THE Hafler SE120 POWER AMPLIFIER POWER AMPLIFIER SERVICE MANUAL HAFLER A DIVISION OF ROCKFORD CORPORATlON 613 SOUTH ROCKFORD DRIVE TEMPE, ARIZONA 85281 SPECIFICATIONS POWER RATING: Less than 0.006% total harmonic distortion at any power level up to 60 watts continuous average power per channel into 8 ohms at any frequency between 20 Hz and 20 kHz with both channels driven. IM DISTORTION (IHF): Less than 0.005% from 1 to 60 watts, each channel, into 8 ohms. TYPICAL THD AT 60 WATTS INTO 8 OHMS: 20 Hz: 0.002% 1 kHz: 0.002% 20 kHz: 0.006% FREQUENCY RESPONSE INTO 8 OHMS: -3dB, 4Hz to 2OOkHz at 1 watt. +OdB, -0.5dB,1OHz to 4OkHz at 60 watts. TYPICAL CHANNEL SEPARATION: 2OHz: > 75dB 1kHz: > 85 dB 20kHz: > 65dB SIGNAL TO NOISE RATIO, UNWEIGHTED: Exceeds 1OOdB referred to 60 watts into 8 ohms. INPUT IMPEDANCE: 22,000 ohms INPUT SENSITIVITY: 1.1 volts rms for 60 watts into 8 ohms. DAMPING FACTOR: 100 to 1kHz into 8 ohms, 50 to 1OkHz into 8 ohms. POWER CONSUMPTION: 60 watts both channels into 8 ohms: 300 VA Quiescent: 60 VA SIZE: 3-1/4" high plus 1/2" feet, 17" wide, 9" deep. (83 mm high plus 152 mm, 432 mm wide, 229 mm deep.) NET WEIGHT: 18 lbs. (8.2 kg) SHIPPING WEIGHT: 20 lbs. (9.1 kg) ALL SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE. Stereo/Mono Channel Operation: The SE120 delivers 60 watts continuous average power per channel into 8 ohms. It can be bridged for single channel operation producing up to 120 watts of power into 16 ohms. Input Mode Selector: This switch will allow the user to specify the input signal to the amplifier. A. Stereo Mode: This allows the right and left channels to reach their designated amplifier channels. This mode will deliver more than 60 watts into an 8 ohm load. B. Mono Mode: The SE1 20 can be operated in a bridged mode which drives both channels with the same signal and combines to deliver more than 150 watts into 8 ohms. This disables the right channel input and routes the signal through the left channel. Construction: The simplified construction of the SE120 improves reliability and results in consistent performance. The heavy duty case construction on the SE120 will provide years of durability and trouble free protection. Gold Plated RCA Input Connectors: This provides the most accurate signal transmission and lowest possible loss. Gold-plated terminals are immune to signal deterioration with time that can be caused by corrosion in the connectors. Speaker Output and Power Connectors: For minimum loss power transfer, high definition and oxidization resistance. Protection System: The SE120 is equipped with a unique protection system that constantly monitors the temperature of the output devices and takes corrective action to prevent damage to the amplifier as a result of excessive overheating. @ Copyright 1990. All rights reserved -l- LINE CONNECTIONS AND SWITCHING The SE120 is normally wired for use on 12OV AC power lines, as in the U.S.A. If your line voltage is different, you will need the special Hafler export power transformer which accommodates many other line voltages. Be sure your amplifier is wired for your line voltage before you plug it in. The SEl2O's power switch may be left on, and the amplifier switched remotely by connecting its line cord to the preamplifier (or other control center) which provides a switched AC outlet. Make sure that the control device can supply a current of 5 amperes to the SE 120, in addition to the current required by any other switched units. You may instead connect the amplifier directly to a wall outlet, and control it with its own front panel power switch. no frayed wire ends which could touch adjacent terminals or the chassis. Tin bare wire ends with solder to secure all strands. PHASING: Consistent phase relationships are important when connecting speakers in order to enable full bass reproduction as well as midrange and high frequency time alignment. To be sure all speakers in a system are wired in phase to the amplifier, each ground or - speaker terminal should be connected to its black ground tenninal on the SE 120 and the speakers + terminal to the corresponding red binding post. Speaker connecting cable identifies one wire from the other by the color of the wire, or by marking or coloring the insulation. NOTE: In the special case of monophonic operation of the SE 120, (described