User manual HAFLER DH-500

[. . . ] _^. , _. . . _. . , . . -I_ THE POWER AMPLI FIER for ASSEMBLY and OPERATION CAUTION: IF THE FUSES BLOW, SOME DISTORTED SOUND CAN BE HEARD. THEREFORE IF AMPLIFIER MALFUNCTIONS, ALWAYS CHECK FOR BLOWN FUSES FIRST. LM153 $3. 00 Please refer to this serial number in all communications regarding this equipment. THE DAVID HAFLER COMPANY 5910 Crescent Boulevard, Pennsauken, New Jersey 08109 DH-500 Power Rating: Less than 0. 025% total harmonic distortion at any power level up to 255 watts continuous average power per channel into 8 ohms at any frequency between 20 Hz and 20 kHz with both channels driven. IM Distortion (SMPTE): Less than 0. 007% from 1 watt to 255 watts into 8 ohms Typical THD at 255 watts into 8 ohms: 1 kHz-0. 002%; 10 kHz-0. 007% Frequency Response into 8 ohms: -3 dB, 0. 5 Hz to 120 kHz at 1 watt kO. 5 dB, 5 Hz to 40 kHz at 255 watts Typical Channel Separation at 1 kHz: 60 dB Signal to Noise Ratio: Exceeds 100 dB referred to 255 watts into 8 ohms, unweighted Exceeds 90 dB referred to 1 watt into 8 ohms, A weighting Input Impedance: 47, 000 ohms Input Sensitivity: 2. 35 volts for 255 watts into 8 ohms; 0. 145 volts for 1 watt Damping Factor: 200 to 1 kHz into 8 ohms; 60 to 10 kHz into 8 ohms Rise Time: 10 kHz, 80 volts p/p square wave, 10% to 90%: 2. 5 us. Slew Rate: 1 kHz, 120 volts p/p square wave: 45 V/us. [. . . ] If the eyelet is first filled with solder, and the wire end is pushed all the way through the heated eyelet first, then withdrawn part way to expose a bit of the bare end outside the board before the solder cools, you should have a firmly soldered connection if it cools undisturbed. q q q Always tin a wire that is to connect to an eyelet. After soldering, go back and check by twisting each wire, to make sure nothing moves on the other side of the board. It is wise to check any existing wire connected to an adjacent eyelet, to make sure your work has not loosened it. When connecting heavy gauge wire to the eyelets, if you get too much solder on in the tinning process, it will be hard for the wire to penetrate the eyelet. 10 Prepare a 6-1/2" white wire and connect it to eyelet #3 of the right board. Prepare a 13" green wire and connect it to eyelet #7 of the left board. Prepare a 13" white wire and connect it to eyelet #5 of the left board. Bend this wire toward the bottom. 38 39 40 0 Prepare two 9" white wires. Connect one to eyelet #8 of the left board. Bend these toward the bottom, and twist them together. 41 0 Prepare a 3" white wire and connect it to eyelet #3. 42 0 Prepare a 6" green wire and connect it to eyelet #10 (S). Set the module aside temporarily. 52 q Select the spade lug and connect it to the free end of the white wire from LT lug 6. Place this wire to the left, and twist it lightly together with the green wire from LT lug 3. When connecting wires to the PC-9 circuit board note that the eyelets on this board are numbered in the reverse direction from the lug numbers on the terminal strip. CHASSIS WIRING 43 0 Select the chassis and the . 39 mfd capacitor. Connect one lead of the capacitor to L T lug #3. Note that one end has a stripe for identification. 45 0 Select the 1/2 watt 1 megohm (brown-black-green) resistor. Trim each lead to l/2" and connect one lead to LT lug #2. Connect the other end to fuse clip FC lug #l. Connect it to the other end of the green wire just attached to lug #3. The proper way to connect one of the spade lugs to the wire is to bend the shorter, wider set of tabs tightly around the bare wire, and bend the outer, longer set of tabs around the insulation. Then flow solder into the joint around the bare wire. [. . . ] If you return an amplifier for service or checkout, and it is functioning correctly, a charge will be made for the testing time required, as well as for packing and shipping. WARRANTY FOR KIT-BUILT UNITS The parts in a DH-500 kit are warranted for a full year from the purchase date. If a defective component is found on a circuit board or in a kit, simply return the individual part to the factory prepaid together with the serial number and the date of purchase, and it will be replaced at no charge. If you cannot locate what is wrong with your DH-500, 1. Complete shipping address (Post Office box numbers are not acceptable, except for correspondence). [. . . ]