[robrob]

I made what turned out to be a pretty nice hybrid balanced cable for my HiFiMan HE-500 headphones using very high quality Canare L-4E6S Star Quad cable. The details of the build are here: http://robrobinette.com/HeadphoneMods.htm#HE-500 I say "hybrid" because the cable's star quad wrap and braided shield provide RFI protection to the earcup split, then the conductors are braided in a 4-wire round braid for 3 inches, then the conductor pairs are twisted to the earcup SMC connectors.
 

 

 

 

[nk77]

Nice work mate. I understand the Canare quad is popular but any reason for using it over the Mogami or Gothams? I know that for short distances capacitance is a non-issue but thought I might ask anyway....

 

[nk77]

Oh BTW please build me one also 

 
(Is that a Model M keyboard?)

 

[robrob]

The Gotham mini quad is 26 AWG and the Canare is a beefy 21 plus I had the Canare Star Quad on hand. I have no experience with the Mogami.
 
The computer keyboard is just an old IBM unit.

 

[nk77]

Great idea having balanced 4 pin xlr as a termination - then add adapters to whatever amp you wish if you have multiple amps or want to switch later on...xlr>1/4" or xlr>bananas. Nice read.

 

[nk77]

What is the characteristic impedance of these quads?

 

[Speedskater]

Quote:

What is the characteristic impedance of these quads?

At what frequency?
 
@ 20Hz maybe almost a meg-Ohm
@ 20kHz maybe a couple of hundred Ohms
@ 1MHz my guess would be in the 40 to 80 Ohm range.
 
Why do you ask?

 

[nk77]

Wondering about reflections but it is probably not important. 
 
EDIT: CI is not dependant on length right?

 

[robrob]

The Canare Star Quad cable would be a good choice if you wanted to remove all the coax cover and just use the 4 conductors in a braid--although it would be a pain to remove 10 feet of cover and shield. The 4 wires have a "twist memory" that makes them very easy to twist into pairs for the run to the earcups. Be sure and twist the wire counter-clockwise (when looking down at the wire). I initially twisted my blue wire clockwise and they wouldn't twist nice and tight like the white wires. The whites were twisted correctly and the blues went the opposite direction.

 

[Speedskater]

A circuit's  'Radio Frequency Characteristic Impedance' is not dependent on length only in a correctly designed transmission line system.
This only matters when the cable is a good fraction of a wave-length long.  Got any mile long audio cables?
Poorly  designed systems will have reflections, but at radio frequencies.

 

[nk77]

I see... So not at standard audio frequencies. Of course material and diameter of the cable does come into play as well? 
 
Just getting into the DIY side of audio finally;getting sick of waiting for others to reply and quotes and paying more than what the product is worth. Although sometimes I can justify the price difference...well to my decreasing bank funds anyway.. Haha. 
 
Don't get me wrong all my experiences with guys in the audio business  have been great but I want to to do this for myself. So it's encouraging to see these sorts of threads.