later) different speaker connections are employed. GROUNDING: The black output terminals of the SE120 are connected together internally and grounded to the chassis. This facilitates the use of external devices which use a common ground connection, such as some headphone junctionboxes. You must be sure that the ground or shield connection from such a device goes to a black terminal on the SE1 20. NOTE: No such connection may be made when the SE120 is connected for bridged mono operation. CONNECTING CABLES INPUT: Conventional shielded cables, often supplied with preamplifiers, may connect the control center to the amplifier's input jacks. Be sure the cables are not frayed or loosely connected to the plugs, and that the plug's outer shield connection is tight on the jack, to avoid hum. If you wish to install the SE120 more than a few feet from the preamplifier, the permissible cable length to avoid loss of high frequencies is determined by the preamplifier's output impedance and the internal capacitance of the cable. If the output impedance is 600 ohms or less, as with Hafler preamplifiers, and the cable capacitance is less than 50 picofarads per foot, up to 50- feet is acceptable. Ordinary stereo interconnecting cables often have higher capacitance, however, so a good quality low capacitance shielded wire should be used. When making long runs, keep the left and right cables close together, and avoid running them parallel to power wiring to reduce the likelihood of hum pickup. OUTPUT: The wires which connect the speakers to the amplifier should be of sufficient size to preserve the SEl2O's high Standard #18 gauge lamp cord damping factor. Standard #18 gauge lamp cord is satisfactory for up to 15 feet if your speakers are of 8 ohms or higher impedance. A heavier gauge (#16 or larger) wire should be #16 used with 4 ohm speakers or 8 ohm speakers at a greater distance. Special loudspeaker cables which have adequate thickness to accommodate long runs are usually available from audio dealers. The SEl2O's red and black outputs accept standard banana plug connectors, including the double ones with 3/4" spacing. These are the most convenient to use if you will be disconnecting the speakers occasionally. The terminals will also clamp a spade lug, or a bare wire through the hole in the center post. Be sure there are -3- CONVENTIONAL STEREO CONNECTIONS It is best to make all connections with the SE120 switched off. Each of the stereo speakers connects to one horizontal pair of red and black outputs, as identified left or right on back of the SE 120. The input signals connect to the corresponding input jacks, and the mono/stereo switch should be set to stereo. CONNECTIONS FOR MONOPHONIC OPERATION When you wish to drive a single loudspeaker with increased power capability, the SE120 can be operated in a bridged mode which drives both channels with the same signal and combines their output to deliver more than 120 watts into 16 ohms. In this arrangement, the speaker is connected only to the two red output terminals. The left red terminal is + and the right red terminal is the - connection. NO CONNECTIONS MAY BE MADE TO ANY BLACK TERMINAL!! Set the Input Mode Selector switch to mono, and connect the input signal to the left channel input only. IMPORTANT NOTE: Never use a speaker with an impedance of less than 8 ohms when operating the SE120 in the bridged mono mode. The increased current could overheat the amplifier. TRANSISTOR VOLTAGE VALUESDC volts with respect to circuit ground, no signal applied. OPERATION The pilot lamp in the power switch will glow whenever power is applied to the SEl20. If it does not light, check for a blown AC line fuse. The SE 120 is equipped with a unique protection system that constantly monitors the temperature of the output devices and takes corrective action to prevent damage to the amplifier as a result of excessive overheating. Under most conditions, the SE120 heatsinks will dissipate the heat required to maintain safe operating temperatures, and the unit will play continuously. If the amplifier is driven at high volumes into speakers with an impedance of less than 8 ohms, and/or there is inadequate ventilation, the heatsinks could heat to a level that would cause the protection circuitry to shut off the amplifier for a short time (normally less than 15 seconds) to prevent damage. The SE120 will return to normal operation, and if the overheating condition is still present, the cycle will repeat. In this case, check the surroundings of the unit to insure sufficient air flow around the heatsinks and through the vent holes. Otherwise, check the load impedance connected to the outputs to see if it is far below 8 Ohms. FUSES: The SE120 is supplied with a 5 Ampere Slo-Blo AC line fuse and four power supply fuses. If one of these fails, it is usually indicative of a fault which will require professional service. Bias current adjustment for the SE 120 needs to be performed in the following manner: 1. No signal applied to the input, no load on the output of the amplifier. 2. Line voltage to the amplifier should be set at the nominal value for the area. 3. Adjust one channel at a time. 4. With the unit off, remove either the + or - rail fuse in the right channel. Insert the ammeter across the fuse holder. Make sure that the ammeter is set at its highest current scale. 5 Turn the unit on and, after the unit has warmed up for approximately one minute, adjust the ammeter reading for lOOmA. Turn the unit off. AlIow the unit to discharge before removing the ammeter and replacing the fuse. 6. Repeat steps 4 and 5 for the left channel. NAME Ql Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 QlO Qll Q14 Ql5 Ql6 Q17 Ql8 Ql9 Q20 Q21 Q22 Q23 Q24 Q27 Q28 Emitter -.755 -.756 52.3 52.3 51.4 52.1 51.0 -1.157 -51.4 -.578 .711 -.737 -.755 -.756 52.3 52.3 51.4 52.1 51 .0 -1.157 -51.4 -.578 -.518 -.737 Base -.130 -.159 51.7 51.8 50.9 51.5 50.4 -.532 -50.7 -1.153 1.303 -.126 -.130 -.159 51.7 51.8 50.9 51.5 50.4 -.532 -50.7 -1 .I53 -.088 -.126 co llector 51.5 51.7 51.5 51.8 -12.90 50.5 1.294 1.314 -1.151 -53.5 53.5 51.5 51.5 51-7 51.5 51.5 -12.90 50.5 1.294 1.314 -1.151 -53.5 -53.8 51.5 Q12 Ql3 Q25 Q26 Source .778 -.518 .778 -.518 Gate .087 -.088 .087 -.088 Drain 53.8 -53.8 53.8 -53.8 IC VOLTAGE VALUES IC PIN # 1. -48.9 2. -52.2 3. -49.7 4. -53.9 6. -52.1 7. -48.7 8. -38.5 -DCV -54.0 +DCV 54.0 4- ELECTRICAL PARTS LIST ELECTRICAL PARTS LIST SYMBOL NOa RESISTORS R1 PART DESCRIPTION 1.1kOhms, 1/4w, 1% Metal Film 22.1 k Ohms, 1/4 w, 1% Metal Film 47 Ohms, 1/4x, 5% Carbon Film 47 Ohms, 1/4x, 5% Carbon Film 10k OhmS,1/4w, 1% Metal Film 680 Ohms, 1/4w, 5% Carbon Film 10 Ohms, 2w. 5% Metal Film 680 Ohms, 1/4w, 5% Carbon Film 2.2k Ohms, 1/4w, 5% Carbon Film 5.1 k Ohms,5w, 5% Wire Wound 22k Ohms, 1/4w, 5% Carbon Film 1 .Ok Ohms, 1/4w. 5% Carbon Film 1.1kOhms, 1/4w, 1% Metal Film 22.1 k Ohms, 1/4w, 1% Metal Film 10 Ohms, 1w,5% Metal Film 27 Ohms, 1/4w, 5% Carbon Film 47 Ohms, 1/4w, 5% Carbon Film 470 Ohms, 1/4w, 5% Carbon Film 10 Ohms, 2w, 5% Metal Film 220 Ohms, 1/4w, 5% Metal Film 68 Ohms, 1/4w, 5% Carbon Film 47 Ohms, 1/4w, 5% Carbon Film 10 Ohms, 2w, 5% Metal Film 10 Ohms, 2w, 5% Metal Film 30 Ohms, 1/2w, 5% Carbon Film 2.7 Ohms, 1w, Metal Film 10 Ohms, 2w, 5% Metal Film 10 Ohms, 2w, 5% Metal Film l.lk Ohms,1/4w, 1% Metal Film 22,1 k Ohms, 1/4w, 1% Metal Film 47 Ohms, 1/4w, 5% Carbon Film 47 Ohms, 1/4w, 5% Carboon Film 1Ok Ohms, 1/4w, 1% Metal Film 680 Ohms, 1/4w, 5% Carbon Film 10 Ohms, 2w, 5%, Metal Film 680 Ohms, 1/4w, 5% Carbon Film 2.2k Ohms,1/4w, 5% Carbon Film 5.1 k Ohms, 5w, 5% Wire Wound 22k Ohms,1/4w, 1% Metal Film 1 .Ok Ohms,1/4w, 5% Carbon Film 1.1kOhms, 1/4w, 1% Metal Film 22.1kOhms.1/4w, 1%Metal Film 10 Ohms, 2w, 5% Metal Film 27 Ohms, 1/4w, 5% CarbonFilm 47 Ohms, 1/4w, 5% Carbon Film 470 Ohms, 1/4w, 5% Carbon Film 10 Ohms,2w, 5% Metal Film 220 Ohms, 2w, 5% Metal Film 68 Ohms,1/4w, 5% Carbon Film 47 Ohms, 1/4w, 5% Carbon Film 10 Ohms, 2w, 5% Metal Film 10 Ohms, 2w, 5% Metal Film 30 Ohms,1/2w, 5% Carbon Film 2.7 Ohms, 1w, Metal Film 10 Ohms, 2w, 5% Metal Film 10 Ohms, 2w, 5% Metal Film 4.7kOhms, 1/2w, 5% Carbon Film 100kOhms, 1/4w, 1% Metal Film 12.1 Ohms, 1/4w, 1% Metal Film 10kOhms.1/4w. 1% Metal Film 33k Ohms,1/4w, 5% Carbon Film 1Ok Ohms,1/4w, 5% Carbon Film 33k Ohms,1/4w, 5% Carbon Film 5.11 k Ohms, 1/4w, 1% Metal Film 1 k Ohms, 1/4w, 1% Metal Film 22k Ohms, 1/4w, 5% Carbon Film PART NO. RMPl4-1101 RMPl4-2212 RCl4470 RCl4470 RMP/4-1 W2 RCl4-68 1 RM2-1 W tw4-681 RCl4-222 RWB5-SXZ RCi4-223 RCI4-102 RMPi4-1101 RMP/4-2212 RM2-1W RC/4-270 RCI4470 RCI4471 RM2-1 W RC/4-221 RCi4-680 RCi4470 RM2-1 W RM2-1 W ...