M61511FP Audio Signal Processor

The M61511FP is a function select IC and Audio Signal Processor (ASP) manufactured by the Mitsubishi Corporation of Japan. It is located on the PCB side of the main board and provides digitally switched input selectors, together with independent volume control presets, forming the main audio selection block for all inputs to this amplifier. This ASP also contains the tone, bass boost, and attenuation blocks for stereo channels.

All the RCA input sockets, at the back of the amplifier, feed their analogue signals directly into this chip via decoupling capacitors; hence, occasionally it is possible to damage this chip by feeding large signals at the input. If one of the input sockets stops working, or if all the inputs to the amplifier stop working, then this IC is the one to check. Ideally, one should check to see if it is operational. Sometimes the input selectors remain stuck due to internal damage. It is a big job to replace this QFP style chip, but not an impossible task.

This Article Continues...