sergeauckland
pfm Member
Even then, easier still is to subtract the analogue output with one cable from that with a second cable. What's left is the difference, to the accuracy of the comparison process, which can be arbitrarily high.
S.
USB cable group test in HFN
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Even then, easier still is to subtract the analogue output with one cable from that with a second cable. What's left is the difference, to the accuracy of the comparison process, which can be arbitrarily high.
S.
darrenyeats
pfm Member
There be dragons! This audiophile paranoia is reaching silly levels now.
clivem2
pfm Member
More like dragoons. This thread has been crazy for ages anyway.
darrenyeats
pfm Member
Just buy a proper DAC that has proper isolation, or use optical S/PDIF or something, if you can't live with the doubt.
Or even better, change something that will make an actual difference. Buy some better speakers, or try moving your current speakers about in your room, or buy some acoustic treatment. Anything but this nonsense.
I'm off to listen to some music!
Darren
Or even better, change something that will make an actual difference. Buy some better speakers, or try moving your current speakers about in your room, or buy some acoustic treatment. Anything but this nonsense.
I'm off to listen to some music!
Darren
clivem2
pfm Member
Enjoy your music.
I'm very happy with what I have, my simple USB cable is great, the DAC is well isolated, have 2 excellent turntables, my speakers are really rather good. My room is treated though if we move house soon I hope for a larger room as 15' x 18' is about as small as my OBs can cope with even with room treatment. It's not me that has any doubts.
Some people believe cables make a difference, some don't.
As an engineer I can't see a way -any- can with competently designed components at audio frequencies, let alone USB cables.
OTOH if an enthusiast -can- hear a difference, imagined or not, it is real enough for the individual and it is his money to spend/waste as he sees fit...
IME those that can hear a difference think those that can't are deaf or undiscerning, those that can't, or believe that anybody hearing the impossible-to-exist difference are fools who deserve to be either separated from their money or "cured" by reasoning.
Does anybody know any keen enthusiast who has changed their opinion due to a cable thread in the internet?
As an engineer I can't see a way -any- can with competently designed components at audio frequencies, let alone USB cables.
OTOH if an enthusiast -can- hear a difference, imagined or not, it is real enough for the individual and it is his money to spend/waste as he sees fit...
IME those that can hear a difference think those that can't are deaf or undiscerning, those that can't, or believe that anybody hearing the impossible-to-exist difference are fools who deserve to be either separated from their money or "cured" by reasoning.
Does anybody know any keen enthusiast who has changed their opinion due to a cable thread in the internet?
clivem2
pfm Member
I hope so!
Whaleblue
Southbound
Well, is it?
Whaleblue
Southbound
Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world. (Albert Einstein)
Discuss
Please don't. I have a life I should be leading.
Mongeddavid
pfm Member
I borrowed a couple of USB cables from my local dealer today. Nothing esoteric but a supra cable and a chord both below £50.I have been using a maplins profgold usb cable prior to today. I am running Foobar via WASAPI from my pc into a Hiface Evo (battery powered) and Evo clock then via spdif to a metrum octave DAC. Rest of the system comprises a lightspeed LDR passive pre a 300b border patrol SET amp and a pair of LV Avatar speakers Mainly hooked up with some excellent MIL spec cables. I consider my system to be well matched / sorted and resolving of upstream differences if not exactly the latest cutting edge technology.
I can say that i have heard a difference in presentation between the two cables. The Supra sounds much like the Profgold Maplins cable. Strong bass and produces a wide sound stage with lots of detail. The chord sounds more focused with more texture to instruments it appears to be not as detailed or have as strong a bass but it does seem to be layering the mix of the music more and providing a more natural sound. Instruments being a tad more real as if a degree of bloom has been removed. Its not a huge difference but i swear that it is there. Now as to whether i would notice if someone came in and swapped round the USB cables is hard to say.
I am now convinced that there is a difference between USB cables whether a more expensive cable is necessarily better or indeed how much I would be willing to pay for a cable is something i will need to ponder but i do know that it is something i will investigate / experiment with further.
I can say that i have heard a difference in presentation between the two cables. The Supra sounds much like the Profgold Maplins cable. Strong bass and produces a wide sound stage with lots of detail. The chord sounds more focused with more texture to instruments it appears to be not as detailed or have as strong a bass but it does seem to be layering the mix of the music more and providing a more natural sound. Instruments being a tad more real as if a degree of bloom has been removed. Its not a huge difference but i swear that it is there. Now as to whether i would notice if someone came in and swapped round the USB cables is hard to say.
