BSS AUDIO TM FCS-926 AND FCS-920 VARICURVE SYSTEM DUAL CHANNEL, 12 BAND, PARAMETRIC EQUALISER-ANALYSER USER'S MANUAL This Manual is the COPYRIGHT of BSS Audio. All reproduction and copying, other than for the legal owner's personal use, or disclosure of part or whole to a third party, without prior written authorisation, is in violation of the European Copyright Convention. BSS Audio. 1997.
CONTENTS SECTION TITLE PAGE 1.0 FEATURES AND FACILITIES 3 2.0 UNPACKING 4 3.0 MECHANICAL INSTALLATION 4 4.0 4.1 4.2 4.3 4.4 CONTROLS and CONNECTIONS FCS-926 Front Panel FCS-926 Rear Panel FCS-920 Front Panel FCS-920 Rear Panel 5 5 6 7 7 5.0 5.1 5.2 5.3 MAINS POWER Voltage Setting Safety Earthing AC Fusing 9 9 9 9 6.0 POWERING UP 10 7.0 7.1 7.2 7.3 AUDIO CONNECTIONS Balanced Wiring Unbalanced Wiring Ground Loop Control 11 11 11 11 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.
1.0 Features and Facilities The VaricurveTM system of audio equalisers utilises a large, high definition graphics screen and digital techniques to give an intuitive interface between the user and control of high quality analogue filters. The FCS-926 is a dual channel parametric filter equaliser offering a total of 12 individual parametric filters and a 30 band Real Time Analyser (RTA) with pink noise source.
2.0 Unpacking As part of BSS Audio's policy of quality control, this product is carefully checked before packing, to ensure flawless appearance, and that it reaches you in first class condition. After unpacking the unit, please inspect for any physical damage and retain the shipping carton and all relevant packing materials for use should the unit need returning. With the FCS-926/920 will be a small packet of spare fuses. Please keep them in a safe place.
4.0 Controls and Connections 4.1 FCS-926 Front Panel [1] ACCESS. Press this button to select the channel to be adjusted and viewed, or to select the linked stereo mode. Access to the MONO mode is made via the Utilities menu. [2] FLAT. Press to reset filter parameters to default values. Press again to undo. This toggle action is confirmed by the GRAPHICS WINDOW display, and happens 'on-line' with audio program.
[12] PARAMETER CONTROL. Rotate to incrementally adjust up or down a pre-selected parameter, press or press-and-rotate to position CURSOR [10] onto desired filter. Following selection of the sixth filter (in two channel mode) or the twelfth filter (in mono mode), the cursor jumps to VIEW mode before returning to filter one. This is confirmed by the word VIEW in the TEXT WINDOW.
Pin 1 = Open circuit/no connection.2. Pin 2 = Hot (+). 1. Pin 3 = Cold (-). 1. When using a fully balanced system, either pin 2 or pin 3 may be the HOT terminal. 2. Please take special note of the ground break on pin 1. As with all BSS products, the convention is 'ground goes forward with the signal', giving a useful ground loop break point at the input connector. 4.3 FCS-920 Front Panel Controls [1} ADDRESS WINDOW. This normally shows the current program number for the unit, eg P07.
Pin 1 = Ground/Chassis. Pin 2 = Hot (+). 1. Pin 3 = Cold (-). [22] Electronically balanced AUDIO INPUTS. Maximum input is +20dBu into 10kOhm. Inputs are fully RFI suppressed and transformer balancing is available as an internal retrofit option. The pin connections are: Pin 1 = Open circuit/no connection.2. Pin 2 = Hot (+). 1. Pin 3 = Cold (-). 1.When using a fully balanced system, either pin 2 or pin 3 may be the HOT terminal. 2. Please take special note of the ground break on pin 1.
5.0 Mains Power Before connecting your unit to its AC power source, check that the voltage selector switch located on the rear panel is correctly set. If a change is necessary, ensure that the mains fuse is also changed for one of the correct rating. The power cord attached to this unit carries the following information label. WARNING: THIS APPLIANCE MUST BE EARTHED. IMPORTANT: The wires in this mains lead are colour coded in accordance with the following code.
safety that this specification is strictly adhered to, and you will have found that spare fuses of this rating were supplied together with your unit and manual. It is very unlikely that this fuse will fail during normal use, and must be treated with some caution as to the cause, if it should do so. One of the most likely reasons will be following the incorrect setting of mains voltage switch on the rear panel.
7.0 Audio Connections The FCS-926/920 audio inputs are RFI filtered and electronically balanced, with the outputs again RFI filtered and electronically balanced and floating. They are designed to operate at any signal level up to +20dBu and will drive into loads of 600 Ohms or greater. They will be 'fuss free', regardless of your installation's complexity. 7.
