USB cables , let talk about them.

[mantis]

Whats up all?
I've been wanting to give a higher quality USB cable a spin since I got into Computer music. I picked up a Audioquest Forest just to get the ball rolling. for a 1.5m cable it's only 30 bucks. Ok not a waste of money even if it does nothing better over my Belkin 6ft 2.0 high speed cable.

I recently picked up the Pioneer ELite SC-68 with the built in USB DAC. I have a Macbook Pro running Channel D software with Itunes so I can play .Flac High Rez files. This is very cool as I feel this setup sounds as good and better then SACD or DVD Audio. This is something I have been looking for since the fall of the 2 formats.

I first listened to my Jen Chaplin cut at 192k "You haven't done Nothin" . This cut is fanatically Dynamic and super clear. The Belkin sounds amazing with what appears to be everything in tact. No clarity problems and I think the entire signal is getting there perfectly. I have no problems with the way this sounds and I'm not really thinking the cable is hindering anything.
Then I swapped out the Belkin for the Audioquest and things changed. First off sounds are happening in different places. The Stand up bass seemed to favor the left channel and now it seems more centered to right channel. I also noticed more squeaks in the fingering with the Audioquest on the fret board. Something that happens when you play a string instrument. Some may thing it's annoying , some look for it , I just except it happens as I play guitar and it happens a lot.
The Audioquest doesn't seem so far to add any additional clarity other then what I noticed on the fret board. I also don't have a lot of time invested listening to each and swapping back and forth. I seem to send up enjoying the music and then get back to the demo. No night and day here as with speaker cables or IC's in the analog world.

Now I'm not sure if the Audioquest is doing something right or wrong. I know for sure it's different. I'm not willing at this time to say it's better or worse as both cables have a uncanny ability to show off the High Rez cuts. I'm gonna play around with some 16/44.1 cuts and report back. I'm also waiting on Cardas and Audioquest to hit our store so I have others to compare to. I have no idea how or why a USB cable would make any difference unless said cables are not properly built. It's passing digital signal and needs to do that job correctly. One or both of these cables are not doing the job right.

Anyone have any experience comparing USB cables? This is my only experience so far.

[thsmith]

Dan, I have tried testing quite a few and even built my own. I found it very hard to tell a difference but with a lot of testing and listening you start to note subtle differences. Some people have heard night and day differences, I am not one of those.

I have some DIY USB cables I made over the holiday with no power leads or shielding if you want to throw them in the mix. Both have 50 hours on them. One has wire from Pepster and the other one from VH Audio. Both are solid core silver.

[Toolfan66]

USB CABLE = The only cable that I have tried many with no changes..

[mantis]

Yeah I don't like the Polk photo uploader , that looks like crap , o well back to photobucket with forum links , that works much better.

Anyway , I did some track testing to listen to the actual disc's vs the rips on the computer vs the 2 USB cables I got here. I have found the Belkin USB doesn't place everything where it's supposed to be. How is that even possible? That cable works , I get no errors using it , it's not that old , maybe 2 years as I have used it for computer uses. It's USB 2.0 high speed and only 6 feet long.
Other then that I don't really hear anything different switching out the cables. I tried and tried again. I'm not finding to much benefit other then getting things in the right order which I can't explain why one cable does and one doesn't . Must be some stricker tolerances at Audioquest then Belkin for computer cables. I'm a little on the fence with my findings. But what was true is the Audioquest Forest USB cable did place everything exactly as it is on the cd's. I used Norah Jones both SACD and CD both running in just 2 channel mode as the first time I put the SACD in it went to multichannel. That sounded completely different as I didn't catch it right away , it was about 10 seconds in the cut where I realized it was in multichannel.

[mantis]

Dan, I have tried testing quite a few and even built my own. I found it very hard to tell a difference but with a lot of testing and listening you start to note subtle differences. Some people have heard night and day differences, I am not one of those.

I have some DIY USB cables I made over the holiday with no power leads or shielding if you want to throw them in the mix. Both have 50 hours on them. One has wire from Pepster and the other one from VH Audio. Both are solid core silver.