I am now convinced that there is a difference between USB cables whether a more expensive cable is necessarily better or indeed how much I would be willing to pay for a cable is something i will need to ponder but i do know that it is something i will investigate / experiment with further.
adamdea
You are not a sound quality evaluation device
Yes me, kind of. But I guess that was at a relatively early stage and it amounted changing my assumption that people wouldn't confidently assert stuff if there was no basis for it.
Mikas
pfm Member
Don't follow that road. If that was a reasonable explanation for losing bits at the low speeds audio needs, than we would have much higher rates of data loss at the much higher speeds computers use every day everywhere. And we don't.
I believe that's looking for explanations in the wrong place.
Again, USB cables don't need high spec electrical properties for such low data rates. Every cable will perform flawlessly unless broken.
Even with digital audio through USB, the bits are not sent as they are, they're sent within frames. Data loss can be easily measured.
Better than having people listening to the sound of digital cables, it would be much easier to use a computer measuring lost information (packets).
Make a copy of an entire FLAC album, let's say 1Gbyte from an external Hard drive to the internal drive of a computer through USB (it would take some seconds) and look for the packet loss percentage during the process. You should expect 0% at 150 Mbits per second or more (speed being limited by hard drives, not USB).
But what you're telling is that the same USB cable when used to play just a single track from that same album during 3 or 4 minutes, at 0.7Mbits per second (assuming a 96kHz 24 bits file), it will lose bits (corrupt packets)?
At 150Mbits per second, we have 0% losses.
At 0,7Mbits per second we find some?
How likely is that?
That said, due to the nature of streaming we can have data losses, but those are usually due to source problems (timing or reading accuracy on CDs for instance), not cables.
Just want to add this little detail: Data loss leads to jitter. Jitter can be easily heard by clicks or 'hiccups' in the music being played. It's not something subtle affecting things like soundstage or detail.
Michael
maxflinn
pfm Member
Probably not, I'll be e-mailing Paul Miller over the weekend, so hopefully, we'll get some answers.
Ill be very interested to read the reply if you get one.
He's clearly a talented engineer, but that doesn't necessarily sit well with selling ad space.
Whaleblue
Southbound
Michael,
I'm not sure you read my post the way it was intended. I am in the "USB data transfer does not need expensive cables" camp (let's leave aside noise carried by said cable and the possibility of the effect that might or might not have on DAC analogue aspects - think I'm in the "might not" camp there too though!).
The point of my post was intended to highlight was that "bits is bits" is not a valid argument per se, as wires don't do 1's and 0's but electrical currents. But yes, they do that admirably well as your retort details.
I'm not sure you read my post the way it was intended. I am in the "USB data transfer does not need expensive cables" camp (let's leave aside noise carried by said cable and the possibility of the effect that might or might not have on DAC analogue aspects - think I'm in the "might not" camp there too though!).
The point of my post was intended to highlight was that "bits is bits" is not a valid argument per se, as wires don't do 1's and 0's but electrical currents. But yes, they do that admirably well as your retort details.
Whaleblue
Southbound
adamdea
You are not a sound quality evaluation device
Actually they do do 0s and 1s but they basically do so in something a bit like morse code as I pointed out earlier. The code is robust and is very difficult to read incorrectly, rather like a 0 and a 1. There can be considerable variation in the carrier signal without there being any loss of information. Don't buy into this guff about digital signals really being analog: it is a conceptual and factual fallacy.
"Bits is bits" is not a helpful statement or slogan and it isn't an argument at all. What is helpful is to know that
a) a digital channel can convey information perfectly ie without any information loss whatsoever under very wide operating conditions and in the presence of noise and interference
b) the conditions necessary to prevent perfect transmission of information can be predicted accurately and established experimentally
c) it can be established fairly easily whether any corruption of data has taken place using parity bits, checksums etc.see also DTS test
This should not be news to anyone with an Mdac or a weiss.
adamdea
You are not a sound quality evaluation device
You're right about data loss causing clicks or hiccups, but I think you have kind of got the wrong end of the stick about jitter. This is not surprising as it's often bandied around rather vaguely- it's basically a timing error and one more usually refers to jitter (potentially) causing data loss rather than the other way round. However jitter can more significantly lead to information loss at the conversion stage.
It is supposedly the existence of jitter which means that a bit perfect S/PDIF transmission may yet produce an unsatisfactory result. This is supposed to be the problem for which asynch usb was the solution. But if you read the measurements accompanying the benchmark dac review in the famous July HFN edtion you will find that the S/PDIF input produces less jitter than asynch usb (near as dammit no jitter), which neatly explains why you never needed asynch usb in the first place.
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