8.0 Using the FCS-926 and FCS-920 The descriptions in this section apply primarily to the FCS-926. However, since the FCS-920 has essentially the same features, control of an FCS-920 is largely as described here. This subject is covered in greater detail in Section 11.0. The VaricurveTM equalisation system offers an operator interface designed for fast and intuitive control of parametric filters.
[5] The numerical value in dBs, of the amount of input gain or attenuation selected, as set through the UTILITY menu. [6] A two line text area indicating the current status and any active options. [7] A coarse dot cursor line indicating the currently selected filter and offering a dB scale at 3dB intervals. When in VIEW mode the cursor changes to a fine dot line. [8] Markers along the top of the window indicating the current centre frequency of each of the audio filters. When a filter is 'unused' i.e.
8.4.2 Adjusting the width of a filter Selecting WIDTH assigns the parameter control to adjust the selected filter's bandwidth, adjustable from a bandwidth of one-tenth octave up to 2 octaves, as indicated in the TEXT window. 8.4.3 Adjusting the Boost and Cut of a filter Selecting BOOST assigns the parameter control to the selected filter's boost or cut. The adjustment range is +/-15dB in 0.5dB increments, as indicated in the TEXT window.
either of the FREQ, WIDTH or BOOST buttons. During recall the audio filters are adjusted to the new EQ contour following the second RECALL switch selection. - see section 9.5 for adjustment of the cross-fade time. NOTE: The RECALL button has a different function in RTA mode - see section 10.7 NOTE: Access is denied to programs of the wrong access type. As the parameter control is turned, programs of the wrong mode will be skipped. In stereo mode, a complete stereo program is recalled to both channels.
8.10 Noise Optimisation. As in any multiband equaliser, large amounts of boost coupled with wide bandwidths will amplify circuit noise from preceding electronic stages. To help minimise this effect, it is desirable to position these filters at the beginning of the equalisation chain, and wide band cut filters at the end. The FCS-926 utilises a noise optimising routine which automatically reallocates the filters to give optimum noise performance.
9.0 UTILITY Menu Within the FCS-926 are a series of user adjustable and selectable utilities which further enhance it's operation and performance. These are arranged as a circular menu accessible from UTILITY. 9.1 UTILITY Menu Access Having held the RTA button for approximately 1 sec the TEXT window will change and display the Utility menu. These are arranged as a vertical sequence with the centre utility highlighted, indicating it to be the one currently selected.
9.5 Memory Crossfade Having selected utility FADE SECS, use the parameter control to adjust the cross fade time from 0.0 secs to +/- 6.0 secs in 0.1 sec increments. Positive fade time is the time taken for one EQ contour to be faded down and the replacement EQ contour faded up. Negative fade time is the time taken for one EQ contour to be merged into the new EQ contour. Cross-fading only applies to program recall. 9.
9.12 Security Lockout Having selected the utility LOCK OUT, use the parameter control to switch between OFF and ON. Selecting ON disables the parameter control and program change buttons to ensure that current settings cannot be altered and the TEXT window displays "SAFE" to confirm. Lock out does not inhibit program or parameter change via MIDI and PA-422 control interface. WARNING! LOCK OUT should not be confused with PROG LOCK (section 9.3).
10.0 Using the REAL TIME Analyser Incorporated into the FCS-926 is a 30 band RTA which can be displayed on the graphics window simultaneously with an EQ contour. A pink noise source is also included for use during room analysis. Selection of the RTA display, it's operating parameters, AUTO EQ, ROOM CURVE and ADD CURVE modes are all accessible from the RTA menu. Having selected RTA, the TEXT window will change and display the RTA options on a circular menu.
10.7 Using RTA Program Memories. When RTA menu is selected the STORE and RECALL buttons allow access to six additional program memories for the storing and recalling of complete 30-bar spectrum analysis. These are lettered A to F, and are accessible only when RTA menu is selected. 10.7.1 Storing an RTA program. Having selected RTA menu and STORE, turning the parameter control sets the program letter A to F, as indicated in the TEXT window. Program store is completed by re-selecting STORE. WARNING!.
The TEXT window changes to show program number 51, and the GRAPHICS window displays a prompt requesting a reference curve to be chosen. At this point the user can choose to equalise to either a flat response or to one of the other five preset curves available. Turn the parameter control to select a different curve. Should none of the preset reference curves be applicable, individual custom contours can be created and stored in the normal way in program 1-50.
Once conversion is complete the curve can be stored in any program memory using the usual STORE function after exiting the RTA menu. In a different venue an AUTO EQ can be run using a previous venue response as the target response. The second venue eq will be adjusted to give as near as possible the response of the previous room.
