Yamaha - Adapter Header Electrical Connector 90890-01328-00. Overview. This adapter header is one of those small but critical pieces you don't think about until something won't connect the way it should. It's designed to bridge Yamaha electrical components cleanly, keeping your rigging solid and dependable. Whether you're troubleshooting or setting up new electronics, having the correct adapter avoids guesswork and messy wiring. It's a straightforward part, but it plays a big role in keeping you