EP0364526B1 - Control console for audio signals - Google Patents

Abstract

In a digital-analog control console for audio signals, the analog channel signals are summed, and possibly processed simultaneously. The signal sum is added to a further channel signal An derived from the sum of the digital channel converted to analog form to form the analog outgoing signal. A digital signal Dn derived from the sum of the analog channel signals converted to digital form is added to the sum of the digital channel signals. The resulting digital send signal has the same modulation content as the analog outgoing signal.

Description

The invention relates to a control panel for sound signals according to the preamble of the claim. Such a control desk is known (brochures "Studer 900 Professional Control Technology PI 3/82 D / E" from Studer International AG, Regensdorf, Switzerland).

For digital broadcast signals, such as those intended for satellite radio broadcasting, it is known (brochure "New Digital Studio for the WDR" from Siemens AG) to process a large number of incoming digital channel signals by means of digital functional units. The digital channel signals either originate directly from digital audio signal sources, such as CD players, DAT recorders, or are obtained from analog audio signal sources by analog / digital conversion. Such digital control consoles are associated with multiple structural and financial expenses compared to analog control consoles and require a change of operating philosophy for the sound engineers, if one does not want to go the even more complex way of translating the operating philosophy used for analog control consoles with suitable software . Since different operating philosophies exist in the broadcasting process in each broadcaster, such software would have to be developed specifically for the broadcaster, which would drive the effort to an unacceptable size.

In contrast, the object of the invention is to provide a control desk which, with an unchanged operator philosophy, enables both an analog and a digital transmission signal to be generated without the quality of the input signals coming from digital audio signal sources being converted by digital / analog conversion and subsequent analog / To affect digital conversion and without claiming an unacceptably high technical effort.

This object is achieved according to the invention by the characterizing features of the patent claim.

A hybrid technique is used in the control desk according to the invention, the input signals originating from digital audio signal sources first being summed, and a further digital signal which corresponds to the sum of the processed analog input signals of the control desk being added to this digital sum signal. The signal resulting from this represents the digital transmission signal. Furthermore, in the analog part of the control console according to the invention, a further analog signal is added to the sum of the processed analog input signals, which is obtained from the sum of the processed digital input signals. The resulting signal represents the analog transmission signal. Both the analog and the digital transmission signal contain the identical modulation. The surface of the control desk is practically unchanged and is only replaced by level controls for those from digital audio signal sources originating input signals expanded. Alternatively, analog level controls that are no longer required can be replaced by the level controls for the digital audio signal sources. The fact that both a digital and an analog transmission signal are generated in parallel with the control desk according to the invention has the further advantage that interference in the digital part does not lead to a transmission failure. Namely, each digital audio signal source has in addition to its digital signal output also a corresponding analog signal output, which are connected for reserve purposes with analog inputs of the control desk, so that the signals originating from digital signal sources are processed in the event of an accident via the analog part of the control desk according to the invention and into the analogue Broadcast signal can be inserted. Since digital line transmitters have an additional input for an analog transmission signal for reserve reasons, the transmission on the purely digital transmission link is also ensured in the event of an accident.

The invention is explained in more detail with reference to the drawing, which shows a block diagram of the control desk according to the invention.

The control desk illustrated in the drawing has an analog part 10 illustrated on the left half of the drawing and a digital part 20 shown on the right half of the drawing. Both parts 10 and 20 are separated from one another by a broken line for better clarity Cut. The analog part 10 comprises a processing section 11, which is fed a variety of analog input signals A₁ to A _n-1 . In the processing section 11 there are level controls, filters, switching elements, control devices and the like in the usual way. At the output of the processing section 11, a processed sum signal of the analog input signals A₁ to A _{n-1 is} generated. This sum signal is fed to both an analog / digital converter 12 and a summing element 13. The output signal D _{n of} the analog / digital converter 12 is fed to the digital part 20, from which an analog signal A _{n is} fed to the second input of the summing element 13. The output signal of the summing element 13 represents the analog transmission signal, as will be explained in more detail below.

The digital part 20 has a processing section 21, which is supplied with a plurality of digital input signals D ₁ to D _n-1 . These digital audio signals usually come from digital audio signal sources, such as CD players, DAT recorders or digital signal lines (eg from the Bundespost). In a simple version, the digital processing section 21 consists only of level controls, since when signals from digital audio signal sources are fed in, no further processing, such as filtering, is required except for leveling. If necessary, the processing section 21 can of course also include digital filters, switching devices and the like.

The processing section 21 further comprises control devices, e.g. Preview button, digital level indicator and much more. As already mentioned above, the processing surface of the processing section 21 is inserted into the processing surface of the processing section 11, so that the operating philosophy of analogue control desks familiar to the sound engineer is available.

• a) die Summe der bearbeiteten Analogsignale A₁ bis A_n-1, und
• b) die Summe der bearbeiteten Digitalsignale D₁ bis D_n-1

enthalten.At the output of the processing section 21 is the sum signal of the processed input signals D₁ to D _n-1 , which is fed to a digital / analog converter 22 and a summing element 23. At the second input of the summing element 23, the output signal D _{n of} the analog / digital converter 12 of the analog part 10 is present, which means that the digitized version of the sum of the processed analog signals is supplied to the sum of the processed digital signals. As already mentioned, the output signal A _{n of} the digital / analog converter 22 is fed to the second input of the summing element 13 of the analog part 10; this means that there the analog version of the sum of the processed digital signals is supplied to the sum of the processed analog signals. The output signal of the summing element 23 represents the digital transmission signal. Comparing the transmission signals at the outputs of the summing elements 13 and 23, it is found that both signals

• a) the sum of the processed analog signals A₁ to A _n-1 , and
• b) the sum of the processed digital signals D₁ to D _n-1

contain.

With the help of the control desk according to the invention, a very cost-effective, quick and flexible entry into digital radio on the studio side is made possible without restricting the quality. The need to purchase a large, expensive control desk using purely digital technology is eliminated, as is the need to retrain the sound engineers.

Claims (1)

1. Control panel for audio signals, wherein

   - a plurality of analog channel signals A₁ to A_n-1 are, if required, added in an analog adding unit (11) under simultaneous processing, and

   - a further channel signal A_n is added to the sum of the analog channel signals A₁ to A_n-1 in a further analog adding unit (13), resulting in an analog transmission signal,

   characterized in that

   - the sum of the analog channel signals A₁ to A_n-1 is transformed into a digital signal D_n in an analog digital converter (12);

   - a plurality of digital channel signals D₁ to D_n-1 are, if required, added under simultaneous processing in a digital adding unit (21);

   - the sum of the digital channel signals D₁ to D_n-1 are transformed into an analog signal in a digital analog converter (22), whereby the further channel signal A_n is formed, and

   - the digital signal D_n, obtained by the transformation of the sum of the analog channel signals A₁ to A_n-1, is added to the sum of the digital channel signals D₁ to D_n-1 in a further digital adding unit (23), resulting in a digital transmission signal having the same modulation content as the analog transmission signal.

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