Some notes on reterminating regular HD800 OEM cables to balanced XLR4:
Firstly, the main reason for doing this is savings! $379 for new-in-box Sennheiser cables is too much pain! And while there are other cables that are more affordable, they all share the same problem: the special connectors on the end are not OEM.
For this project I acquired the following parts:
Regular (Single-ended) Original OEM HD800 cable (used, head-fi marketplace)
Neutrik NC4MXX-B (amzn, B002A4GJ8Q)
3% Silver Solder (amzn, B007KN0FD2)
Assorted Heat Shrink Tubing (amzn, B00YIKEZI6)
Other items used:
30W soldering iron
helping hands
regular single-edged razor blade
small office binder clip
matches
multimeter for continuity checking
hairdryer
Cable: I kept the bulk of the cable inside a Ziplock bag with only the end I was working on extruding from the bag. This kept the cable clean and looking smart at the end of the project!
Heatshrink: I found that 6mm tubing fits great on the braided cable. I also used a smaller piece of tubing to cover the shield wire. A hairdryer on high was used to shrink the tubing.
Enamel Coating: I've had run-ins with enamel in the past so I wasn't looking forward to it. Luckily the Sennheiser wires are enameled
plus plastic insulated. After removing the major insulation with a blade, I clamped the small wires with an office binder clip. Then I used matches to burn off the exposed ends. This dealt with both the thin outer plastic insulation and enamel. I checked that the enamel was gone with a multimeter.
There are some fine threads mixed in with the Litz wire. I was able to carefully trim most of them.
Pin outs: Using the old plug and multimeter, I verified the wiring on my cable. I confirmed the wiring is as initially described in this thread (post #2, gridded chart).
1: L+ Green
2: L- White
3: R+ Red
4: R- White
The white wires are bundled with their respective color, so determining which white goes where is not an issue.
Once the wire was prepped, soldering and assembly was easy! Tape end braid and shield wires, add the Neutrik "boot", and finally 6mm heatshrink. Tin and shorten wires to proper length (18mm total, 4mm exposed). Affix plug to helping hands, fill buckets on plug with solder. Line up wire, heat bucket and shove into molten solder. Do this four times, ensuring proper wire order with pins. The pins are numbered on the back of the plug so you can't go wrong!
Join shield wires together. Put heatshrink on shield wire, feed end through shield hole, trim and solder.
Check for shorts with multimeter. Remove remaining braid tape, slide 6mm heatshrink towards connector. Heat with hairdryer. Close up connector. Do a final multimeter check. Enjoy your new balanced cable!
