3.5mm Stereo Jack - 2x 6.3mm Mono Jack | getinthemix.com
Furutech F63-S 3.5mm to 6.3mm Jack Adaptor - Analogue Seduction
3.5mm Stereo Jack Male to 6.3mm Stereo Jack Female Adapter - from LINDY UK
6.3 mm. Jack adapter (2 x 3.5 mm female - 1 x 6.3 mm male)
Adapter 6.3mm Stereo Plug to 3.5mm Stereo Female
6.35mm Plug to 3.5mm Socket (Pack of 2) 1/4 to 1/8 inch Stereo Audio Jack Adapter | Converts Audio from Amplifiers, Guitar, Piano, Drums, Speakers & Mic that use 6.35mm to 3.5mm