Be sure to add me to your favorites list Yamaha DG100-212A Guitar Amplifier Service Manual. This is a printed paper hardcopy copy of a Service manual for the Yamaha DG100-212A guitar amp. This is an abbreviated service manual, as it does not include the information for the DG100-212 model, and covers only the differences in this "A" model. You will need the DG100-212 service manual in addition to this, in order to fully work on your amp. It does have a few pages of some helpful info though, as seen listed below. This one is extremely lightly used and includes: Cover sheet Specifications / full specs on both the DG100-212 and DG100-212A When updating the Version / Rewriting ROM Data with MDF3 Parts list for Pre-Main Unit / Parts list of electrical parts 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!