Does it matter the wire gauge used in interconnects?


I am thinking of trying my hand on building some DIY interconnects. It will be balanced (XLR) and 10 feet long. I have seen interconnects made with thin 30 gauge wire, is there an advantage using super thin gauge wire?
I was thinking of using 20 gauge but is that too thick for interconnects?

ozzy
128x128ozzy
@ozzy  AWG 20 sounds OK.  My Acoustic Zen Absolute ICs have gauge 20 wires.  I assume you're going to twist wires.  XLR are usually twisted.  Twisting exposes both wires evenly to external electric and magnetic fields reducing interference pickup (very effective).  Twisting reduces inductance (not important here) and increases capacitance.  Perhaps light twist?  Twisting is effective when twist pitch is way below wavelength of offending signals.  Let's assume 1" twist pitch is way below 0.3m wavelength of 1GHz signal.  At these frequencies shield works great (skin effect).  I would use insulation with low dielectric constant to lower capacitance between wires (Teflon?).  Perhaps oversized overall tube with low dielectric constant to reduce capacitance to shield?  (my ICs have foam Teflon insulation in oversized tubes).  

With thicker wires you risk skin effect, that starts at gauge 18 in copper at 20kHz, but speakers are usually inductive in character at these frequencies, meaning that impedance gets way higher reducing skin effect (If it is audible to start with).  Good luck and let us know.
Unless you are driving properly terminated XLR (110 ohms), odds are you are dealing with source resistances of 600-2K ohms, and load resistances of 10K - 100K. Fairly small wires will work well at the typical lengths used. But then again large wires will work too.


Skin effect is a non issue. A larger gauge wires has more surface area than a smaller gauge wire, so even though it experiences more skin effect, its overall conductance is still lower.

Because of high load impedance, inductance in the cables is a non issue unless you do something ridiculous like the helix construction where you can actually make an inductor large enough impact signal transmission. More concerning is high capacitance due to the high source impedance. Whether exotic insulator really make a difference is up for debate. It sounds good on a marketing sheet.

Twisted pair construction and overall braid shielding will rarely steer you wrong, though overall braid does increase capacitance.


@ozzy  I should've explain better in my last paragraph, that gauge 18 would be even fine even for the speaker cable, while for ICs it doesn't make any difference.  Gauge of IC wire should be thick enough for easy handling.  That's perhaps why Acoustic Zen selected AWG 20.  Capacitance is directly proportional to dielectric constant.  Selecting Teflon (k=2) instead of PVC (k=4) lowers capacitance by factor of two.  Using oversized tubes reduces it even more.
kijanki, audio2design,
You guys really know your stuff. Thank you for that very helpful information.
So for now, the plan is to use 20 gauge soft .9999 solid silver wire with oversized PTFE tubing and braiding the cable slightly.

I was thinking of using Xhadow XLR connectors but they don't seem to be available anymore. When I look at the XLR connectors that are available they seem to use a lot of metal in there design, which to me seems like it could affect the sound.
Is there any XLR connectors that use minimal metal like some of the RCA connectors I have seen?

ozzy
ozzy, are you speaking of the outer case? You want something like carbon fiber or something. Darker? No shiny outer case?

They make them with good internals. Just about everything you can think of.. Stick with something that stays clean, inside. I’ve seen silver, inside, kinda spendy, rhodium, nickel plated everything (:-)) Carbon fiber outside.

I’ll look https://www.aliexpress.com/item/32972013684.html

The wire composition, dielectric and cover more than anything with XLR, the size to big is to big. Weight for one and I think if you go to big it does loose a certain twinkle. I know it takes forever to break some of the pure silver in. Not that is sounds bad, but it change for 2-300 hours..

Regards.