User Manual
Page 3
... beachten Sie bitte die folgenden Sicherheitshinweise: (German 5 CE Declaration of Conformity 6 ABOUT THE RA150/300/500 7 Principal Features 7 The Chassis 7 Inputs and Outputs 7 Amplifier topology 7 Protection Circuitry 7 About this manual 8 CONNECTIONS 9 Unpacking and Inspection 9 Power Considerations...Output Relays/Thermal Cycling 26 TROUBLESHOOTING 27 Troubleshooting Index 27 Care and Maintenance 28 Cleaning 28 Refer All Servicing to Alesis 28 Obtaining Repair Service 29 Customers outside the USA and Canada 29 SPECIFICATIONS 30 INDEX 34 ALESIS LIMITED WARRANTY 35 RA150...
... beachten Sie bitte die folgenden Sicherheitshinweise: (German 5 CE Declaration of Conformity 6 ABOUT THE RA150/300/500 7 Principal Features 7 The Chassis 7 Inputs and Outputs 7 Amplifier topology 7 Protection Circuitry 7 About this manual 8 CONNECTIONS 9 Unpacking and Inspection 9 Power Considerations...Output Relays/Thermal Cycling 26 TROUBLESHOOTING 27 Troubleshooting Index 27 Care and Maintenance 28 Cleaning 28 Refer All Servicing to Alesis 28 Obtaining Repair Service 29 Customers outside the USA and Canada 29 SPECIFICATIONS 30 INDEX 34 ALESIS LIMITED WARRANTY 35 RA150...
User Manual
Page 5
...an audiologist. PLEASE FOLLOW THESE PRECAUTIONS WHEN USING THIS PRODUCT: 1. Install in combination with an amplifier and headphones or speakers, may damage the front panel controls or cause a dangerous condition. ...convenience receptacles, and the point where they exit from peripheral equipment. 16. RA150/300/500 Reference Manual 3 Introduction/Safety Instructions IMPORTANT SAFETY INSTRUCTIONS SAFETY SYMBOLS USED...unused for long periods of time. 12. This symbol warns the user that output connectors contain voltages that can cause dangerous electrical shock. Do not install near ...
...an audiologist. PLEASE FOLLOW THESE PRECAUTIONS WHEN USING THIS PRODUCT: 1. Install in combination with an amplifier and headphones or speakers, may damage the front panel controls or cause a dangerous condition. ...convenience receptacles, and the point where they exit from peripheral equipment. 16. RA150/300/500 Reference Manual 3 Introduction/Safety Instructions IMPORTANT SAFETY INSTRUCTIONS SAFETY SYMBOLS USED...unused for long periods of time. 12. This symbol warns the user that output connectors contain voltages that can cause dangerous electrical shock. Do not install near ...
User Manual
Page 9
... overload. The Alesis models RA150, RA300, and RA500 provide extremely accurate sonic quality as well as measured specifications, but their conservative design and careful attention to electronic protection means they will activate the output relay and disconnect the loudspeaker load. For maximum reliability and low-noise operation the amplifiers use of an output fault, the...
... overload. The Alesis models RA150, RA300, and RA500 provide extremely accurate sonic quality as well as measured specifications, but their conservative design and careful attention to electronic protection means they will activate the output relay and disconnect the loudspeaker load. For maximum reliability and low-noise operation the amplifiers use of an output fault, the...
User Manual
Page 10
...1 Reference Series Features- • DC coupled, fully complementary discrete amplifier topology • Actively biased, dual differential input stages • Wide bandwidth, low distortion design • Fully protected from all fault conditions • LED output level metering (RA 300, RA 500) • Front panel ...1/4" & RCA single-ended input connectors • XLR input connectors (RA 300, RA 500) • Heavy-duty, dual binding post output connectors • Relay-controlled turn on/off • Silent, convection-cooled design • Heavy-duty steel chassis ABOUT THIS MANUAL In ...
...1 Reference Series Features- • DC coupled, fully complementary discrete amplifier topology • Actively biased, dual differential input stages • Wide bandwidth, low distortion design • Fully protected from all fault conditions • LED output level metering (RA 300, RA 500) • Front panel ...1/4" & RCA single-ended input connectors • XLR input connectors (RA 300, RA 500) • Heavy-duty, dual binding post output connectors • Relay-controlled turn on/off • Silent, convection-cooled design • Heavy-duty steel chassis ABOUT THIS MANUAL In ...
User Manual
Page 12
... driven, current consumption is capable of any amplifier will only sound good when connected to deliver its full rated output, both steady state and peak, with 120V power (as RA150/300/500 Reference Manual Long AC extension cables...consumption may also degrade the supply power. All fuses are the "Slo-Blo" type, sized at rated output: Model RA150 RA300 RA500 Rated AC consumption 270 watts 500 watts 840 watts Maximum (peak) 390 watts 650 watts 1080...watts or less. Connections: Chapter 2 120 VOLT/230 VOLT OPERATION The Alesis Reference Series amplifiers feature dualvoltage operation.
