[hugoboss]

Hello All,
Iam doing some small project now with usb cable for dac to pc computer. 
Strange Thing Happen.
 
 
1. When I use all 4 cable from pure copper multi strand 24awg  signal +, Signal - , 5volt , Ground so 4 copper cable all
the sound is perfect no problem
2, When I use all 4 cable from pure solid silver 24awg. so many problem exist
crackling sound, dac device not detected, if detected the sound is full crackle. noise
3. Now the starnge thing I combine 4 cable from copper with 4 cable from pure silver
The SOUND IS FINE! same like using 4 copper
4. itry another combination signal + and - with pure silver. 5volt and ground with copper
again noise, crackle happen

anybody here experince this problem yet with diy usb cable?
plz advice me anything maybe iam doing something wrong


 

 

[ab initio]

  Hello All,
Iam doing some small project now with usb cable for dac to pc computer. 
Strange Thing Happen.
 
 
1. When I use all 4 cable from pure copper multi strand 24awg  signal +, Signal - , 5volt , Ground so 4 copper cable all
the sound is perfect no problem
2, When I use all 4 cable from pure solid silver 24awg. so many problem exist
crackling sound, dac device not detected, if detected the sound is full crackle. noise
3. Now the starnge thing I combine 4 cable from copper with 4 cable from pure silver
The SOUND IS FINE! same like using 4 copper
4. itry another combination signal + and - with pure silver. 5volt and ground with copper
again noise, crackle happen

anybody here experince this problem yet with diy usb cable?
plz advice me anything maybe iam doing something wrong
 
 
 

Have you tested your work with a multimeter to check basic things like good solder connections, no short circuits, no open circuits?
 
Secondly, USB defines criteria for compliant cables to allow all compliant devices to communicate perfectly. If you don't have the equipment to check for issues, then it will be pretty difficult to verify whether or not your DIY cable is meeting the right criteria.
 
Once you connect the working copper USB cabling in parallel with the silver cabling, the silver cabling become irrelevant (unless there's a short) because the signals can easily propagate through the copper. Because things work when you have copper in parallel with the silver, you can probably rule out a short in the silver cable.
 
Can you tell us what wire you are using and where you got it? is the copper cable just a manufactured USB cable and the silver is DIY? Are you shielding, twisting, etc.? Are you using a choke?
 
Cheers

 

[hugoboss]

i already check with digital multimeter , no short at all in the signal plus minus, 5volt, ground
all fine with multimeter.
 
iam using popular good neotech cable 24 awg.
 
it is bulk cable from, neotech and it is expensive
 

 

[hugoboss]

the cable is teflon dielectric, also i have try twisting method, straight method still if only silver cable used the crackle , noise is happen
 

 

[Speedskater]

What SY and others think about:
 
Teflon and Wire
****************************
Quote:
Originally Posted by multi-volti
Microphonic or triboelectric?
Triboelectric. Silver and Teflon is a particularly bad combination.
******************************
Since I've experimentally observed tribo effects in PTFE-silver interconnects, I will have to respectfully disagree. The rubbing comes between the conductors and the insulators as the cable is stressed (in a mechanical sense).
******************************    
PTFE and silver are also on the opposite ends of the triboelectric series. It's pretty easy to generate enough charge to create a significant transient voltage across high-ish impedances. This isn't DC, remember- if charges have a path to dissipate, they'll take it.
I've told the story several times on this forum about how I accidentally discovered this. It was quite embarrassing.
*******************************
Charges are created by triboelectricity- that's just plain well-known physics. They will discharge according to basic E&M- again, just plain well-known physics. The discharge is a transient signal, ditto. PTFE and silver are a combination particularly prone to triboelectric charging, ditto. You do not need a difference in the field along the cable, and in fact, when transmitting desired signal, there's no significant field along the cable- the triobo charges discharge across the Thevenin equivalent resistance of source and load in parallel, producing a spurious input voltage which is amplified by succeeding stages, ditto.
Now if you have a better explanation of this cable microphony which goes away when switching to PVC/copper, and it's based on physics, I'm all ears.
*******************************
No, and probably yes. Teflon's main advantage is heat stability. If that's worth the premium to you, go for it. Avoid anything marketed to audiophiles, use industrial wire- same stuff without the gullibility tax.
******************************
Microphonic DIY Interconnect Suggestions?
I recently built a set of single silver conductor shielded interconnects. I used teflon tube slightly larger than the silver wire on the assumption that a little air around the wire would add to the insulating powers of the teflon. Not sure if the rest of the construction matters, but the layers went: silver/teflon tube/teflon tape/copper conductor/larger teflon tube/copper drain/aluminum foil/shrink tube.
Anyway, to my dismay I've discovered that the interconnects are microphonic. If I bump or even touch them I hear it. I assume (!) it's the movement of the silver in the airspace of the smallest teflon tube. Has anyone here come across this? I hate to take them apart and modify them only to find the airspace wasn't the issue.
neddyboy
Yes, I have. Tribolectricity is my hypothesis- the cure is the same, use polypropylene or vinyl instead of Teflon.