Fill me in again , what does removing the power do? doesn't it need the power? I'd like to try them out if your willing to send them here. I'll pay for the shipping , just let me know how much it was to ship and I'll send you the money. I'll send them back after 1 week of testing.

[mantis]

USB CABLE = The only cable that I have tried many with no changes..

Assuming all the cables you had where built to the standard , I can see this being very true. I'm learning this as I go. I feel like a rookie LOL. I have spend 0 time learning about USB cables and the effect they could possibly have on the audio signal other then reading manufactures ads.

[thsmith]

Fill me in again , what does removing the power do? doesn't it need the power? I'd like to try them out if your willing to send them here. I'll pay for the shipping , just let me know how much it was to ship and I'll send you the money. I'll send them back after 1 week of testing.

My Dac does not require power from the USB Cable. Suppose to eliminate noise and I/F..


Send me your address and I will get them out in the mail, no worries on shipping. They are only about 20" long so make you can use them. Supposedly shorter the better.

The one with one blue wire and 2 white are from VH Audio And the white insulation is very easy to strip, almost like Cotten.

[mantis]

My Dac does not require power from the USB Cable. Suppose to eliminate noise and I/F..


Send me your address and I will get them out in the mail, no worries on shipping. They are only about 20" long so make you can use them. Supposedly shorter the better.

The one with one blue wire and 2 white are from VH Audio And the white insulation is very easy to strip, almost like Cotten.

Clean out your PM , your inbox must be full

[thsmith]

Cleaned out

[Tbone289]

My Dac does not require power from the USB Cable. Suppose to eliminate noise and I/F..

If your DAC doesn't require power from USB, then there is no current present on the power conductors in the USB cable. Do you have any thoughts on why power conductors that are carrying no current would increase noise and I/F on the data lines in the USB cable?

[thsmith]

If your DAC doesn't require power from USB, then there is no current present on the power conductors in the USB cable. Do you have any thoughts on why power conductors that are carrying no current would increase noise and I/F on the data lines in the USB cable?

Just because it is not needed does not mean it is not present.

[Tbone289]

Just because it is not needed does not mean it is not present.

So, the DAC is creating potential in the DC USB circuit even though it doesn't require DC USB power? Or is this current that may be present induced by the data lines?

[thsmith]

All I know is, it is not needed in my case and it cost additional money to run it. YMMV

[Tbone289]

All I know is, it is not needed in my case and it cost additional money to run it. YMMV

Well, that is certainly true. I was just wondering how they could affect noise as you mentioned earlier. Mine doesn't require power from the USB circuit either, but never had the thought that the power lines could cause noise in that case.

Thanks.

[thsmith]

All I know is, it is not needed in my case and it cost additional money to run it. YMMV

[txcoastal1]

In most cases there is always power at the USB port which carries through your cable. The device plugged into USB port may not have the internal pwr connection wiring if it does require it.

USB does not work like poe which has a chip at the switch and device end calling for power.

[Tbone289]

In most cases there is always power at the USB port which carries through your cable. The device plugged into USB port may not have the internal pwr connection wiring if it does require it.

There is no power going through the cable if there is no internal power connection in the USB device. This would be the same as positive and negative wires connected to a battery and nothing else. There is no circuit/no load, so there is no potential to induce voltage/current through the wires.

[mantis]

I never dug into USB to think about the voltage adding noise to the signal. It's part of the design of USB so I would assume it's been dealt with. This is something I'm gonna look into and see what I can come up with. It's interesting as avoiding noise is always a good thing.

[pepster]

I never dug into USB to think about the voltage adding noise to the signal. It's part of the design of USB so I would assume it's been dealt with. This is something I'm gonna look into and see what I can come up with. It's interesting as avoiding noise is always a good thing.

The noise comes from the computer supplying the power and the noise associated with the noise internally in a computer (which is quiet a bit).
If you use a wall wart or outboard power supply there is ALOT less noise than a computer.

I cannot speak for that personally, but that is the idea.
Not to mention the little gained from from not running 5v power wires in parallel to digital signals.

Personally, I just do not consider USB an audiophile connection.

