User manual MERIDIAN AUDIO 558

[. . . ] 16 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Service and guarantee . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 problems. 1 Setting up the multi channel power amplifier 5 Troubleshooting 15 iii Preface iv Preface Introduction The 558 Multi Channel Power Amplifier provides five discrete power amplifiers in a single enclosure, and is ideal for multi-channel surround systems. [. . . ] Do not attempt to lift it without assistance. r Near heat sources, eg a radiator. r Stacked with any other audio products, as the heat it generates may damage the other products. Before connecting power Do not restrict airflow through the top and bottom vents. Before you begin installation you should ensure that your multi channel power amplifier is set to the correct voltage for your local AC supply. If it is not, do not try to install the unit, and contact your dealer. Do not make connections, or insert or remove plugs, while the unit is connected to the supply and switched on, as the transients generated could damage the loudspeakers. 6 Connecting the multi channel power amplifier Back panel Select balanced/ unbalanced input Select bridged mode for channels 4/5 Balanced inputs Unbalanced inputs Select bridged mode for channels 1/2 ON Power and fuse OFF INPUT SELECTOR BALANCED INPUT SELECTOR BALANCED ON BRIDGED MODE INPUT SELECTOR BALANCED INPUT SELECTOR BALANCED ON BRIDGED MODE INPUT SELECTOR BALANCED Setting up the multi channel power amplifier UNBALANCED UNBALANCED OFF UNBALANCED UNBALANCED OFF UNBALANCED BALANCED BRIDGED MODE INPUT CHANNELS 4/5 UNBALANCED BALANCED BALANCED BALANCED BALANCED BRIDGED MODE INPUT CHANNELS 1/2 TRIGGER INPUT UNBALANCED UNBALANCED UNBALANCED UNBALANCED ­ ­ LINK FOR BRIDGED OUTPUT MODE ­ ­ ­ ­ ­ ­ LINK FOR BRIDGED OUTPUT MODE ­ ­ + + CHANNEL 5 + + ­ CHANNEL 4 + + + + ­ + + + + BRIDGED OUTPUT MODE CHANNEL 3 CHANNEL 2 BRIDGED OUTPUT MODE CHANNEL 1 Outputs channel 5 Outputs channel 4 Outputs channel 3 Outputs channel 2 Outputs channel 1 7 Outputs The following table gives details of the output connections: Use this output CHANNEL 1 to Setting up the multi channel power amplifier connections to the bass/mid and tweeter units this allows the units to be connected independently to the multi channel power amplifier, for optimum sound quality. Alternatively, for loudspeakers providing a single pair of inputs, either of the output terminals can be used. To connect to this Loudspeakers of 4 to 15, using either plug or bare wire connections. CHANNEL 5 Inputs The following two alternative audio inputs are provided for each channel: Use this input UNBALANCED To connect to this A preamplifier, using phono connectors and high-quality screened cable. BALANCED A balanced analogue output, using XLR connectors: 1 (Green) = GND 2 (Red) = +ve 3 (Black) = -ve Select the appropriate input using the INPUT SELECTOR for each channel. The recommended assignment of channels, to make best use of the capacity of each power supply, is as follows: Channel CHANNEL 1 CHANNEL 2 CHANNEL 3 CHANNEL 4 CHANNEL 5 Assignment Main left Main right Centre Rear left Rear right Alternatively, channels 1/2 and 4/5 can be used in bridged output mode; see To wire to A500 Loudspeakers in bridged mode, page 12. Each channel of the 558 Multi Channel Power Amplifier provides twin outputs for bi-wiring. On speakers that provide separate 8 Standby Once set up, the multi channel power amplifier can be left in standby as it consumes negligible power in this mode. To bring the amplifier out of standby press the button on the front panel. Alternatively, the 558 can be brought out of standby automatically using the TRIGGER INPUT; see below. If you are not going to use the multi channel power amplifier for a period of several days you should switch the unit completely off, at the back panel, and disconnect it from the AC power supply. Setting up the multi channel power amplifier Trigger input The TRIGGER INPUT can be used to bring the multi channel power amplifier out of standby by applying a signal from a control unit. The trigger input should be an AC or DC signal of between 5 and 30V. Suitable trigger signals are provided by the Meridian 561, 562, 568, 800, or 861. 9 Connecting a source To connect to an analogue preamplifier (eg Meridian 501/501V) 558 Multi Channel Power Amplifier 501/501V Control Unit OUTPUT OFF To connect to a 568 Digital Surround Processor 558 Multi Channel Power Amplifier 568 Digital Surround Processor REAR-L RIGHT C LEFT REAR-R OFF OFF Setting up the multi channel power amplifier q Switch the BRIDGED MODE switch for channels 1/2 to the OFF position. q Connect the sockets marked UNBALANCED on the back panel of the multi channel power amplifier to the outputs from your preamplifier. q Switch the INPUT SELECTOR switches for the corresponding channels to the UNBALANCED position. You should either use a twin-screened audio cable, or a pair of single-screened audio cables. These cables can have a considerable effect on the quality of the sound, and you are advised to seek your dealer's advice on the best type of cables for your system. q Switch the two BRIDGED MODE switches to the OFF position. q Connect the LEFT, RIGHT, and CENTRE balanced outputs from the 568 to the CHANNEL 1, 2, and 3 BALANCED inputs on the 558. q Switch the INPUT SELECTOR switches for CHANNEL 1, 2, and 3 to BALANCED. q Connect the REAR-L and REAR-R phono outputs from the 568 to the CHANNEL 4 and 5 UNBALANCED inputs on the 558. q Switch the BRIDGED MODE switches to the OFF position. [. . . ] In case of difficulty within the UK or USA please contact the appropriate sales and service address shown on page ii. Outside the UK, local warranty liability is restricted to equipment In case of difficulty outside the UK or USA, contact the importing agent for the territory. A list of Meridian agents abroad is available from Meridian Audio. Troubleshooting Guarantee The 558 Multi Channel Power Amplifier is guaranteed against defects in material and workmanship for two years from the date of purchase. has been subject to misuse, accident, or negligence, or has been tampered with or modified in any way without the written authorisation of Meridian Audio Limited. Attempted servicing by unauthorised people may also invalidate this guarantee. [. . . ]