aardvark baguette Posted June 2, 2009 Report Posted June 2, 2009 they can cause protocol errors. Solution:
Hopstretch Posted June 2, 2009 Report Posted June 2, 2009 Cock wart. OK, I'm bored and trawled around a bit. Here's what Gordon Rankin has to say about testing different USB cables and why their physical design might make a difference. Please note I'm not advocating for this position, so kindly don't throw feces at me. Here is how I test cables: Computer ====== USB UUT =====>USB Analyzer===>TI TAS1020B DEV Board & Emulator I usually get a 5M cable for testing. I can set the Unit Under TEST between my USB Analyzer and the TI DEV board. In my code for the TAS1020B I have error counting enabled and therefore I can set the computer up to send say a Sine wave at 1KHz. Then see the errors via the USB Analyzer and the TI DEV board. I can run the test between 44.1 and 96k at 24 bits and get an idea of how the cable preforms. At 44.1 there is basically 264.6 bytes transfered every 1ms. Actually it does something like 9 packets at 264 and one packet at 270. This happens either on the MAC or the PC. At 96k it does 576 bytes ever 1ms. By using the longest cable you can better see how it would work at shorter distances. This would not be normally true of network cables as distance can screw with results. But with USB this is pretty easy because the cable distance is only a max of 5m. The geometry of the data section of the cable can make or break audio. MSOF's that happen will throw off the calculations for the derived clock. Also errors in packet data can happen. The shielding adds capacitence which can slow down the waveform. The eye patteren (data+ and data- shown on an oscilloscope) can also show how well a cable preforms. I have not talked to Ray about his use of Ferrites on the cable but as we can conclude all pc's have switching power supplies and the ferrites on both ends will repel high frequency radiation from entering the receiving endpoint (dac in this case). It was shown by Guido Tent that the use of Ferrites in digital audio was a good thing. Guido worked for years in the Phillps R&D to determine ways of reducing jitter and noise in digital & video systems. Guido likes to use ferrites between components to reduce jitter and noise in regulated systems. You can read some of Guido's work on his website at TentLabs.com. He seems to have changed his mind about ferrites after actually testing them, though, as I found this from a year later. I would not suggest the Belkin AV, not at all a good choice, there standard gold is much better. Putting ferrites on the cable actually causes protocol errors. We found this out with the more expensive Kimber. We cut the ferrites off and the errors went away. They are now offereing that cable without the ferrites.
jimmyjames8 Posted June 2, 2009 Report Posted June 2, 2009 Can you recommend me the best one for use with pc to NOS DAC Office Depot carries the Belkin brand and my closest OD has 3 flavors of Belkins, two with gold plating which does seem to be a better electrical/electronic termination metal. Don't know about the wires inside. The mid grade with gold plate seems to work well in my modest PC sound system. All under $60. There is a shoot out of USB cables floating around somewhere in cyber space and the Belkins were in the mix.
luvdunhill Posted June 2, 2009 Report Posted June 2, 2009 Yes. You need to ensure that these are bandwidth limited so the bits don't go too fast and pull you out of NOS... . exactly! NOS USB cable with "Power Wraps" from Percy on both ends is what I'd recommend. Use the spacing of the Power Wraps to tune the sound to your particular preference. I find 0.5" spacing to be the best for rock and e^-1 spacing better for classical.. but it's nice to be able to change them on the fly.
aardvark baguette Posted June 2, 2009 Report Posted June 2, 2009 I have an Amish-like mentality, in regards to the errors. Too few errors, and the music is not natural, and too artificial. You need a little bit of edginess from occasional errors to help make the audio sound natural, and real. I only use usb cables intentionally designed to induce protocol errors. Nobody makes USB cables better than the Amish.
spritzer Posted June 2, 2009 Report Posted June 2, 2009 Am I in the twilight Zone or in an audiophile forum??? ermmm seacrest out This is an audiophile forum but what you are looking for is an audiophool forum filled with people that buy anything without questioning it. That's what HF is, so go there to ask stupid questions like this...
Hopstretch Posted June 2, 2009 Report Posted June 2, 2009 I tried, but knew it would turn ugly. Oh cables, how long must your dielectrics divide us? How onerous the shiny coils which weight our discourse!
donunus Posted June 2, 2009 Author Report Posted June 2, 2009 Can you tell me why its a stupid question? I thought cds/pcm data played real time and errors are not corrected during the stream which is why usb cables dont sound the same for playing audio. I can definitely even get a perfect score a/b testing between two usb cables I currently have... having someone else switch the cables around. Anyway, its all good. I just got a belkin gold for now.
Spiug31 Posted June 2, 2009 Report Posted June 2, 2009 Can you recommend me the best one for use with pc to NOS DAC use a normal/affordable one, clean the contacts if you fancy but the next step up from a standard usb cable as far as features go would probably be one that provided galvanic isolation so you don't get ground loops. Oh cables, how long must your dielectrics divide us? How onerous the shiny coils which weight our discourse! round of applause
manaox2 Posted June 2, 2009 Report Posted June 2, 2009 Belkin gold works perfectly well. USB doesn't do error correction in the cable, but the protocol and receiver usually does use the error detection to detect and request that any data with errors be resent which may increase jitter. But really, it seems like it would have to be a piss poor cable to have many errors at all, any cable that meets USB specifications should be fine in my book as a decent receiver would likely buffer the data as well.
MoonShine Posted June 2, 2009 Report Posted June 2, 2009 Just make sure the cables are constructed without any nasty "fidelity absorbing" material.
deepak Posted June 2, 2009 Report Posted June 2, 2009 Can you tell me why its a stupid question? I thought cds/pcm data played real time and errors are not corrected during the stream which is why usb cables dont sound the same for playing audio. I can definitely even get a perfect score a/b testing between two usb cables I currently have... having someone else switch the cables around. Anyway, its all good. I just got a belkin gold for now. i call
Cankin Posted June 2, 2009 Report Posted June 2, 2009 hey, this isn't your typical headphone forum I'm too late this time
aardvark baguette Posted June 2, 2009 Report Posted June 2, 2009 I tried, but knew it would turn ugly. Its not ugly; its beautiful fun discourse
Nebby Posted June 2, 2009 Report Posted June 2, 2009 Actually it's better to have tin ears, it's easier on the wallet.
purk Posted June 2, 2009 Report Posted June 2, 2009 Actually it's better to have tin ears, it's easier on the wallet. Agreed!
Smeggy Posted June 2, 2009 Report Posted June 2, 2009 I have 99.999 OFC ears, they transmit the noise more better.. unfortunately they're attached to my lead brain.
aardvark baguette Posted June 2, 2009 Report Posted June 2, 2009 I have 99.999 OFC ears, they transmit the noise more better.. unfortunately they're attached to my lead brain. I hear in the digital domain.
ph0rk Posted June 2, 2009 Report Posted June 2, 2009 Actually it's better to have tin ears, it's easier on the wallet. And how. Or just do what I do: drink liberally before listening ...also posting.
screaming oranges Posted June 2, 2009 Report Posted June 2, 2009 tin-eared sluts and golden-eared sluts. sluts nonetheless. one is just high maintenance.
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