Tone control circuit intended for a 2.1 channel audio system, in a 159 KB PDF. It shows the bass and treble adjustment network that sits between the source or preamp and the power amplifier stages. Hobbyists use it to build or repair the tone board, check potentiometer values and trace signal routing. Verify the supply voltage the stage expects and make sure its output level matches the input sensitivity of the amplifier it feeds.
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.
Any PDF readerSumatraPDFFirefox / ChromeFlexBV (links PDF to boardview)