[CharlesC]

Ok. I get the whole bit about digital info vs. analog info but I'm particularly interested in USB powered DAC/Amps so I've gotta ask. My rather unscientific observations tell me that the performance of these devices varies with the amount of power that they receive from the source. So my question is, over about 18" from the same source, could one usb cable provide appreciably better power to a usb powered DAC/Amp than another?
 
If so, then I guess devices like the Dragonfly and Audioengine D-3 that can plug directly into the USB port of the source would have a slight advantage in the portable wars.
 
Thanks.

 

[mikeaj]

The amount of power drawn depends on the design of the external USB device and very little on the host device and cable. I guess if you're talking about performance, yes, it's easier to get better performance and especially higher output power (note: higher output power gives you higher volume, and if comparisons are not level matched, the louder device usually wins) if you're allowed to draw more power. You don't need to make as many compromises in terms of topology and going for especially low-power electronics if not being as frugal. However, the time and quality of design and effort of the design team matter more than one design constraint like power consumption: you should easily be able to find lower-power stuff outperforming higher-power stuff.
 
"Appreciably better" depends on whether you're talking about machine-measurable, human-perceivable, or human-preferable. With good enough bench gear and the right conditions and downstream device you may get something measurably different. For one, if the wires are very thin (though this matters a lot less over 18" of wire), there could be some larger voltage drop across them, so the DAC/amp gets less and perhaps does a worse job at regulating voltages and so on, which could affect the outputs in some small way. You could get some EMI as well. A ferrite bead is probably not a bad idea.
 
I'd be very much more concerned about the electronics and layout of the DAC/amps than miniscule details about power delivery. Also, if you're going to be playing the theory game and talking about ones that plug in directly, you might say they're closer to sources of interference from the host computer.
 
 
In any case, with respect to power, look first at the audio electronics and its susceptibility to issues. Then at the power supply filtering on the DAC/amp. Then at the quality of power from the host device. Then way down the list of importance is anything to do with the USB cable aside from whether or not it's plugged in.

 

[StanD]

+1
Unless you bought a junky cable, like it's been said, last on the list. You will not get a better soundstage or treble or whatever by spending gobs of cash on fancy USB cables. Either it will work or not. A junky cable might be more susceptible to interference/induced noise.

 

[Lorspeaker]

my own answer  is simple..just buy one with a 30day return n try it out on my system..
if it sounds good, i keep it..otherwise i  return it.

 

[CharlesC]

Thanks.  Sounds unanimous.  I love asking questions on the Sound Science board.

 

[cswann1]

Here is a quote from a retailer of high-end cables, taken from their website's page on their $75 usb cable.
 
"Standard USB cables are not up to the task of large bit rate information."
 
This is a blatant lie.  Any USB cable that is capable of connecting the pins of two USB ports is perfectly capable of whatever bit-rate the USB port provides.  The cable is nothing more than wires to get an electrical signal from one place to another.  Because we're talking about audio information that is still in the digital domain, the "quality" of the zero's and one's is irrelevant.  As a matter of fact there is no such thing as higher or lower quality digital information, hence the quotes.

 

[StanD]

  Here is a quote from a retailer of high-end cables, taken from their website's page on their $75 usb cable.
 
"Standard USB cables are not up to the task of large bit rate information."
 
This is a blatant lie.  Any USB cable that is capable of connecting the pins of two USB ports is perfectly capable of whatever bit-rate the USB port provides.  The cable is nothing more than wires to get an electrical signal from one place to another.  Because we're talking about audio information that is still in the digital domain, the "quality" of the zero's and one's is irrelevant.  As a matter of fact there is no such thing as higher or lower quality digital information, hence the quotes.

+2 

 

[Mambosenior]

Here is a quote from a retailer of high-end cables, taken from their website's page on their $75 usb cable.

"[COLOR=939598]Standard USB cables are not up to the task of large bit rate information.[/COLOR]"

This is a blatant lie.  Any USB cable that is capable of connecting the pins of two USB ports is perfectly capable of whatever bit-rate the USB port provides.  The cable is nothing more than wires to get an electrical signal from one place to another.  Because we're talking about audio information that is still in the digital domain, the "quality" of the zero's and one's is irrelevant.  As a matter of fact there is no such thing as higher or lower quality digital information, hence the quotes.

I guess then that their $75. USB cable's connecting pins and wire must be made of more exotic materials than found on Monoprice's $5. USB cable (sarcasm intended).

 

[StanD]

I guess then that their $75. USB cable's connecting pins and wire must be made of more exotic materials than found on Monoprice's $5. USB cable (sarcasm intended).

No, just higher profit margins and a BS story. (No sarcasm intended) 

 

[Mambosenior]

  No, just higher profit margins and a BS story. (No sarcasm intended) 

A person can get better written “stories” in the Science Fiction aisle at Barnes and Noble?

 

[StanD]

  No, just higher profit margins and a BS story. (No sarcasm intended) 

 
 

 
A person can get better written “stories” in the Science Fiction aisle at Barnes and Noble?

I've seen better stories in the tabloids at the supermarket about two headed babies whose mothers had sex with aliens during a nightly abduction. I think one story had a baby born with a USB cable in hand.