The power amplifier instructions for operation and kit assembly caution: if the speaker fuses blow, some distorted sound can be heard. Therefore if amplifier malfunctions, always check for blown fuses first. Serial number in all communications the david hafler company 5910 crescent boulevard, pennsa...
Introduction the hafler dh-220 is a two channel audio power amplifier designed to the very highest performance standards. It is available either as a kit, or fully assembled. Its 115 watt per channel power rating is sufficient for driving all loudspeakers in home applications, and its design assures...
Installation the dh-220 is most likely to be installed out of sight in most applications, since its power may be controlled by the ac switching of most audio preamplifiers, like the hafler dh-110. If your control unit does not provide switching capacity sufficient for the amplifier’s 7 amp needs (pl...
Performance. Special low capacitance cables enable even greater distance between preamp and amplifier. It is desirable to keep the left and right input cables close together throughout their length to minimize the likelihood of hum pickup. Also, you should avoid running them parallel to ac cords - t...
A soldering “gun” is not recommended. The unfamiliar user is more likely to damage the etched circuit boards with its higher heat potential and unbalanced weight. Also, because he may not wait long enough for it to reach operating temperature each time it is switched on, poor solder connections are ...
Wiring the kit if any components are unfamiliar to you, checking the pic- torial diagram should quickly identify them. Or, the quantities, and the process of elimination as you check the parts list, will help. The pictorial diagram is necessarily distorted to some ex- tent for clarity, so that you c...
5 select the two round fuse holders, and two each 1/2” rub- ber washers, lockwashers and nuts. First install the rub- ber washer on the holder, so it will be outside the chassis, and then fasten the fuse holders at lf and rf, with the tip lugs pointing towards each other, toward the center of the ch...
19 prepare a 7” green wire. Connect one end to terminal lb. (s-2). Place this wire towards the center of the chassis. 20 ll prepare a 10” white wire and a 10” green wire. Starting with the white wire 3/4" longer, twist them together. Con- nect the projecting white wire to red terminal rr. (s). Conne...
The transformer leads may be trimmed as desired for a neat job, but be sure you do not cut any of them too short (particularly if yours is the multi-voltage version, and any change to a different supply voltage is likely). Cutting the leads too short for re-use may void its warranty, if it is though...
55 56 57 58 59 60 61 62 63 64 select the white pair of wires at the front of the chassis. Tuck the excess-wire into the corner and connect one wire to each of the lugs on the thermal breaker. Solder each. Select the left output module, check it as before to see that underside connections near the ho...
Bias remove the b + fuse f2. This fuse is in the line from the ’ +’ c a p a c i t o r terminal to hole # 3 on the board. Connect an ammeter’s ' + ' !Ead to the fuse clip nearest the large filter capacitors. Connect the’ -’ lead to the other side of the fuse clip. Avoid intermittent connections, and ...
The power transformer supplied in dh-220 amplifiers sold in the ljsa is intended for 120 volt, 60 hz operation only. For use in other countries, a multi-voltage transformer is available at higher cost. It has dual tapped primary windings which can be arranged in various series-parallel combinations ...
Kit parts list minor variations may sometimes be encountered in value or appearance. These will not affect performance. Part no. Fuse envelope 6 fuse, 5 ampere 2 fuse, 2 ampere 1 fuse, 7 ampere, slo-blo 1 additional fuse, 4 ampere, slo-blo (international use only) 1 1 2 2 1 4 2 1 2 2 1 2 2 2 1 1 1 1...
Component values all resistors are l/4 w carbon film unless specified otherwise rl 470,000 ohms r2 1,800 ohms r3 47,000 ohms r4 47,000 ohms r5 1,000 ohms r6 1,000 ohms r7 47,000 ohms r8 560 ohms r9 560 ohms rio 1,800 ohms rll 1,800 ohms r12 270 ohms r13 47 ohms r14 47 ohms r15 47 ohms r16 47 ohms r1...
Specifications power rating: less than 0.02% total harmonic distortion at any power level up to 115 watts continuous average power per channel into 8 ohms at any frequency between 20 hz and 20 khz with both channels driven. Input impedance: 47,ooo ohms. Input sensitivity: 1.55 volts rms for 1 15 wat...
Instructions for the hafler dh-222 amplifier bridging kit for the dh-220 the dh-222 may be installed in a hafler dh-220 power amplifier to enable easy conversion to a high power monophonic amplifier, bridging the two conventional chan- nels to a single floating output which can deliver in excess of ...
Dh-222 installation instructions disconnect ac power from the amplifier, and remove all con- necting cables. Wait 5 minutes to allow capacitors to discharge before proceeding with disassembly. Remove all 8 screws between the fins of each amplifier module so that the cover may be removed, and the mod...