 

[hugoboss]

@speedskater
 
so in your advice the cause of the pure silver cable cause crackle sound is because it use teflon ?
the copper cable iam tested also use teflon. why it's not effected like the silver.
 
i also tried building inetrconnect rca cable with the same pure silver cable, the sound is very good not a single crackle one like the usb cable

 

[ab initio]

  @speedskater
 
so in your advice the cause of the pure silver cable cause crackle sound is because it use teflon ?
the copper cable iam tested also use teflon. why it's not effected like the silver.
 
i also tried building inetrconnect rca cable with the same pure silver cable, the sound is very good not a single crackle one like the usb cable

rca interconnects and USB cables are completely different beasts. the requirements for good for digital communication is not necessarily the same as the requirements for low-level analog signals.
 
Cheers

 

[alexsv]

The use of Teflon is probably not the problem.
 
The D+ and D- conductors should be twisted at around 4 twists per inch as should the power leads in order to eliminate crosstalk.  The shield should be crimped to the USB housing and soldering is even better. As was pointed out before, there is no resemblance between analog interconnects and USB cables. The effectiveness of the dielectric that separates the power legs from the data legs is also important. Most USB cable designs shield the data separately from the power.
 
If the cable you are using was designed for anything but USB, you'll have problems.

 

[hugoboss]

@ALEXSV thanks for your advice
later i will try to add aluminium foil tape wraping the cable and using some shield from braided copper
will report later.


 
another question, is the shield braided cooper must solder in both end of the usb plate or just one end?
also if only the data plus minus that must shield right? 5v power and ground no need to shield is that right or all 4 cable must be shield together?

 

 

[alexsv]

  @ALEXSV thanks for your advice
later i will try to add aluminium foil tape wraping the cable and using some shield from braided copper
will report later.


 
another question, is the shield braided cooper must solder in both end of the usb plate or just one end?
also if only the data plus minus that must shield right? 5v power and ground no need to shield is that right or all 4 cable must be shield together?

 

Yes the braided copper shield needs to be soldered to BOTH housings. It's important for the data conductors to be shielded but it's easier if you apply the braided copper shield over all 4 wires. You can also apply the foil tape to the data wires only and there is no need to attach the foil to the housings if you are also applying a braided copper shield. Many USB 2.0 devices won't sync unless there is a shield present. Also remember to twist the data wires at a minimum of 3 twists per inch. This is critical. 

 

[hugoboss]

Advice taken. And thanks so much itis workingnow.

First i tried to twist like your said for 3 twist per inch without coppe braided. It work but some noise still exist.

After trying adding braided copper the noise completely gone, the sound is so good. Thanks again

 

[dvw]

USB cable is a digital cable. The impedance of the cable is critical. Unless the cable you used is compliant to the USB specification, it will be a hit and miss. The crackle you're hearing is the bit error. And the worst case of a bit error is that the USB device will not sync. DIY a USB cable is a challenge. There is really nothing to gain by doing a DIY cable. If you must do one, keeping the cable short will help.

 

[Speedskater]

  USB cable is a digital cable. The impedance of the cable is critical. Unless the cable you used is compliant to the USB specification, it will be a hit and miss. The crackle you're hearing is the bit error. And the worst case of a bit error is that the USB device will not sync. DIY a USB cable is a challenge. There is really nothing to gain by doing a DIY cable. If you must do one, keeping the cable short will help.

How very, very true.

 

[goodvibes]

  Yes the braided copper shield needs to be soldered to BOTH housings. It's important for the data conductors to be shielded but it's easier if you apply the braided copper shield over all 4 wires. You can also apply the foil tape to the data wires only and there is no need to attach the foil to the housings if you are also applying a braided copper shield. Many USB 2.0 devices won't sync unless there is a shield present. Also remember to twist the data wires at a minimum of 3 twists per inch. This is critical. 

I'm curious as to why both housings need grounding. Is the chassis not in parallel with one of the leads? Might actually increase noise with multiple paths if so. I'm not arguing but asking here.

 I'm unfamiliar with USB protocols or cable requirements.

 

[hugoboss]

i diy my own usb cable because a good pure silver cable is still more more cheaper than a finished one the price is 3times
also i dont know anything about cable impedance. just trial and error.
 
but trust me i have tried so many way to eliminate the crackle sound . the proven way is adding braided copper and solder it in both house it removed all the crackle noise. and after 4 hours listening not a single error
 
thanks to alex advice