11.0 Notes on using the FCS-920 The features discussed for the FCS-926 in sections 8.0-10.0 apply largely to the FCS-920, although only via remote control since the FCS-920 has no panel controls. The 3-digit display on the front panel usually shows the selected program number e.g. P10. The device address number (MIDI channel or PA422 address), may be displayed and adjusted in the range 1-16 by pressing either of the recessed buttons to the left of the display using a blunt implement.
The display may occasionally show error messages in the form of an error number. The meanings of these are as follows. Er.2 Er.3 Er.4 MIDI data error. Cannot recall a program stored in a different access mode. MIDI buffer overflow. Any other messages would indicate an internal error- consult your dealer. NOTE: The RTA in the FCS-926 and FCS-920 has been optimised for use with a pink noise source and may not give accurate results across all frequencies with single tones.
12.0 MIDI Implementation Chart 12.1 FCS-926 MIDI Implementation Chart V1.
12.2 Parameter Numbers PARAMETER NUMBER RANGE LAW Fade Time 36 0-120 Time(S) = (n-60)/10; merge fade when negative. See note 9 Bypass 37 0-127 Bypass when n >= 40H Gain Channel 1 38 0-50 Gain(dB) = (n-26)/2; off (mute) when n=0 Gain Channel 2 39 0-50 Gain(dB) = (n-26)/2; off (mute) when n=0 Peak Fix channel 1 40 0-127 Peak Fix when n >= 40H Peak Fix channel 2 41 0-127 Peak Fix when n >= 40H Access 42 0-3 0 = 12-Band Mono; 1 = CH1; 2 = CH2; 3 = Stereo. See note 2.
Notes: 1) Non-Registered Parameter data LSB is ignored for all parameters except frequency, which uses 2 bytes. 2) The action of program change is effected by Access. If there is any danger of Access being manually changed during MIDI program change, either lock out the front panel, or transmit the required Access mode to the FCS-926 prior to each MIDI Program Change. 3) 'Reset All Controllers' has the same action as pressing the FLAT button on the front panel.
13.0 Technical Specifications INPUT SECTION 10kOhm electronically balanced and RFI filtered, +20dBu maximum input level via XLR 3-31or equivalent. Input CMRR better than 50dB 50Hz to 15kHz. 1. OUTPUT SECTION Electronically balanced and floating RFI filtered, capable of driving +20dBu into 600 Ohms or greater via XLR 3-32 or equivalent. 1. SYSTEM PERFORMANCE All filters set to 0dB boost/cut, dual channel mode.
DIMENSIONS/WEIGHT 926 Unit, net 926 Unit packed 920 Unit, net 920 Unit packed 88x483x288mm. (3.5"x19"x11.3"). 152x610x394mm. (6"x24"x15.5"). 44x483x288mm (1.75"x19"x11.3") 110x610x394mm (4.5"x24"x15.5") 5.6kg. 6.7kg. 4.2kg. 5.2kg. SAFETY: The FCS-926/920 has been tested and conforms to the safety requirements of Cenelec HD195.S6 and BS415:1990. 1 Internally fitting balancing transformers optionally available.
14.0 Appendices 14.1 Chassis/0V Link removal The FCS-926/920 has the signal 0v ground connected to the metal chassis, which in turn is connected to the safety ground. In the unlikely event that you need to remove this link, or if you need to add a small impedance to reduce earth loop currents, then proceed as follows. Since both the audio inputs and outputs are wired fully balanced we strongly recommend that you carefully re-check all audio wiring for correctness, prior to proceeding.
1: Disconnect the mains power and remove the unit's top cover. 2: On the small PCB LVS300 mounted onto the rear of the 120v/240v selector locate the purple and brown wires and reverse their positions. Locate the orange and yellow wires, and reverse their positions. 3: The wiring change is now complete and should be checked against the drawing shown below. It is not necessary to change the mains fuse values other than that required when changing the mains voltage selector. 4: Replace the top covers.
The battery can be ordered as a spare part from BSS Audio as V04-0030, or alternatively purchased from a reputable supplier as SAFT type MEMOGUARD 40LH220. Replacement Procedure. WARNING! To ensure continued retention of the memory contents, the FCS-926/920 should be left powered up during this replacement procedure. 1. Remove the FCS-926/920 top cover and locate the battery which is situated towards the front of the main printed circuit board.
15.0 Warranty Information When sold to an end user by BSS Audio or a BSS Audio Authorised Reseller, this unit is warranted by the seller to the purchaser against defects in workmanship and the materials used in its manufacture for a period of one year from the date of sale. Faults arising from misuse, unauthorised modifications or accidents are not covered under this warranty. No other warranty is expressed or implied.
