User manual YAMAHA P2201

[. . . ] YAMAHA AUTHORIZED PRODUCT MANUAL P-2200/2201 SYSTEM AMPLIFIER P-2200/2201 OPERATING MANUAL ABOUT THIS MANUAL SCOPE The P-2200 is a system oriented amplifier, made to be used in conjunction with mixers, consoles, frequency dividing networks and speakers -- those made by Yamaha or by other manufacturers. Like any power amplifier, the P-2200's performance depends on system design and installation, in addition to its own capabilities. Thus, the P-2200 Operating Manual is system oriented, describing system design parameters and installation techniques, as well as the operation and performance of the P-2200. Additionally, this manual reviews a few of the basic mathematic tools used in system design, from dB to Ohm's law. [. . . ] Clamp should be firm, but not so tight as to cut insulation. Slide insulating collar forward, until flush with rear of threads. WIRING A TIP, RING & SLEEVE PHONE PLUG (3-conductor) Parts identification. Slide shell and insulating collar over cable end. Strip outer insulation for length equal to length of sleeve connection. Hold cable with outer insulation just ahead of cable clamp, and strip the red (or white) conductor just behind the tip connection. Tin all leads, and cut the center conductors so approximately 1/8" of bare wire remains. Solder the shield to the outer surface of the sleeve connection, allowing enough free shield to bend around to the other side of the cable clamp. Insert the center conductor leads in their respective connection points, and solder in place. Bend the end of the tip connection (slightly) toward the ring connection to help prevent the burr (from the cut wire) from cutting through the insulating collar. The clamp should be firm, but not so tight as to cut the insulation. Slide the insulating collar forward, until flush with rear of threads. Slide the shell forward, and screw tightly onto plug. Use of the Input Polarity Switch on the P-2200 The XLR input connectors on the P-2200 are unbalanced. In one position, the switch beside the connectors attaches pin 2 to pin 1 (ground) leaving pin 3 "hot" (USA standard). In the other position, the switch attaches pin 3 to pin 1 (ground) leaving pin 2 "hot" (DIN/JIS standard). If the source feeding the P-2200's input is unbalanced, the switch must be properly set to avoid shorting out the source. If the source is balanced, the P-2200's inputs will unbalance the source. In many situations, this is acceptable, however, the input polarity switch must still be set in the position corresponding to the "hot" pin of the balanced source. If the switch is set in the wrong position, the signal will be inverted at the P-2200's output compared to the signal at the source ("out-of-phase"), Fig. Note that a series connection of two speakers degrades the damping factor (see Page FOUR 7) because each speaker looks back at the amplifier through the impedance of the other speaker. Thus the effective output impedance of the P-2200 as seen by one speaker is equal to the actual output impedance of the other speaker (see Figure 50). Also, the impedance of most speakers lowers with frequency, so that the effective load of two "8 ohm" speakers in parallel across the output of the P-2200 may be as low as 2. 5 to 3 ohms at certain frequencies. Thus, speaker loads much lower than 8 ohm nominal impedance could overload the amplifier, especially if the actual impedance drops far below the nominal impedance. Figure 51 shows the variation of impedance magnititude with frequency for one type of speaker system. Fig. 49 -- Polarity Switch Use Output Impedance Matching Within its rated power and voltage limits, the P-2200 acts very much like a perfect voltage source (see Appendix). [. . . ] "Z 1 " is the impedance of the circuit seen at the primary side of the transformer, "Z2" is the impedance seen at the secondary side of the transformer. Equations: 1. V1/V2=N1/N2 2. l/I2=N2/N1 3. Z1/Z2= [N1/N2]2 OTHER CONSIDERATIONS A transformer actually doesn't have any impedance of its own. It merely transforms an impedance at its primary (according to Equation 3) to a corresponding impedance at its secondary. Thus, the transformer in the above example has an impedance ratio of 15, 000-to600 = 25-to-1. [. . . ]