User manual BSS FCS960

[. . . ] V2. 2 8 December 1995 Welcome Welcome to the FCS-930/960 Users Manual FCS-930 DUAL MODE GRAPHIC EQUALISER FCS-960 DUAL MODE TWO CHANNEL GRAPHIC EQUALISER The aim of this manual is to assist sound engineers, installers and consultants to fully understand the FCS-930/960; and to benefit from its maximum capability. At the same time, the information is structured under a series of broad headings for easy access. The most immediate information appears at the head of each section under the main title. As you read further into each subsequent section, more detailed, specific information is given. Should you have any comments or questions about applying the FCS930/960 series within your application, please write to us at the address in the warranty section. FCS-930 FCS-960 User's Manual This Manual is the COPYRIGHT of BSS Audio. [. . . ] The filter sets chosen are arranged in the alternate summing mode to reduce interaction, and utilise a multiple-feedback band- pass topology rather than the more generally used gyrator topology. This assures excellent high frequency fidelity by placing less demands on the associated electronics. The resulting filter shape is `constant Q' giving a constant bandwidth regardless of the amount of boost or cut selected. This produces consistent selectivity over the whole range of fader movement. The extra long 45mm faders are centre detented for accurate zero setting, as well as being centre tapped. This electrical centre tap, which is grounded, ensures each filter set is properly removed from the circuit at the faders central position. This will give you added confidence during use, as well as reassurance that, if a filter is not being used, it is absent from the signal path. Analysis has shown that the filter shape requirements depend to a large extent on the final application for the equaliser and for this reason the FCS-930/960 is provided with a MODE selector which re configures the filter sets. Normal Mode Here the Q value of the filter is set to allow groups of faders to be set in a Mode Switch Out pattern which represents fairly closely the actual amplitude response obtained. The combining effect is smooth whilst still retaining a degree of selectivity normally associated with a graphic equaliser. The constant Q design allows predictable and precise control over the whole range of fader movement. This Normal mode would be used for all sweetening type of work where boosts and cuts are combined to provide an overall smooth contouring response. Fine Mode Here the filters are reconfigured to offer a higher Q value, and hence Mode Switch In produce less adjacent filter interaction. This requirement is consistent with applications where high selectivity is required such as for correcting room resonances and where a number of notches are required to be inserted to avoid feedback. Again the filters produce a constant Q shape which allows high selectivity for small amounts of cut or boost. 13 FCS-930/960 Using the FCS-930/960 In general you would use this mode where amplitude cuts are primarily being introduced. It still however, has many applications for sweetening work as the combining response is still acceptably ripple free. High Pass Filter This third order variable filter sweeps from 20Hz to 250Hz at 18dB/oct and provides extra equalisation in applications where precise control is required on the low frequency energy within a system. This can be required for protecting loudspeakers from excessive cone excursion beyond their design limits, for optimising amplifier headroom in passively crossedover loudspeaker systems by limiting wasted power at low frequencies, or for increasing intelligibility in mainly voice based applications. Press the associated switch to select the filter, and the LED illuminates in confirmation. De selecting the function removes the filter from the signal path completely. Gain Control This control is incorporated within the filter sections offering the facility Peak LED to balance the overall sound level, after setting the required equalisation. [. . . ] However it is important that they are replaced as soon as possible to ensure continued protection. 18 Appendix Optional Balancing Transformer Fitting Optional Security Cover 8. 3 Optional Balancing Transformer Fitting The two VDRs are mounted on a small circuit board attached to the rear of the 120/240v selector switch and are specified as Philips 2322594-61312 (Max voltage 130v). Please ensure the unit is disconnected from the mains power before attempting removal. Provision is made internally to fit balancing transformers to both the electronically balanced inputs and outputs. INPUT TRANSFORMER KIT IS BSS PART No: Z-TIX1KIT-01 for the FCS-930 Z-TIX2KIT-01 for the FCS-960 OUTPUT TRANSFORMER KIT IS BSS PART No: Z-TOX1-KIT-01 for the FCS-930 Z-TOX2-KIT-01 for the FCS-960 The transformers are easily fitted onto the printed circuit board adjacent to the respective output connectors. [. . . ]