... driven, current consumption is capable of any amplifier will only sound good when connected to deliver its full rated output, both steady state and peak, with 120V power (as RA150/300/500 Reference Manual Long AC extension cables...consumption may also degrade the supply power. All fuses are the "Slo-Blo" type, sized at rated output: Model RA150 RA300 RA500 Rated AC consumption 270 watts 500 watts 840 watts Maximum (peak) 390 watts 650 watts 1080...watts or less. Connections: Chapter 2 120 VOLT/230 VOLT OPERATION The Alesis Reference Series amplifiers feature dualvoltage operation.
User Manual
Page 18
... the XLR type, most commonly sold as the Alesis Studio 32, feature balanced outputs on page 17.) To connect an unbalanced source to 1/4" TRS adapter. If your mixing console has XLR outputs, and you have an RA150 without an XLR input, then make a 1/4" mono to the amplifier input: Unbalanced cable Simply use an XLR-F to...
... the XLR type, most commonly sold as the Alesis Studio 32, feature balanced outputs on page 17.) To connect an unbalanced source to 1/4" TRS adapter. If your mixing console has XLR outputs, and you have an RA150 without an XLR input, then make a 1/4" mono to the amplifier input: Unbalanced cable Simply use an XLR-F to...
User Manual
Page 19
..., generates no inherent hum pickup, less expensive than transformers. Advantage of a 1/4" phone jack. The maximum number of amplifier channels will depend on the minimum output load impedance of the Alesis amplifiers is 600 Ω, up hum due to Channel A/Left only. For example, if the minimum... in parallel if desired. Active direct boxes use the amplifier in unbalanced configuration. Move the recessed slide switch under the right input connectors to the Channel B/Right input jack. RA150/300/500 Reference Manual 17 A line transformer can pick up to unbalanced...
..., generates no inherent hum pickup, less expensive than transformers. Advantage of a 1/4" phone jack. The maximum number of amplifier channels will depend on the minimum output load impedance of the Alesis amplifiers is 600 Ω, up hum due to Channel A/Left only. For example, if the minimum... in parallel if desired. Active direct boxes use the amplifier in unbalanced configuration. Move the recessed slide switch under the right input connectors to the Channel B/Right input jack. RA150/300/500 Reference Manual 17 A line transformer can pick up to unbalanced...
User Manual
Page 20
...several amps of installation. Connections: Chapter 2 OUTPUTS Warning: Be sure that the AC power is off their outputs until the low load condition is satisfactory. The RA150/300/500 amplifiers will not be damaged by excessively low output load impedances, but they lack sufficient current-...The table below the amplifier's rated output load. Because they will degrade the damping factor, efficiency and ultimately, the sound quality. the minimum acceptable wire type is the common "zip cord" used to connect AC to 18 gauge wire is removed. Alesis amplifiers can reliably drive ...
...several amps of installation. Connections: Chapter 2 OUTPUTS Warning: Be sure that the AC power is off their outputs until the low load condition is satisfactory. The RA150/300/500 amplifiers will not be damaged by excessively low output load impedances, but they lack sufficient current-...The table below the amplifier's rated output load. Because they will degrade the damping factor, efficiency and ultimately, the sound quality. the minimum acceptable wire type is the common "zip cord" used to connect AC to 18 gauge wire is removed. Alesis amplifiers can reliably drive ...
User Manual
Page 22
... units) "upstream" of correctly hooking up the output cables. Even though the same amount of air is 8 ohms, instead of using the RA150/300/500 as a stereo 2channel amplifier, it is reversed, the cone will suck air away from the RA150/300/500 input to speaker cone motion will ensure... that polarity reversal can cause phase-related problems such as a mono amplifier with respect to the Channel 1/Left...
... units) "upstream" of correctly hooking up the output cables. Even though the same amount of air is 8 ohms, instead of using the RA150/300/500 as a stereo 2channel amplifier, it is reversed, the cone will suck air away from the RA150/300/500 input to speaker cone motion will ensure... that polarity reversal can cause phase-related problems such as a mono amplifier with respect to the Channel 1/Left...
User Manual
Page 23
...) when making input or output connections to the speakers. MUTE SWITCH Because turning the RA150/300/500 on power just in the system will light. RA150/300/500 Reference Manual 21 Power should not be off generates no spikes within the amplifier, the power switch doubles...should be a problem. Chapter 3: Operation CHAPTER 3 OPERATION ON-OFF SWITCH Press the switch to turn the amplifier on, and again to turn off . However, the RA150/300/500's output protection relays have a 4.5 second turn-on delay which keeps the loudspeakers disconnected while the system is usually...
