6125A 4200A Multi-channel power amplifiers Professional Altec Lansing Professional 1000 W. Wilshire Blvd. Suite 362 Oklahoma City, OK 73116 USA A division of Altec Lansing Technologies Inc, Milford PA 18337-0277 Made In USA Operating Manual 6125A and 4200A Multi-Channel Power Amplifier Table Of Contents 1 2 3 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 UNPACKING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 AC 3.1 3.2 3.3 POWER REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Voltage Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Current Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AC Grounding & Earth Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4 4 5 4 CABLE REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.1 Input Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.2 Output Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 RACK-MOUNTING REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1 Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 5 5 5 5 6 7 FRONT PANEL FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 REAR PANEL FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1 Input Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2 Input Ground Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3 Multi-Channel Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4 50Hz Low Cut Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 Input Level Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6 Stereo/Mono Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7 Dual Channel Mode/Bridge Mode Switches . . . . . . . . . . . . . . . . . . . . . . 7.8 Loudspeaker Output Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9 AC Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7 7 7 8 8 8 8 9 9 8 SELF-PROTECTION FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 8.1 Power Supply Undervoltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 8.2 Power Supply Overvoltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 8.3 Output Overcurrent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 8.4 Heat Sink Overtemperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 8.5 Unacceptable DC or High Frequency Output Content . . . . . . . . . . . . 10 8.6 AC Power Interruption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 TYPICAL APPLICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.1 Six Channel Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2 Dual Mono Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.3 Bridged Mono Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.4 Typical PA Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 11 11 12 12 9 2 Operating Manual 6125A and 4200A Multi-Channel Power Amplifier 10 DESIGN THEORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 11 TROUBLESHOOTING TIPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 No Audio Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Distorted Sound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3 Hum or Buzz Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 13 14 14 12 DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 13 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 14 WARRANTY INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Caution: produce dangerous This power amplifier can produce dangerous output voltage levels, high re order pre power levels, and high sound pre s s u re levels in loudspeakers. In order to miniinjury, read entire owner's mize the risk of injury, damage, or hearing loss, please read the entire owner's before manual before connecting to a sound system. CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN The lightning flash with arrowhead symbol, within an equalateral triangle, is intended to alert the user to the presence of uninsulated "dangerous voltage" within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. The exclamation point within an equalateral triangle is intended to alert the user to the presence of important operating and maintenance instructions in the literature accompanying the device. TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE COVER. NO USER SERPA RTS SERVICING SERVICE VICEABLE PA RTS INSIDE. REFER SER VICING TO QUALIFIED SERVICE PERSONNEL. TO REDUCE THE RISK OF FIRE OR ELECTRICAL SHOCK, DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE. ONLY TO REDUCE THE RISK OF FIRE, REPLACE ONLY WITH SAME TYPE FUSE. SERVICE REFER REPLACEMENT TO QUALIFIED SER VICE PERSONNEL. APPA ATUS EARTHED WARNING: THIS APPA R ATUS MUST BE EARTHED THROUGH THE SUPPLIED POWER LINE CORD 3 Operating Manual 6125A and 4200A Multi-Channel Power Amplifier 1. INTRODUCTION The right to any claim against a public carrier can be forfeited if the carrier is not notified promptly and if the shipping carton and packing materials are not available for inspection by the carrier. Save all packing materials until the claim has been settled. 