Sennheiser CH 650 S Balanced cable for Sennheiser HD 650/HD 600 headphones at Crutchfield
Amazon.com: gotor 4.4mm Balanced Replacement Cable for Sennheiser HD 650 HD 660s HD 600 HD 6XX HD 25 HD 580 HD 58x 7N Silver Plated Copper (1.2m(3.9Feet)) : Electronics
SENNHEISER 4-Pin XLR Balanced Stock Cable & ADAPTER for HD 650, HD 660 S - 10ft | eBay