Schematic in PDF form for a BCi 450 W amplifier, marked 2R and dated 2013 according to the file name. The name gives no further detail about the circuit topology or board revision, so treat the 2R token as a variant label rather than a confirmed specification. Audio technicians use drawings like this to trace the supply rails, bias network and output stage, check transistor pinouts and compare component values against a damaged board. Any PDF reader opens it; compare the printed board layout with the drawing before replacing parts.
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.