This invention relates to a modular software definable pre-amplifier.
Pre-amplifiers are fixed units that implement signal conditioning for several input formats. The type and level of signal conditioning is limited and tends to be performed in the analogue domain. This tends to introduce unwanted affects in terms of noise and signal distortion. Manipulating signals in the digital domain provides improved performance. For example, digital filters have the following advantages over their analogue counterparts;                they do not drift,        linear phase characteristics are possible,        they can handle low frequency signals,        the frequency response characteristics can be made to approximate closely to the ideal,        the accuracy of the filter may be controlled by selecting the appropriate word length.        
Many of today's music formats are produced and stored in the digital domain. There is also an increasing array of media types and device to play them; compact disc players, Digital Versatile Disc (DVD), MP3 players, Mini-Disc player, Digital Audio Tape (DAT). There are currently several data formats MPEG 2, MP3 and new formats are being introduced or planned, such as MPEG 4 audio. This makes it difficult for consumers to keep up to date with new technology. New standards are constantly being developed e.g. MPEG4 and MP3, which means equipment can quickly become obsolete requiring the consumer to purchase new units if a new media type is adopted. Also the interfaces between units can change so interconnection between legacy equipment means that the units are incompatible. With the introduction of new media formats new systems require interface upgrades, which requires changing more than the interfaces, usually a whole system element needs to be replaced and new hardware and software installed. In fact, interfacing between system elements can be one of the most complex problems to overcome as many new interfaces rely on software protocols to implement their functionality. For example Universal Serial Bus (USB), Firewire (1394 standard) and UTOPIA Level 2 interfaces.
Being able to swap between the different formats without having to substitute whole equipment units would be a great advantage and cheaper for the consumer.
Interconnection between the various equipment boxes requires many cables and tends to be unwieldy. It also means that a pre-amplifier unit is dedicated to the system to which it is attached. Other remote devices cannot access the facilities provided by the pre-amplifier apparatus.