Jocko Homo wrote some sensible stuff about the digital cable subject. I can't remember if it was here, over at diyhifi, or at AA. It has something to do with impedances and reflections, but I can't recall the detail.
The upshot was that changing a digital cable can make a difference under certain circumstances, but not to the level over-hyped by the adolescent marketing monkeys.
The upshot was that changing a digital cable can make a difference under certain circumstances, but not to the level over-hyped by the adolescent marketing monkeys.
Re: Re: Re: Re: I Just Got Flamed In The AudioAsylum!
Not in all implementations. USB has different modes that can be used. Implementations that use async USB mode can get away without PLL clock reconstruction. The E-MU 0404 USB is one example. This is, admittedly, a rare case and requires special software drivers to be written. But there are such implementations out there.
analog_sa said:
Not in all implementations. USB has different modes that can be used. Implementations that use async USB mode can get away without PLL clock reconstruction. The E-MU 0404 USB is one example. This is, admittedly, a rare case and requires special software drivers to be written. But there are such implementations out there.
Me too! Man, we are so awesome.binarywhisper said:
binarywhisper said:
I stand by my statement. USB 1.1 audio transfer works fine over $5 cables. Heck, it'll work fine over the free cables that come with most USB devices.
binarywhisper said:
Please provide a reference showing significantly increased BER on cheap USB cables for USB 1.1 (not USB 2.0).
binarywhisper said:
It must be great always being the smartest guy in the room. "Error correction routines aimed at packets of data, not audio"? The routines are identical, as bits are bits. What differs is that the USB protocol itself does not specify retransmission for the audio profile (isochronous delivery). I'll slow that down so everyone can understand it: there is nothing special about the error correction algorithms that are used for the USB audio profile, the standard just doesn't call for retransmission of corrupt packets for isochronous transfers.
See, that wasn't so hard to explain, was it?
binarywhisper said:
Given that the USB profile involved in syncing your PDA does, in fact, retransmit corrupted packets (bulk delivery), that makes no sense. The difference is obvious to anyone with the training and almost impossible to explain to anyone without.
binarywhisper said:
But $550 and quantum tunneling ..damn, thats some funny crap. I guess everyone needs a hobby
edit.........................
I just thought I should come back to this and say a decent good USB cable can be had $30 and I personally would be comfortable using that for data or audio.
Awesome, I just figured out how to turn a $25 profit! Everyone wins!
binarywhisper said:
To be honest, when I first read this I thought you meant $5 for a usb cable is also too much. I don't know why you wouldn't use a $1 cable.
Someone already pointed out how ridiculous this is, but I can't resist. This is hilarious.
I am a couple months shy of a BS in computer engineering. Explain.
What does that have to do with usb cables?
Seriously.
Here's some details on USB audio: http://www.audioasylum.com/forums/pcaudio/messages/7719.html
(Yes, somewhat ironic that it comes from the same place.)
According to this guy, there are 3 different synch modes:
1. Synchronous. Uses a PLL to get the sample rate from the 1 kHz frame rate.
2. Adaptive. Uses some sort of VCO/PLL deal that matches the data rate coming in.
3. Asynchronous. Basically a FIFO. Self-clocked.
Apparently most USB DACs are of type 2, adaptive.
Given that the data coming in over the USB bus is up to the whim of the host, I suspect the VCO/PLL in an adaptive DAC is the limiting factor. Seems like a lousy scheme for audio, no matter how perfect your path to the host is.
(Yes, somewhat ironic that it comes from the same place.)
According to this guy, there are 3 different synch modes:
1. Synchronous. Uses a PLL to get the sample rate from the 1 kHz frame rate.
2. Adaptive. Uses some sort of VCO/PLL deal that matches the data rate coming in.
3. Asynchronous. Basically a FIFO. Self-clocked.
Apparently most USB DACs are of type 2, adaptive.
Given that the data coming in over the USB bus is up to the whim of the host, I suspect the VCO/PLL in an adaptive DAC is the limiting factor. Seems like a lousy scheme for audio, no matter how perfect your path to the host is.
Not surprised. This is typical of AA. If you want to avoid all manner of nastiness at AA never, EVER write anything at all about cables.
It's even a bit dicey to opine that your $500 cable sounds better than someone else's $500 cable.
To be honest, if I spent that much on a cable the last thing I would want to read would be even a hint that maybe I wasn't getting what I paid for. I have to say, however, the colors and patterns certainly look impressive. In fact, I really like the the blue LED USB cable that runs to my printer.
$550 usb cable, to me, sounds lots of money. I'll just stick with my $1 cable as it already sounds really nice. But I don't mind to do the audition if I have a chance. I would think the difference will be minimal, same as CD/CDR issue. If I can't spot the difference, there will be no point going for that cable as my DAC is defective. 
For the bus powered application, I think it would benefit a bit like changing your amp's power supply wirings.
For the flaming issue, there will be at some stage that you will just don't care about it anymore. People are different. Breaking their beliefs and you really break their heart. The flaming doesn't pay your bills btw.
For the bus powered application, I think it would benefit a bit like changing your amp's power supply wirings.
For the flaming issue, there will be at some stage that you will just don't care about it anymore. People are different. Breaking their beliefs and you really break their heart. The flaming doesn't pay your bills btw.
Don't waste your time arguing with potential $550 USB cable buyers...
Sell $550 USB cables to them!! You only have to design a fashionable looking product, find a suitable manufacturer in China ($1 per cable) and invent some pseudo-scientific claims. Buying some positive reviews in well known media is of great use too.
In the end you make them happy with their cable and they make you happy with their money. It's one of the best business ever invented, you can make a very relaxed life out of fool's money
Sell $550 USB cables to them!! You only have to design a fashionable looking product, find a suitable manufacturer in China ($1 per cable) and invent some pseudo-scientific claims. Buying some positive reviews in well known media is of great use too.
In the end you make them happy with their cable and they make you happy with their money. It's one of the best business ever invented, you can make a very relaxed life out of fool's money
b-square said:
Google for 'cosmic pipes' the agricultural version of this. I'm sure SY approves.
As for the subject at hand, I thought the sample rate converter on many USB audio devices was a bigger problem. They almost guarantee non-bitperfect data transfer. I've used an ASIO device to do simultaneous A/D - D/A over the same USB connection ($15 Costco cable) and never noticed any problems.
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