User manual MERIDIAN AUDIO 557

[. . . ] 16 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 1 Setting up the Stereo Power Amplifier 7 iii Preface iv Preface Introduction In choosing the 557 Stereo Power Amplifier you have acquired a component that combines major advances in audio and engineering design. The 557 Stereo Power Amplifier uses a unique feedback topology and precision local error correction system. It includes a massive twin wound toroidal transformer, and the unit has full thermal, load, and DC protection. The 557 Stereo Power Amplifier can also be operated in bridge mode, for over three times the power output to a single loudspeaker. This guide is designed to enable you to obtain the best possible results from the unit in conjunction with the other units in your system. The Meridian 500 Series The Meridian 500 Series is a unique system of digital, analogue, and video components designed to meet the demand for absolute quality, ease of use, and lasting value. The flexibility of the Meridian 500 Series is such that you can assemble a system as simple or as complex as you need, perfectly suited to your musical and environmental requirements, and with the ability to add to it or change it at a later date should your requirements change. [. . . ] Dimensions 176mm x 400mm x 320mm (6. 9" x 15. 7" x 12. 6"). Weight Introduction Available accessories The following accessories are available from your dealer: r Power cord Europe. 30VA quiescent, 1200VA max. Consumption Meridian Audio reserves the right to amend product specifications at any time. 6 Setting up the Stereo Power Amplifier This chapter explains how to install the Stereo Power Amplifier. It describes what you should find when you unpack the Stereo Power Amplifier, how you should connect it to your other audio equipment, and the siting constraints. You should not make any connections to the Stereo Power Amplifier or to any other component in your system whilst the AC power supply is connected and switched on. Unpacking The 557 Stereo Power Amplifier comes in a box containing the following components: r 557 Stereo Power Amplifier. You are advised to retain the packing in case you need to Setting up the Stereo Power Amplifier Once set up, the Stereo Power Amplifier can be left switched on as it consumes negligible power when not in use. If you are not going to use the Stereo 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. To position the Stereo Power Amplifier During normal operation the heatsinks, ie the fins at each end of transport the unit. Do not attempt to lift it without assistance. The Stereo Power Amplifier should therefore be positioned to allow a free flow of air around the fins. Before connecting power Do not place the Stereo Power Amplifier: Before you begin installation you should ensure that your Stereo 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. r Stacked with any other audio products, as the heat it generates may damage the other products. 8 Connecting the Stereo Power Amplifier Back panel Input (R) Outputs (R) Outputs (L) Input (L) RIGHT LEFT - - Setting up the Stereo Power Amplifier + + INPUT BRIDGE MODE INPUT BALANCED INPUT OFF OFF BALANCED INPUT BRIDGE MODE INPUT ON BRIDGE MODE ON Balanced input (R) Bridge mode switch Balanced input (L) 9 Outputs The following table gives details of the output connections: Use this output LEFT, RIGHT To connect to this Loudspeakers of 4 to 15, using either plug or bare wire connections. BRIDGE MODE Setting up the Stereo Power Amplifier Inputs The following two alternative audio inputs are provided: Use this input LEFT INPUT, RIGHT INPUT BALANCED INPUTS To connect to this A preamplifier, using phono connectors and high-quality screened cable. A balanced analogue output, using XLR connectors: 1 (Green) = GND 2 (Red) = +ve 3 (Black) = -ve When using the balanced inputs the phono inputs should be shorted, using the two phono shorting plugs supplied. A loudspeaker of 6 to 15; see To wire to an A500 Loudspeaker in bridge mode, page 12. Each channel of the 557 Stereo Power Amplifier provides twin outputs for bi-wiring. On speakers that provide separate connections to the bass/mid and tweeter units this allows the units to be connected independently to the Stereo Power Amplifier, for optimum sound quality. Alternatively, for loudspeakers providing a single pair of inputs, either of the output terminals can be used. 10 To connect to a conventional preamplifier q Connect the sockets marked INPUT on the back panel of the Stereo Power Amplifier to the outputs from your preamplifier. 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. To connect to A500 Loudspeakers A500 Loudspeaker A500 Loudspeaker 557 Stereo Power Amplifier Setting up the Stereo Power Amplifier To connect to a 501 Control Unit q Set the BRIDGE MODE switch to the OFF position. 557 Stereo Power Amplifier q Use the links provided to bridge the HF and LF terminals on 501 Control Unit OUTPUT INPUT INPUT the back of each loudspeaker. q Connect one of each pair of the red and black terminals on the back panel of the 557 Stereo Power Amplifier to the red and black terminals on the A500 Loudspeakers. Audio lead q Connect the sockets marked OUTPUT L and R on the back panel of the 501 Control Unit to the INPUT sockets on the back panel of the 557 Stereo Power Amplifier. 11 To bi-wire to A500 Loudspeakers A500 Loudspeaker A500 Loudspeaker To wire to an A500 Loudspeaker in bridge mode A500 Loudspeaker 557 Stereo Power Amplifier 557 Stereo Power Amplifier Setting up the Stereo Power Amplifier ON q Set the BRIDGE MODE switch to the OFF position. q If necessary, remove the links bridging the LF and HF terminals on the back of each loudspeaker. q Connect the LF red and black terminals from each loudspeaker to the red and black terminals on the appropriate channel of the Stereo Power Amplifier, using twin loudspeaker cable. q Connect the HF red and black terminals from each loudspeaker to the other pair of red and black terminals on the appropriate channel of the Stereo Power Amplifier. Input You can use the 557 as a mono power amplifier, to obtain more than three times the power output, by wiring it in bridge mode. q Switch the BRIDGE MODE switch to the ON position. [. . . ] Outside the UK, local warranty liability is restricted to equipment packaging, to your Meridian dealer. In case of difficulty within the UK or USA please contact the appropriate sales and service address shown on page ii. 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. [. . . ]