Specifications

CA10 Course Notes
Sharp Electronics (UK) Limited
CE Technical Support GroupPage 36
Audio Processing
In the current range of models fitted with the CA10 chassis there is the possibility of three different sound
output types. These are mono, stereo ( NICAM or AV ) and SRS ( Sound Retrieval System ). The
schematic diagram below shows the circuit arrangement for a typical SRS model.
Figure 35 : Audio Stage Circuit Diagram
As can be seen from the diagram shown above, all the audio signal processing is undertaken by IC305
( MSP3410D ). The MSP3410D is a Multi standards Sound Processor ( MAP ) that is capable of decoding
and processing the majority of sound systems found around the world, depending on the instructions it
receives on the I C bus. In this receiver it is set up for FM mono sound at 6MHz and NICAM stereo sound
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on 6.522MHz. Because of the programming of the memory this can not be changed, i.e. the receiver can
not be modified for use in another country. It is possible to control a number of analogue audio inputs,
this receiver is equipped with two SCART sockets ( AV and RGB ) on the rear and an AV socket on the
front. These inputs can be switched to four outputs - rear AV and RGB sockets, headphones and main
sound amplifier.
Control of IC305 is achieved over the I C bus 1 line. However control can only take place once the IC has
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been reset. Please refer to the Resets and oscillators section of these notes for more details on how
IC305 is reset.