Be sure to add me to your favorites list Yamaha Original Service Manual for PM1800A Professional Mixing Console Mixer. Original Yamaha service manual for the Yamaha PM1800A Professional Mixing Console. This is a service manual that shows all of the differences from the PM1800, with specs, panel layout, circuit board and circuit schematic diagrams and more. Original Yamaha document, made in Japan, from 1991. In very good condition! 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. Thanks for looking! Check out my Store!