Amazon.com: 9V AC Adapter Charger for Casio WK-110 WK-200 WK-210 WK-3700 MA-150 MA-170 Keyboard Power Supply : Musical Instruments
This is great! Casio WK-3700 synth keyboard with DSP and ZPI processor - YouTube
Casio WK-3800 76 Key Digital Keyboard Workstation - Newegg.com
T-Power AC Adapter for Casio Keyboard 12VDC WK-1630 ad-12ul WK-3700 Piano PRIVIA PX-100 PX-110 PX-320 PX-400R PX-500L WK3800 WK-3700 Portal Electronic Piano Keyboard ONLY Power Charger Supply