Originally Posted by Claritas
E-mail Dale Thorn: he might know.
Thanks for the referral.
Looking at the top of the drivers, I believe the "block" on the left is Negative. I've re-cabled the vintage 'phones with what I think is Canare Quad wire. It looks the same color as the stock cable and almost the same diameter. I salvaged the stock cable splitter housing and cup entry - strain relief caps. I listened to it and it sounds "right;" much better than in Mono mode. Testing with DMM for Resistance between all TRS sections and both driver terminals
appears to read correctly for both channels.
This weekend I will test with REW impulse response and my measurement kit. Hopefully, both channel impulse responses will spike UP.
I am SO glad I did not try to remove the drivers from the cups! Doing so would have risked breaking the tiny driver wires.
Beyer DT48S 200 ohm disassembled. Simply remove the screw on the back of the cups. The rear plate lifts right off.
Do NOT try to remove the drivers from the cups or you risk damaging the driver wires - the location is shown in one of the pictures, below. Do NOT stick a tool or anything else down inside the hole between the two driver terminals. The wires are attached underneath the terminals and routed through the hole to the drivers. These wires are enamel insulated and smaller than anything I've seen...much smaller than AGW 36.
DMM readings show 175 ohms for both channels.
I cut off the black wire on the blue/left side and the clear wire on the red/right side. On the 6.3 mm TRS plug side, I joined the clear and black wires for common ground. I re-soldered the stock cable wire tabs onto the new wires. The tabs attach to the empty screw sockets on each driver using tiny brass screws. Using tabs instead of soldering directly to the terminals avoids the risk of damaging the tiny driver wires.
New 6.3 mm TRS plug with heat shrink.
Salvaged Stock Cable Splitter...Just needs screws and glue.
Salvaged stock cable splitter housing
Re-cabled and stock splitter riveted together.
New cables with stock strain relief caps.
Needs a little clean up and rust removal.
New pads would help the sound that's missing bass below 150 Hz.
Most of the rust and grime cleaned off
Edited by bluemonkeyflyer - 5/3/14 at 3:20pm