filesize issue can easily be tested and hence we can eliminate the cable from making a difference.

Not quite correct. You have shown that file size can vary with nothing changing, but that does not mean that file size would *not* change if the cable changes.

Maximum cable lengths (and reasons for) are specified in the various USB standards:

http://en.wikipedia.org/wiki/Universal_Serial_Bus#Cabling

Mmmm Am I being picky? Sorry if I am but surely if we change cables then the filesize WILL change because if we dont change cables it will anyway?? I guess I am saying that simply seeing a change in filesize in this way can not be attributed to a cable and any test of this kind will not yield any conclusive results.

Lunch! ...

cheers

I think the point JD is making is that you can't say the change in cable is *not* responsible for a change in file size, at least in part.

Edit: sorry, JD's last post was not showing on my phone when I posted this.

 

[RobinKidderminster]

Job done then. meanwhile, back on the cable debate forum ! It surely is one that never goes away but if I had a penny ...

Cheers all

 

[AnotherJoe]

Scanners/printers use usb bulk transfer mode incorporating retry so the cable makes no difference (except in the number of packets that may have to be resent).

Data will only be lost over USB when using isochronous transfer mode which is typically used for realtime streaming.

 

[The_Lhc]

Data will only be lost over USB when using isochronous transfer mode

Do you mean "asynchronous"? And did you mean "will" or "can"?

 

[AnotherJoe]

The terms synchronous, adaptive, adaptive asynchronous, and asynchronous used by DAC manufactures have nothing to do with the underlying usb mode - they are purely to do with the synchronization between the source device and the DAC to avoid buffer overrun/underrun.

adaptive - means source timing rules apply

asynchronous - means DAC timing rules apply

USB modes are
isochronous transfers: at some guaranteed data rate (often, but not necessarily, as fast as possible) but with possible data loss (e.g., realtime audio or video).interrupt transfers: devices that need guaranteed quick responses (bounded latency) (e.g., pointing devices and keyboards).bulk transfers: large sporadic transfers using all remaining available bandwidth, but with no guarantees on bandwidth or latency (e.g., file transfers, printers, scanners)[/list]
Synchronous, adaptive and asynchronous adaptive DACS use an isochronus transfer.Some high end asynchronus dacs may use a proprietary form of bulk transfer but without the resending of missing/corrupt data.Errors do occur when using USB for streaming audio. The error correction tries to compensate.Can you hear this? That depends on whether the number of errors overwhelms the error correction enough to make an significant audiable difference.

 

[relocated]

Just to get back to your question while others are clawing each others eyes out.

No clawing going on here, since everybody seems to agree...

Well, almost everyone. Perhaps you have a blind spot to certain 'need to declare an interest' posts. :doh: :O