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. As opposed to most manuals, the contents can be read like a book. At the same time, the information is structured under a series of broad headings for easy access. So where possible within each section: . [. . . ] The pin connections are: Pin 1 Pin 2 Pin 3 Open circuit/no connection. Cold (-). Please take special note of the ground break on Pin 1. As with all BSS products, the convention is `screen goes forward with the signal', giving a useful ground loop break point at the input connector. The audio lead connected to the input must therefore have it's screen grounded at the signal source end. When using a fully balanced system, either Pin 2 or Pin 3 may be the HOT terminal. 12 Using the FCS-930/960 6. 0 Using the FCS-930/960 The FCS-930/960 Graphic equaliser is the result of a detailed study of sound engineers and contractors requirements plus many hours of voice and music program listening tests to carefully optimise the benefits of controlling equalisation in this ergonomically efficient and familiar manner. 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. A feature hard to realise on many other graphic equalisers. 13 FCS-930/960 Using the FCS-930/960 In general you would use this mode where amplitude cuts are primarily being introduced. [. . . ] Input Section 10k electronically balanced, +20dBu maximum input level via XLR3-31 or equivalent. Electronically balanced and floating, capable of driving +20dBu into 600 or greater via XLR3-32 or equivalent. Output Section System Performance Frequency response THD at +4dBu (faders flat) Output noise (faders flat) Channel separation Gain control range Peak indicator Bypass Filters Type Frequencies, per channel: Boost/cut range Mode High pass filter Power Voltage ±0. 25dB from 20Hz to 20kHz <0. 005% 22Hz to 22kHz <-90dBu, 22Hz to 22kHz unweighted >80dB from 22Hz to 22kHz ±10dB +18dBu Passive fail-safe bypass relay MFB Constant Q 30 off on 1/3 octave ISO centres 25Hz to 20kHz Nominal ±10dB. Note 1 Selectable normal or fine response 18dB/Oct Butterworth sweepable 20Hz to 250Hz 30VA 50-60Hz, 90-120Vac or 190-250Vac selectable externally. 2m power cord connected via IEC socket. Dimensions/Weight 482x89x227mm. [. . . ]