3. AC POWER REQUIREMENTS 3.1 Although similar to other amplifiers with class D output stages, the 6125A and 4200A amplifiers employ internal microprocessor and DSP algorithms to optimize output switching characteristics and eliminate the usual harshness associated with high-frequency audio in standard class D amplifiers. This optimization results in a spread-spectrum switched output that varies with input amplitude and frequency, and minimizes radiated emissions by eliminating the single-frequency high-energy radiated interference normally associated with switching outputs. The use of a simple linear power supply removes another potential source of radio-frequency interference, an important consideration as racks become more and more heavily populated with digital signal processing equipment. A small switching supply using flyback topology provides an efficient power source for logic, protection, pre-amplifier and indicator circuits. To assure reliable operation, the usual protection from excessive high-frequency, DC offset, and thermal overload is supplemented by power supply undervoltage, power supply overvoltage, and output overcurrent detection, all monitored and controlled by the latest in miniaturized microprocessor technology. In sum, 6125A and 4200A amplifiers combine the best of the new digital technologies with the best of the traditional analog technologies to provide a product that will supply clean sound at full output from every channel while generating minimal heat, thus increasing the reliability of every other piece of equipment in a rack as well as preserving its own. 2. UNPACKING Voltage Requirements The 6125A and 4200A power amplifiers combine the efficiency of a MOSFET high-speed switching output stage with the sophistication of modern microprocessor and DSP technology to produce a multi-channel amplifier with unprecedented versatility and power in a single 3RU package. The 6125A and 4200A amplifiers can be operated from nominal 120VAC or 240VAC, 50/60Hz mains. This is user-configurable by changing the insert in the AC Inlet (See section 7.9). The power connector on the amplifier accepts a standard IEC-320 receptacle. For nominal 120VAC operation, the power cord should be three-conductor, rated for at least 13A (16AWG). The line fuse should be type MDA, 12A. For nominal 240VAC operation, the power cord should be three-conductor, rated for at least 10A (18AWG). The line fuse should be type MDA, 10A. 3.2 Current Requirements 1.) Idle (no audio): 6125A 120V: 0.81A 240V: 0.42A 2.) With typical audio inputs: 8 loads on all channels 120V: 4A 240V: 2A 4 loads on all channels 120V: 6.5A 240V: 3.3A 4200A 120V: 0.9A 240V: 0.5A 120V: 4.6A 240V: 2.3A 120V: 7.0A 240V: 3.5A As a part of our system of quality control, every Altec Lansing product is carefully inspected before leaving the factory to ensure flawless appearance. After unpacking, please inspect for any physical damage. Save the shipping carton and all packing materials, as they were carefully designed to reduce to minimum the possibility of transportation damage should the unit again require packing and shipping. In the event that damage has occurred, immediately notify your dealer so that a written claim to cover the damages can be initiated. 6125A and 4200A amplifiers consume less than 12 amps when all channels operate at 1/8 power into rated (4 ohm) loads. This condition satisfies the UL, CSA and building electrical code requirements for a piece of audio equipment not to consume more than 80% of the current available when plugged into a grounded 15 amp outlet and operated at 1/8 of maximum power. 3.3 AC Grounding and Earth Grounding To reduce the risk of ground loop hum, all system ground references should originate at the same point in your AC power distribution. Do not remove the amplifier's ground pin, as it creates a potential shock hazard. 4 Operating Manual 6125A and 4200A Multi-Channel Power Amplifier 4. CABLE REQUIREMENTS 5. RACK-MOUNTING REQUIREMENTS 4.1 Input Cables Be sure to use shielded cable whether balanced or unbalanced. Shielding which is properly grounded will protect the signal from outside electrical interference such as RF, fluorescent lighting, and computer/display emissions. As a general rule, unbalanced or single-ended (tipsleeve) lines of less than 10 feet are satisfactory, but greater distances or noisy field environments require a balanced signal. Avoid running input lines in close proximity or parallel to long speaker lines, AC power cables, or power transformers, as this may generate hum or oscillation. 4.2 Output Cables These amplifiers are capable of delivering high levels of output current, therefore the wire gauge used for speaker cables is particularly important. Inadequate wire gauge can add significant resistance to the speaker's own impedance, especially over long distances, reducing the power which is actually delivered to the speaker. It could also result in a decreased damping factor and possible fire hazard. Since power at the speaker load is of primary concern in system design, we have included a table to best determine appropriate wire gauge for your application. The following table lists the resistance per 100 feet of common copper wire gauges, and also gives the percentage of the speaker load power which would be lost in an arbitrary 100 ft run of different gauges of 2-conductor copper speaker wire. Wire Gauge /100ft #8 #10 #12 #14 #16 #18 .0605 .1018 .1619 .2575 .4094 .6510 8 load 0.8% 1.3% 2.0% 3.2% 5.1% 8.1% 4 load 1.5% 2.5% 4.0% 6.4% 10.2% 16.3% 5.1 Mechanical The 6125A and 4200A amplifiers are designed to fit in standard 19-inch equipment racks. The front panel rack-mount ears are sufficiently strong for most applications, however if you desire further integrity for mobile racks, we recommend using the four additional holes in the back of the chassis for supplemental rear-mounting (see dimensional drawing for details). 5.2 Cooling Be certain that both the front and back of the rack have unhindered acces ...