Balanced wiring for Sennhesier 800 S

@dbphd I would highly recommend you purchase quality aftermarket cables instead of building your own. There should be a number to choose from, like Arctic Cables, Norne Audio, Moon Audio and others. The headphone side connectors are a royal pain to assemble since there are multiple pins and they are small and very close together. 

I and several others here have bought LavriCables headphone cables and have been very impressed with their performance, build quality, and value.  Here are the cables they make for your ‘phones…

https://www.lavricables.com/cables/master-silver-sennheiser-hd800-upgrade-cable/
 

https://www.lavricables.com/cables/grand-silver-sennheiser-hd800-hd800s-hd820-upgrade-cable/

Best of luck. 

I've used both Lavri and Moon Audio Black Dragon balanced headphone cables and they sound fine.... 

The Ayre QX-5 uses separate left and right inputs for balanced, so I need a cable with two 1/4" connectors to the QX-5 and two connectors to the Sennheiser 800S, essentially separate left and right cables wrapped together and split out only at the ends.  Where might I find such a cable? 

You can try LavriCables as I think I’ve read they can do custom cables so worth a shot just to see. 

LavriCables can do it.  I made a mistake about the balanced inputs to the QX-5.  They're 3.5 mm, not 1/4".  So I need two cables with male 3.5 mm plugs at one end and Sennheiser 800S connectors at the other.  The cables should be wrapped together except at the ends.  

I may try the unbalanced cable that comes with the 800S before ordering balanced cables.  Ayre offers 3.5 mm and 1/4" unbalanced inputs.  

I have balanced cables with my Sens......I think someone years ago recommended Cardas.......still have them