[Tbone289]

If the USB device is powered externally and has no power connection to the USB interface, there will be no power in the USB cable AT ALL--only data. So, in that case, removing, altering or improving the cable in hopes of reducing noise from the power wires will have no impact.

The only possibilities of altering a digital signal through a cable is to introduce bit errors or jitter (timing errors). A USB cable can carry binary data as accurately as coax. Your money would be better spent upgrading from a DAC with an inferior USB interface (synchronous or adaptive) to a superior interface (asynchronous) than to spend money on an expensive cable. The interface upgrade would have more of a positive impact on error reduction than the cable. If you are using an asynchronous interface, you might consider a better cable if jitter is still somehow an issue.

[pepster]

If the USB device is powered externally and has no power connection to the USB interface, there will be no power in the USB cable AT ALL--only data. So, in that case, removing, altering or improving the cable in hopes of reducing noise from the power wires will have no impact.

The only possibilities of altering a digital signal through a cable is to introduce bit errors or jitter (timing errors). A USB cable can carry binary data as accurately as coax. Your money would be better spent upgrading from a DAC with an inferior USB interface (synchronous or adaptive) to a superior interface (asynchronous) than to spend money on an expensive cable. The interface upgrade would have more of a positive impact on error reduction than the cable. If you are using an asynchronous interface, you might consider a better cable if jitter is still somehow an issue.

That is not entirely true, most components use usb power supplied from your computer in a USB interface.
Fewer use external power supplies (wall wart ect).

That said, ANY audio signal (including analog) is directly affected by AC or DC current running in parallel wires to the signal (even Data packs).
Electrical wires are going to induce noise (AC or DC).

[Tbone289]

That is not entirely true, most components use usb power supplied from your computer in a USB interface.
Fewer use external power supplies (wall wart ect).

Please read my post again. I was speaking purely of the ones that are externally powered in the first paragraph. That is why I said (with emphasis added in bold), "If the USB device is powered externally and has no power connection to the USB interface, there will be no power in the USB cable AT ALL--only data. So, in that case, removing, altering or improving the cable in hopes of reducing noise from the power wires will have no impact."

Was that unclear? The rest of what I said is true in either case (externally powered or powered by USB).

That said, ANY audio signal (including analog) is directly affected by AC or DC current running in parallel wires to the signal (even Data packs).

Right. No argument there.

[pepster]

I must have misread.
My apologies.

[Tbone289]

I must have misread.
My apologies.

No worries. I do have a couple of USB-powered portable DACs (asynch), and I prefer to use a USB cable with a ferrite bead on it with those for a little peace-of-mind if nothing else.

[pepster]

Sorry about that, I even quoted you and still did not connect the dots.
They didn't "Learn Me" to read good when I was a youngin!

[pepster]

I never dug into USB to think about the voltage adding noise to the signal. It's part of the design of USB so I would assume it's been dealt with. This is something I'm gonna look into and see what I can come up with. It's interesting as avoiding noise is always a good thing.

It would make more than a little sense to me that removing the power wires would remove heat and thus noise.
Now whether you can tell a difference is subjective for sure.

[mantis]

It would make more than a little sense to me that removing the power wires would remove heat and thus noise.
Now whether you can tell a difference is subjective for sure.

In the analog world , when you compare balanced to unbalanced , it's pretty noticeable the lower noise floor. The Balanced cables basically have no noise at all and give you that silent between the notes where as unbalanced cables tend to have a slight hiss. This is noticeable when you compare average unbalanced to any balanced , even standard cheap balanced cables.

As soon as I get a minute , I'm gonna contact Audioquest and Cardas. I might even talk to Kimber as they are our top 3 wire companies.

[thsmith]

Dan, 2 DIY USB cables going in the mail today.

Both have solid silver wire ~24" long and no power lead. DO have grounds on both ends and no shielding.

[mantis]

Dan, 2 DIY USB cables going in the mail today.

Both have solid silver wire ~24" long and no power lead. DO have grounds on both ends and no shielding.

Very cool , I'll take good care of them and return them 1 week or so after I receive them.
This is going to be fun.
Thank you so much.

[thsmith]

Take your time Dan, I think you are on a roll and am interested in what you hear with these, or maybe dont hear.