Fender 2150 Power Amplifier Owners Manual - Page 6

BASIC WIRING AND CONNECTIONS Power and audio signal cables are the most common sources of sound system failure. Well made and carefully maintained cabling is essential to the reliability of the whole system. If long speaker cables are required, make sure the wire is of sufficient size to transfer all the available amplifier power to the speakers rather than absorbing power itself. As a rule of thumb, the larger the wire, the better (larger wire has smaller "gauge number"). Large diameter (small gauge number) wire is expensive and long cables made from it are heavy. Rather than running long speaker cables, it's better to locate power amplifiers near speakers and run a line-level signal cable over the long distance to the amplifier. This approach eliminates most of the signal loss due to speaker cable resistance so the speakers will be fed all the amplifiers's power without the need for heavy cables. It can actually save money in many instances. Always use stranded wire for two reasons: (1) It is more flexible and less prone to metal-fatigue breakage. (2) If an end is nicked while insulation is being stripped for connection, only one or two strands will break, not the entire wire. CAUTION: Never use coiled cords for speaker hookup, even in an emergency. Coiled guitar-type cords usually have higher internal resistance than the speakers themselves. This is due to the light-gauge wire used to keep the coil cords flexible. These cords will prevent most of the power from reaching the speakers. In high power operation, a coil cord can melt, cause a fire hazard, and possibly damage the amplifier. As a general rule, guitar-type connecting cords, both straight and coiled, make poor speaker cables. The 2150 power amplifier can produce enough power output to damage electronic equipment connected to its output. Besides being capable of destroying speakers, under certain circumstances shock and/or fire hazards are possible. High power amplifiers should always be properly applied and used with care in clean and dry environments. Assuming you're NOT turning all the equipment on at once with a switched power receptacle "strip", be sure to turn on the power amplifier last. This will prevent turn-on "thumps" from the other pieces of gear from possibly damaging speakers. The reverse logic should be used-turn OFF the amplifier FIRST-when shutting the system down. The 2150 is timed to turn on the speaker outputs after the amplifier's power supply is fully charged up, thus preventing any turn-on noise. Timing of the amplifiers's turn-on circuit is usually sufficient to accommodate all of the turn-on anomalies from other pieces of gear in a system, making it acceptable to use a single switched power string in a permanent or semi-permanent system. In multiple amplifier installations, we recommend sequential turn-on (either manually or via timed relays) to avoid a sudden, major drain on the AC line. You should keep in mind that severe reduction of power line voltage affects the amount of power you can get FROM the amplifier. If you need to run long AC extension cords, make sure their conductors are as large as practical (small gauge number). Just as smaller diameter wire causes speaker line loss, smaller power lines cause loss.