19 c3 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). Connect the green wire to terminal RB. Place these wires off to the right.

2 1 C Prepare a 51/2" green wire. Connect one end to terminal RB. (S-2). Place this wire towards the center of the chassis.

22 0 Prepare a 16” green wire, but strip 11/4" of insulation from one end. Prepare a 15” white wire. Start with the normally stripped (l/4”) ends even, and twist these wires uniformly together. Thread the longer bared end of the green wire through LS short lug #2 from the top left, then through GLlug #3, and connect it to RSshort lug #4. Solder only LS lug #2. Connect the corresponding end of the white wire to LS lug #l. (S). Place this wire up under the chassis rear lip, above the output terminals, and off to the left.

23 L! Prepare a 61/2" green wire. Connect one end to CL lug #3. (S2). Place this wire over the rear of the chassis.

24 C Prepare a 10” green wire and a 10” white wire. Twist these together with the ends even. Connect the green wire from the right to RS short lug #4. (S-2). Connect the white wire to RS lug #5. (S). Place these wires off to the right.

25 0 Prepare two 22” white wires, and twist them together throughout their length. 8” in from one end of the pair, cut one of the wires, and unwind it about 11/2" in each direction from the cut. Strip 1/4" of insulation from each of these cut ends. Place the longer portion of the wire along the lower front edge of the chassis, with the break at the terminal strip TS. Connect the cut end from the left to TS lug #2. Connect the other end to the lower hole of TS lug #5. (S). Place this pair along the front edge of the chassis, under the power switch, with the ends project- ing from the front corners of the chassis.

26 il Select a 1 megohm resistor (brown-black-green) and trim the leads to 1/2”. Connect one lead to TS lug #2. (S3). One of these 3 leads has already been soldered to the lower lug hole. Connect the other lead to TS lug #3.

27 n Select the diode and trim its leads to 1/2”. Note that one end of the diode is marked with a stripe (or an arrow head will point to that end). Connect the marked end to TS lug #4. Connect the other lead to TS lug #3. (S2).

28 0 Prepare a 4” green wire. Connect one end to TS lug #4. Select a spade connecting lug, and solder it to the other end. Place this wire down against the chassis, and con- nect it to the PS lug on the right, near the edge of the chassis.

The proper way to attach a spade lug to a wire is to first cut the bared wire end to the right length (no more than 1/4" so that the insulation will be securely gripped by the longer, outer tabs, while the wire does not protrude into the spade clamp area. Tin the bare wire end. Bend the

shorter, middle set of tabs tightly around the bare wire, and then bend the longer tabs around the insulation. Then flow solder into the joint around the bare wire, keeping the solder away from the spade section.

29Prepare a 2” white wire. Connect one end to FC lug #2.

(S). Select another spade lug, and solder it to the other end. Connect it to the PS middle lug.

300 Select the 0.39 mfd (.39K) capacitor and trim its leads to 1/2" Connect one lead to TS lug #4. (S3). Connect the other lead to TS lug #5.

310 Select the two large round capacitor brackets, the two large capacitors, and 6 sets of #6 hardware. Place a bracket around the bottom of each capacitor, and fasten it snugly with one set of hardware through the clamp. Note the direction of insertion of the screw for easy ser- vicing access in the future. The clamps need not be tightened now - just made snug. Place each assembly on the chassis, at CL and CR, noting the position of the clamp, and fasten them securely. Be sure no wires are trapped by the bracket. Then loosen the clamps, and position the capacitors so that each + terminal is posi- tioned as in the pictorial diagram. The + terminal will usually be so marked, but if not, it may be identified by a red dot. Note that the + terminal of CL is nearest the - terminal of CR. Make sure the capacitors are seated against the chassis and tighten both clamps.

32 0 Select the 4 plain solder lugs and then 4 short #lO SEMS screws (with lockwasher attached). Install these in the capacitors, with the lugs pointing as in the diagram.

33 C Prepare a 6” green wire. Connect one end to DB lug #l.

(S). Connect the other end to CL lug #l.

34 E Prepare a 4%” green wire. Connect one end to FL lug #l . (S-2). Connect the other end to CL lug #l. (S2).

35 G Prepare a 6” white wire. Connect one end to DB lug #4.

(S). Be sure this is the + terminal of the rectifier. Connect the other end to CR lug #2.

36 q Prepare a 43/4" white wire. Connect one end to FRlug #3. (S-2). Connect the other end to CR lug #2. (S2).

37 •1 Remove all insulation from a 3” white wire. Connect one end to CL lug #2. (S). Connect the other end to CR lug #l.

(S).

38 [7 Select the power transformer, the 4 flat washers, and the 4 sets of #10 hardware. Position the transformer with the red leads to the center rear of the chassis, and the black and black/white leads towards the power switch. If the transformer is the special multiple voltage version, the additional leads should be placed as shown else- where in this manual for the desired line (mains) voltage.

The red/yellow lead will likely be the correct length. If you wish to shorten the red leads for neatness in con- necting them to the rectifier terminals, it is easier to strip them before the transformer is mounted.

Place the white pair of wires under the front chassis lip. Install a flat washer on top of each transformer foot after the screw is inserted from below, and then add the nut. Be sure no wires are trapped.

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Hafler DH-200 manual

DH-200 specifications

The Hafler DH-200 is a well-regarded power amplifier that has earned a dedicated following among audio enthusiasts since its release in the early 1980s. Known for its excellent performance and reliability, the DH-200 has become a staple in many home audio systems.

One of the key features of the DH-200 is its high power output, delivering 100 watts per channel into 8 ohms and 200 watts into 4 ohms. This robust power handling capability makes it suitable for driving a wide range of speakers, from compact bookshelf models to larger floor-standing designs. The amplifier's low distortion and high current output ensure that it can reproduce dynamic and intricate musical passages with clarity and precision.

The DH-200 utilizes a unique circuit topology that incorporates a high-performance, complementary push-pull output stage. This design minimizes crossover distortion while providing excellent linearity and frequency response. The frequency response extends from 20 Hz to 20 kHz, matching the full range of human hearing and allowing for a natural reproduction of both low and high frequencies.

Another notable technology in the DH-200 is its use of a toroidal transformer, which contributes to the amplifier's efficiency and low noise operation. Toroidal transformers are known for their compact size, reduced electromagnetic interference, and improved power supply regulation, which translates into cleaner audio performance.

In terms of build quality, the Hafler DH-200 features a rugged chassis and a minimalist front panel design. The amplifier is a two-channel unit, with individual volume controls for each channel, allowing for precise adjustments. The rear panel is equipped with standard RCA input connections and binding posts for speaker outputs, making it compatible with most audio sources and speaker systems.

The DH-200 is also praised for its thermal management, featuring multiple heat sinks to dissipate heat effectively during extended use. This design helps to ensure long-term reliability, even under demanding listening conditions.

In conclusion, the Hafler DH-200 is a power amplifier that stands out for its exceptional sound quality, powerful performance, and robust build. Its combination of advanced technologies, such as a complementary push-pull output stage and toroidal transformer, make it an enduring choice for audiophiles seeking a reliable and high-performing amplifier for their home audio systems. Whether for casual listening or critical listening sessions, the DH-200 has proven to be a versatile and gratifying component in any audio setup.