User manual YAMAHA P2250

[. . . ] However, if you are using the P-2200 in an existing system, and you are familiar with high power amplifiers, the BRIEF OPERATING INSTRUCTIONS, Pages One 1 & 2, contain all the information necessary for basic connections and operation. The SPECIFICATION sections, (Sections THREE and FOUR) are highly detailed, including oscilloscope photos, and discussions of the P-2200's excellent performance specifications. The last part of the SPECIFICATIONS section is a discussion of the advantages of professional equipment, like the P-2200, compared to hi-fi or semi-pro equipment. The INSTALLATION AND DETAILED OPERATION section, which begins on Page SIX 1, includes more complete instructions, special considerations for using the P-2200 "on the road, " as well as in permanent commercial and studio installations. [. . . ] Insert the locking tab in the female insert, as illustrated, with small nib facing front of connector. Slide insulating collar foward, up to rear edge of female insert. The outer insulation of the cable must be flush with, or covered by the end of the insert. If any of the center conductors are visible, the cable clamp may not be able to grip the cable firmly, and the connector leads will soon fatique. Then slide the collar back into the shell. Slide the shell forward, orienting the notch in the shell with the locking tab in the insert. Place the cable clamp over the rear of the shell, with careful attention to the clamp's orientation; a raised lip inside the clamp should be aligned immediately over a lip in the shell for thinner cables (No. 8412), the clamp should be turned around to offset the lips and provide more clearance for the cable. Insert the clamp screws and tighten fully. WIRING A STANDARD PHONE PLUG (2-conductor) Parts identification. Slide shell, then insulating collar over cable end. Strip outer insulation for length equal to length of sleeve connection. Unwrap or unbraid shield, twist to form lead. Position outer insulation just ahead of cable clamp, strip center conductor from point just behind tip connection. Bend shield as illustrated, solder to outer surface of sleeve connection. (Cool immediately with pliers. ) Insert center conductor in tip connection, solder, cut end flush. 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). Thus, as the impedance of the load goes down, the total power delivered by the P-2200 goes up. Note that when the impedance of the load falls below 2. 5 ohms, the P-2200's protection circuitry begins to limit the total amount of power delivered. For purposes of calculating the total load impedance that is presented to the P-2200, assume that speaker impedances do not change with frequency. The Appendix shows various series and parallel combinations of speakers and the effective loads they present to the P-2200. Formulas for the power delivered to each speaker in a parallel or series combination are included. Fig. NOTE: Impedance changes when loudspeaker is installed in a cabinet. The impedance of 70-volt speaker transformers also falls with frequency, especially in lower quality transformers. (Note that a "perfect" transformer would not have any impedance of its own. ) If low efficiency 70volt transformers are used, the system will need more transformers and speakers to achieve the same SPL than if higher quality transformers were used. Thus, "economy" transformers, may actually cost more in the long run than higher quality professional types. For an existing system with lower quality 70-volt transformers, a capacitor in series with the output of the P-2200 can limit the current at low frequencies (see Page SEVEN 6), and thereby avoid the possibility of constant protection circuitry operation on the P-2200, or damage to the 70-volt transformers from excessive output power from the P-2200. Transients and DC Protection The P-2200 displays virtually no turn-off transient, and the turn-on transient is minimal. [. . . ] A BALANCED circuit requires either a center tapped transformer, or resistors from each side of the transformer to ground; either condition places both sides of the transformer at equal potential with respect to ground. 83 - Balanced vs Floating Circuits NOTES: "N1 " is the number of turns on the primary side of the transformer, " N 2 " is the number of turns on the secondary side of the transformer. "V 1 " is the voltage level on the primary side of the transformer, " V 2 " is the voltage level on the secondary side of the transformer. "I 1 " is the current level on the primary side of the transformer, " I 2 " is the current level on the secondary side of the transformer. [. . . ]