Tying in shield for headphone cables (esp. balanced situations)?
post-7666521
Thread Starter
Post #1 of 4

cyberspyder

Caution! Incomplete trades.
Joined
Mar 2, 2007
Messages
1,993
Reaction score
23
Joined
Mar 2, 2007
Posts
1,993
Likes
23
Important or no? I'm used to making guitar and mic cables and we always use the shield in a XLR connector, is there any benefit for headphones? Because for you typical 4 pin XLR balanced plug, there is no option for tying in the shield, and if you wanted to use the shield for a 2 x 3 pin XLR termination, you'd need at minimum a 6 conductor cable (4 signal and two shields), or two balanced pair cables twisted together. Am I correct?

For making TRS extension/IC cables I've always used the shield as ground and twisted the wires into two pairs for the left and right channels respectively. Is there any reason why I should not do this?

Cheers, Brendan
 
     Share This Post       
post-7666544
Post #2 of 4

nikongod

DIY-ku
Joined
Jan 24, 2005
Messages
8,882
Reaction score
120
Joined
Jan 24, 2005
Posts
8,882
Likes
120
There are reasons to do it either way with regards to sheilded output cables. 
 
In a nutshell: Shielding cables reduces the problem of noise entering the amp through the outputs BUT increases the capacitance of the cable which may not play nice with all amps. 
 
Its kind of a personal choice. 
 
For the second bit, use one wire for signal, one for ground and then float or ground the shield depending what you decide to do for that. Using shield as signal ground, and 2 wires for each channel causes extra cross-talk. 
 
     Share This Post       
post-7666553
Post #3 of 4

cyberspyder

Caution! Incomplete trades.
Joined
Mar 2, 2007
Messages
1,993
Reaction score
23
Joined
Mar 2, 2007
Posts
1,993
Likes
23
Ah I forgot to mention I was using starquad as an example for the second portion.

I hear you on the capacitance problem, if there was any sort of standard everyone could adhere to that'd be great. Like this:

http://tamaudio.com/store/index.php?route=product/product&path=37_48&product_id=99

Why on earth would you use dual TRS plugs on a balanced cable, and not TR?

Thanks!
 
     Share This Post       
post-7666732
Post #4 of 4

nikongod

DIY-ku
Joined
Jan 24, 2005
Messages
8,882
Reaction score
120
Joined
Jan 24, 2005
Posts
8,882
Likes
120
TR is one of the standards for SE signal transmission and will short a balanced amp to ground, which is OK if the amp (or more commonly source) is designed for it. TRS is for balanced. I have no idea why anyone would put dual pugs*, regardless of their type, on a headphone cable when a single 4-pinXLR and a couple adapters covers you for any dynamic amplifier. 
 
*its an outdated standard, just poking fun. 
 
     Share This Post       

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top