Active Mic Splitter Operation Manual August ‘04
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CONTENTS 1.0 OVERVIEW 4 2.0 TECHNICAL SPECIFICATION 5 3.0 3.1 3.2 3.3 3.4 3.5 INSTALLATION Inspection and unpacking Operating Environment CE Standard and LVD Power Requirement Warranty 6-7 4.0 4.1 4.2 4.3 4.4 DESCRIPTION OF CONTROLS Phantom +48V indicator Pad Listen 8 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 EXTERNAL CONNECTIONS Input Link Output A, B, C and D Power In Power Out Signal Levels Multiway Connector Option Input-Output Options Grounding Output D 9-14 6.0 6.1 6.2 6.
1.0 OVERVIEW PRODUCT OVERVIEW Main Features: • • • • • • • 12 Channel 1 into 4 (12 into 48) Active Mic Splitter Unique Input & Output configuration options Unity Gain signal path for ease of set-up Drives long cable runs without level loss Compact design e.g.
2.0 2.1 TECHNICAL SPECIFICATIONS MS1224 ACTIVE MIC SPLITTER ELECTRICAL Frequency Response: Equivalent Input Noise: THD + Noise: 20Hz to 20kHz, +0, -0.5dB -122dBu, 20Hz to 20kHz < 0.01% Input Impedance: Maximum Input Level: 2k 0dBu (+20dBU with Pad) Output Impedance: Load Impedance: Gain: < 15R > 150R 0dB (-20dB with Pad) Bargraph Calibration: -60dB to +20dB Power Requirement: +17V, -17V DC and +48V PHYSICAL 2.
3.0 INSTALLATION 3.1 INSPECTION AND UNPACKING The MS1224 Active Mic Splitter and Power Supply units have been carefully packed at our factory in a carton designed to withstand handling in transit. Should the unit appear to have been damaged in transit, notify your dealer immediately and do not discard any of the packing. The carton should contain • • • • 3.
discretion replace, any defective item without charge for labour or parts. To receive service under this warranty it is necessary to return the unit to an LA Audio authorised service centre or to the factory with a dated receipt as proof of purchase. After repair the unit will be returned to you free of charge. Limitations: This warranty does not cover damage resulting from accident or misuse. The warranty is void unless repairs are carried out by an authorised service centre.
4.0 DESCRIPTION OF CONTROLS 4.1 PHANTOM switch Individual Phantom Power switches per channel switch +48V on to the Input connector. Please note: To prevent the chance of damage to any external pieces of equipment, do not use the +48V power option with unbalanced input sources i.e. those where pins 1&3 or 1&2 are connected together. To avoid loud and potentially damaging electrical noise always turn down all associated amplifiers and always connect microphones before switching phantom power on. 4.
5.0 EXTERNAL CONNECTIONS Option A - Front view 5.1 Option A - Rear view INPUT The Microphone input is electronically balanced via a XLR-F connector with pin 2 wired hot (signal +). Input impedance is 2k and is suitable for low impedance dynamic or capacitor microphones. Although the inputs are designed for balanced operation either pin 2 or pin 3 can be connected via the external cable to pin 1 for unbalanced operation.
Pin 1 on OUTPUT D is normally supplied with pin 1 ground lifted. Refer to Section 5.9 for details of how to ground OUTPUT D. 5.4 POWER IN A 36 way Centronics style connector carries all DC power, signal monitoring and grounding connections. Normally connected to the MS1224 Power Supply Unit - see Section 6.0. 5.5 POWER OUT A duplicate power connector to allow easy daisy chaining of multiple MS1224 Active Mic Splitters to a common power supply. 5.
The following diagram shows two wiring examples when using 56 way EDAC connectors. 5.8 INPUT-LINK-OUTPUT OPTIONS A, B, C and D A unique feature of the MS1224 is the ability to re-configure the Input-Output panels - Option A: INPUT, LINK and OUTPUT D are on the front of unit and OUTPUT A, B and C are on the rear of unit Option B: The reverse of Option A i.e. INPUT, LINK and OUT D are on rear of unit and OUT A, B, C are on front of unit.
Coverting from option A to Option B: • Remove the top cover – 8 x M3 countersunk screws. • Remove chassis – 8 x Hex Button screws (2mm AF Allen Key required) and 4 x M3 x 6 countersunk screws on base. • Disconnect the 10 way ribbon cable connector from each of the channel boards (J4). • Disconnect the 4 way power cable from the rear of the Centronics connector panel. • Disconnect 20 way ribbon cable from Centronics panel. • Remove the Switch panel assembly – 8 x M3 Pan screws.
Option C - front view • Option C - rear view Referring to the Channel board diagram – • Remove the 3 x jumper links fitted to LK1 and LK2 • Remove the 3 x jumper links fitted to LK3 and LK4 Channel board link positions for Option C and D • Fit a 3 way, 16cm cable assembly (Order No. 2010205) between P3 & P6 • Fit a 3 way, 16cm cable assembly (Order No. 2010205) between P2 & P7 • Turn chassis through 180° (only required for Option D) i.e.
5.9 • Re-connect 4 way power cable to rear of Switch panel. • Re-fit cover – 8 x M3 countersunk screws. GROUNDING OUTPUT D Referring to the above diagram the shorting link on P11 can be used to ground pin 1 on OUT D. Please note: Ex-works default is with OUTPUT D ground lifted.
6.0 POWER SUPPLY UNIT The MS1224 Power Supply unit houses the INPUT and OUTPUT ground lift switches, DC power supplies and monitoring section. Each Power Supply can power up to four MS1224 Mic Splitter racks i.e. 48 channels. 6.1 DESCRIPTION OF FRONT PANEL INPUTS Ground lift switch and fuse, common to all INPUTs. OUTPUT A, B and C Ground lift switches and fuses for OUTPUT A, B and C respectively. Please note: Pin 1 on OUTPUT D is normally supplied with ground lifted.
MONITOR METER A 10 segment bargraph which displays the level of the signal on the monitor bus. The display has a very wide input range, -60dBu to +20dBu, so can be used to give an indication of signal presence as well as signal level. LEVEL Controls the volume of the monitor signal to the PHONES output socket Please note: The channel monitoring circuit on the MS1224 incorporates a dynamics enhancement and protection system.
MAINS Standard IEC type detachable mains cable connector. FUSE Standard 20mm fuse connected in series with the incoming mains supply - see Section 3.5. 6.3 POWER REQUIREMENTS The MS1224 Power Supply is factory configured for either 230V 50Hz ac or 115V 60Hz ac mains operation.
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