Be sure to add me to your favorites list Yamaha Service Notes Bulletin to Repair G10C Synth Guitar Module A/D Converter These are 3 pages of a Yamaha service notes bulletin, specifically for the updating of the ROM and repairing the miss-operation of the on board A/D converter of the G10C module which is used with the G10 guitar synthesizer. These sheets are a very good reproduction of the original sheets, printed out on standard paper and very lightly used. Great for the G10 user if you have this particular issue with your G10C. This is a manual or document, this is NOT a piece of equipment or instrument. If you have any questions, I'm always happy to answer them. Thank you so much for looking! Check out my Store!