Hafler DH-500 manuale d’uso

_^.,_.. ._.. ,..-I_ THE POWE R 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 THE DAVID HAFLER COMPANY 5910 Crescent Boulevard, Pennsauken, New Jersey 08109 Please refer to this serial number in all communicati[...]

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-0.00[...]

INTRODUCTION The Hafler DH-500 is a two channel audio power amplifier designed to the very highest performance stan- dards. It is available as a kit, or factory assembled. Its power rating of 255 watts per channel is very conservative, and it can deliver appreciably higher powers into impe- dances below the rated 8 ohms. You must be very cautious i[...]

INSTALLATION The DH-500 may be installed out of sight in many appli- cations, where its power can be controlled by the AC switching of a preamplifier control unit. However, any high power amplifier may draw enormous amounts of cur- rent, so you should make sure your preamplifier has the switching capacity for the amplifier ’ s needs, as well as a[...]

If the manufacturer of your speakers recommends a specific fuse value for their protection, you should obtain 3AG type fuses of that value and substitute them for the ones supplied. The speaker fuses are included in the amplifier design solely for speaker protection. They do not protect, or affect, the amplifier ’ s operation. A blown speaker fus[...]

number of specialty speaker cables preferred by perfec- tionists. If you have 4 ohm speakers, larger wire is recom- mended than for the typical 8 ohm speakers, too. The black output terminals are connected to ground in- ternally. The black terminals may be connected together (common ground) when in the normal stereo mode, to utilize headphone junct[...]

4. Allow the connection to cool undisturbed. Remember that the connection is made by the solder, not by mechanically attaching the wire to the terminal. Usually the wire is looped through the lug and crimped in place, but some prefer to just place it through the hole and rely on the stiffness of the wire to hold it while soldering. Eyelet connectio[...]

MECHANICAL ASSEMBLY 1 0 For security in shipping, the power transformer and the amplifier module have been fastened to the chassis. Remove the chassis cover, the inner front panel and the larger front plate, and set these aside. Be particularly careful in handling the amplifier module. to see that the leads of the upright compo- nents on the circui[...]

90 10 11 12 Selec t the plastic encased relay, the longer L-shaped mounting bracket, and 2 sets of hard- ware. Insert the screws through the bracket with the bracket foot pointing away from the lugs at the opposite end of the relay. ‘ lighten this hardware se- curely, but do not risk breaking the plastic. Selec t 2 sets of hardware an d mount the[...]

There are two gauges of wire supplied with the kit. For While excessive heat or careless “ scrubbing ” with the iron connections which pass substantial current, the heavier can lift the circuit foil from the board, more people tend to wire is used. Other connections need only the lighter gauge use insufficient heat, making it difficult for the [...]

40 0 Prepare two 9 ” white wires. Connect one to eyelet 5 2 q Select the spade lug and connect it to the free end of #8 of the left board. (S). Connect the other to the white wire from LT lug 6. Place this wire to the eyele t #6. (S). Bend these toward the bottom, and left, and twist it lightly together with the green wire twist them together. fr[...]

62 0 Prepare a 3 ” white wire. Connect one end to RY lug #4. (S). Connect the other end to red output termi- nal LR. (S). 63 [7 Prepare another 3 ” white wire. Connect one end to RY lug #6. (S). Connect the other end to output terminal RR. (S). 64 0 Prepare a 16 ” green wire. Connect one end to black output terminal LB. (S). Connect the other[...]

80 0 Select the triad of black, red and yellow wires from under the module. These will be connected to the right end of the terminal strip, and to prevent the heat from the large resistors from melting the insu- lation on the wires, connect the wires from behind the terminal strip and keep them against the chas- sis, so the resistors will be above [...]

97 0 Select the .Ol mfd disc capacitor and trim each lead t o 3/4". Strip two 1/2" lengths of insulation from a piece of heavy wire, and install these on the capacitor leads. Connect one lead to DB lug #l. (S-3). Connect the other lead to DB lu g #4. (S-2). 98 0 Select the power switch and the .OO5 mfd disc capacitor. Wit h the red window[...]

CIRCUIT DESCRIPTION The DH-500 amplifier components have been selected to pro- tect against failure, and all parts are operated conservatively to assure unaltered performance and proper operation for many years. The semiconductors have been thoroughly researched and selected for minimum noise and distortion in sustained use, and the printed circuit[...]

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All resistors are ‘1’4 watt 5% carbon film unless otherwise noted. part N,,. Rl R2 R3 R4 R5 R6 R7 R8 R9 RIO RI1 RI2 RI3 RI4 RI5 R16 RI7 RI8 RI9 R20 R21 R22 R23 R24 R25 R26 R27 R28 R29 R30 R31 R32 R33 R34 R35 R36 R37 R38 RIO1 R102 RI03 R104 RI05 R106 R107 RI08 RIO9 Rl IO Rll l RI 12 R113 R114 Rl15 Rl16 Rl17 RI18 RI19 RI20 R401 R402 R403 R404 R40[...]

A C LINE CONNECTIONS FOR OVERSEAS USE Th e power transformer supplied in DH-500 amplifiers sold in multi-voltage transformer is installed. This, the 600 oh m the USA is intended for 120 volt , 60 Hz operation only. For use resistors, the mounting hardware, and the alternate line fuse are in other countries, a multi-voltage transformer is supplied i[...]

KIT PARTS LIST SMALL PARTS ENVELOPE Minor variations may sometimes be encountered in value or appear- ance. These will not affect performance. Some of the hardware listed here has been used to secure parts for shipping the kit. 2 1 1 Bracket, L-shape, 2 ” Bracket, L-shape, 3 ” Capacitor, 0.005 mfd Disc Capacitor, 0.01 mfd Disc Capacitor, 0.39 m[...]

DH-502 INSTALLATION INSTRUCTIONS 1. 3 2. 3 3. cl 4. El 5. 6. 0 7. 8. c! 9.3 Disconnec t AC power from the DH-500 and remove al l connect- ing cables. Remove the 1 7 screws which secure the cover along the top front, sides and rear. Set cover aside. DO NOT GRAB THE AMPLI- FIER PANEL OR HANDLES WHEN TH E COVER IS RE- MOVED. You might bend the chassis[...]

INSTRUCTIONS FOR TH E HAFLER DH-502 AMPLIFIER BRIDGING KIT FOR THE DH-500 The DH-502 Amplifier Bridging Kit for th e DH-500 consists of a PC-7A circuit board comprising a 6 transistor phase inverting amplifler, a mounting bracket, necessary hardwareandconnecting wire. Installation may take about an hour. All changes to the amplifier wiring are perf[...]

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The DH-500 Power Amplifier has been carefully en- gineered to provide many years of use without requiring any maintenance or servicing. Factory assembled units are subjected to many physical and electrical tests before shipment. The amplifier module assemblies of kit units are similarly tested to meet perfor- mance specifications prior to packing. [...]