Bottom-side PCB layout for the R2 amplifier design rated 500 watts at 4 ohms, stored as a 138 KB PDF. This layer carries the copper tracks, which makes it useful for tracing supply rails, ground returns and feedback paths, and for spotting burnt or lifted traces on a damaged board. It is meant to be used together with the top component overlay. Print at 100 percent scale without fit-to-page scaling if making a toner-transfer board, and confirm pad spacing against real transistors and capacitors first.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @pdf_servicemanual. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.