Hi anjo,
Here’s a basic dual battery +/-9VDC supply for GK3. I recommend adding two LEDs for +/- voltage status and as a precaution, two protect 1N4148 diodes - forward and reverse diodes. Two PP3 9V battery will only last about nine hours with GK3 use, or two heavy recording sessions. Finally, GK3 battery power needs care, as some op-amps can be be damaged with one voltage-rail dipping below op-amp minimum operating voltage. Best go for a v-guitar power supply instead, or use a dual-battery setup with great care.
Two GK battery adapters: Both offer the same specifications, though the boxed unit is easily modified and does not need diode polarity protection.
