User manual YAMAHA C-4

[. . . ] Connect this unit's power cord only to an AC outlet of the type stated in this Owner's Manual or as marked on the unit. Failure to do so is a fire and electrical shock hazard. Do not scratch, bend, twist, pull, or heat the power cord. A damaged power cord is a fire and electrical shock hazard. [. . . ] If the airflow is not adequate, the unit will heat up inside and may cause a fire. To mount several of these units in an EIA-compliant rack, refer to the rack mounting instructions on page 8. This unit has ventilation holes at the (top, bottom, front, rear, and sides) to prevent the internal temperature rising too high. Blocked ventilation holes are a fire hazard. Clean the contacts of the phone plug before connecting it to the SPEAKERS jack of this unit. Use only speaker cables when connecting speakers to amplifier outputs. Using other types of cables is a fire hazard. Hold the power cord plug when disconnecting it from an AC outlet. A damaged power cord is a potential fire and electrical shock hazard. Do not touch the power plug with wet hands. Doing so is a potential electrical shock hazard. · If the amplifier overheats If the amplifier overheats, the protection system activates. In this case, you should turn off the amplifier and allow it time to cool down. When it has cooled down, the protection system deactivates automatically and the amplifier can be turned on again ready for normal operation. See the Precautions section of this Owner's Manual for ways to prevent the amplifier overheating. 4 SIGNAL indicator A channel's SIGNAL indicator lights up when its output exceeds 2 V rms, which is equivalent to 1/2 watt into 8 ohms, or 1 watt into 4 ohms. 4 s Rear Panel 1 2 3 5 6 8 80 4 7 * The illustration shows model XM6150. 1 HPF switches These switches are used to turn on and off the HPF (High Pass Filter) for each channel. When set to ON, frequencies below 80 Hz are filtered using a 12 dB/ octave high pass filter. Turn this switch ON if 70V-line, high-impedance speakers are connected. In Bridge mode, only the HPF switch of the first channel in the pair is active, i. e. , channel A of pair A­ B, channel C of pair C­D, and channel E of pair E­F (XM6150 only). 4 Euroblock connectors These balanced Euroblock connectors are used to connect input signals. In Bridge mode, only the Euroblock connector of the first channel in the pair is active, i. e. , channel A of pair A­B, channel C of pair C­D, and channel E of pair E­ F (XM6150 only). 5 CH A TO ALL CH switch This switch is used to feed the input signal connected to channel A to all channels. When set to EACH CH, the input signal connected to each channel is amplified and output by each channel respectively. When set to CH A TO ALL CH, however, the input signal connected to channel A is fed to all channels. 2 Attenuators These detented controls are used to attenuate the input signal from ­ dB to 0 dB for each channel. In Bridge mode, only the attenuator of the first channel in the pair is active, i. e. , channel A of pair A­B, channel C of pair C­D, and channel E of pair E­F (XM6150 only). 6 BRIDGE switches These switches are used to bridge the following channel pairs: A­B, C­D, and E­F (XM6150 only). When set to OFF, the two channels operate independently. For example, the signal connected to input channel A is amplified and output by the channel A outputs, while the signal connected to input channel B is amplified and output by the channel B outputs. When set to BRIDGE, the signal connected to input channel A is amplified and output by the bridged outputs A­B, and channel B's inputs are not used. 3 XLR inputs These balanced XLR-3-31 type connectors are used to connect input signals. [. . . ] Reattach the protective cover over the speaker terminals. 15mm* 7 Air Flow This unit uses a forced cooling system in which air comes in through the front opening and goes out the sides and rear. Side View Front Rear View Air intake Air exhaust 80 Air exhaust Rack Mounting If multiple high-power amp units are mounted in a rack with poor ventilation, the heat from the amps will cause the interior of the amp to become very hot, causing the performance of the amps to be impaired. In particular, when mounting in a rack whose back can not be left open, mount according to the following instructions. Rack: Leave a gap of 10 cm or more between the rear panel of the rack and the rear panel of the amplifier. Fan: Use a fan with 1. 5 m3/min or more maximum wind and 5 mmH2O or more maximum static pressure. [. . . ]