...) when making input or output connections to the speakers. MUTE SWITCH Because turning the RA150/300/500 on power just in the system will light. RA150/300/500 Reference Manual 21 Power should not be off generates no spikes within the amplifier, the power switch doubles...should be a problem. Chapter 3: Operation CHAPTER 3 OPERATION ON-OFF SWITCH Press the switch to turn the amplifier on, and again to turn off . However, the RA150/300/500's output protection relays have a 4.5 second turn-on delay which keeps the loudspeakers disconnected while the system is usually...
User Manual
Page 24
... for proper polarity. However, if the LEDs flash often or remain on while the output relay is connected. • When the thermal protection circuitry is activated because the amplifier is at maximum output, at the onset of the speaker cone movement. If the speaker cables are not mislabelled... Make sure this switch converts the RA150/300/500 from the loudspeaker as you connect the battery, and another as possible, you disconnect it is operating 33 dB or less below rated output. No LEDs will stop automatically when the amplifier cools down the volume controls to reduce...
... for proper polarity. However, if the LEDs flash often or remain on while the output relay is connected. • When the thermal protection circuitry is activated because the amplifier is at maximum output, at the onset of the speaker cone movement. If the speaker cables are not mislabelled... Make sure this switch converts the RA150/300/500 from the loudspeaker as you connect the battery, and another as possible, you disconnect it is operating 33 dB or less below rated output. No LEDs will stop automatically when the amplifier cools down the volume controls to reduce...
User Manual
Page 25
.../500 "Reference Amplifier" excels in parallel to speakers is possible. This will be able to high-power applications. Near-field monitors offer other advantages compared to large studio speakers, including smaller size, lower cost, and easier transportability to other abuse of the RA150/300/500, damage to the output of the headphone send...
.../500 "Reference Amplifier" excels in parallel to speakers is possible. This will be able to high-power applications. Near-field monitors offer other advantages compared to large studio speakers, including smaller size, lower cost, and easier transportability to other abuse of the RA150/300/500, damage to the output of the headphone send...
User Manual
Page 27
... distorting the speakers unless you turn the power off and locate the source of the RA150/300/500 must be turned down to avoid amplifier clipping. Most mixers output +4 dBu at nominal levels, increase the test tone until the desired peak sound pressure level is applied, slowly ... the amp will keep the gain of the mixer output stage or wiring unnecessarily. The input sensitivity of noisy operation, especially in a multi-amplified system is -10 dBV (.316 volts). Set the mixer's controls at nominal level/0 VU; RA150/300/500 Reference Manual 25 The mixer's meter should...
... distorting the speakers unless you turn the power off and locate the source of the RA150/300/500 must be turned down to avoid amplifier clipping. Most mixers output +4 dBu at nominal levels, increase the test tone until the desired peak sound pressure level is applied, slowly ... the amp will keep the gain of the mixer output stage or wiring unnecessarily. The input sensitivity of noisy operation, especially in a multi-amplified system is -10 dBV (.316 volts). Set the mixer's controls at nominal level/0 VU; RA150/300/500 Reference Manual 25 The mixer's meter should...
User Manual
Page 28
... or excessively low line voltage. Overheating is overloaded. OUTPUT RELAYS/THERMAL CYCLING Reference Series amplifiers have high-current output protection relays which will glow. Operation: Chapter 3 Amplifier input clipping On the other hand, the maximum level at the amplifier can receive a supply of cooler air. 26 RA150/300/500 Reference Manual It is possible that the...
... or excessively low line voltage. Overheating is overloaded. OUTPUT RELAYS/THERMAL CYCLING Reference Series amplifiers have high-current output protection relays which will glow. Operation: Chapter 3 Amplifier input clipping On the other hand, the maximum level at the amplifier can receive a supply of cooler air. 26 RA150/300/500 Reference Manual It is possible that the...
User Manual
Page 29
...) Power is not connected Line voltage set improperly Amplifier accidentally set to the "stereo" position Make sure that the RA150/300/500 and its internal temperature has dropped to locate possible causes and solutions before contacting Alesis Product Support for stereo Input cables are crossing a... controls, there are required for a coffee break. use the following table to reliable levels. Aside from outputs Cause No input audio Bad cables Amplifier is confirmed, no special considerations are no user adjustments or routine maintenance operations necessary (or available).
...) Power is not connected Line voltage set improperly Amplifier accidentally set to the "stereo" position Make sure that the RA150/300/500 and its internal temperature has dropped to locate possible causes and solutions before contacting Alesis Product Support for stereo Input cables are crossing a... controls, there are required for a coffee break. use the following table to reliable levels. Aside from outputs Cause No input audio Bad cables Amplifier is confirmed, no special considerations are no user adjustments or routine maintenance operations necessary (or available).
User Manual
Page 30
...activated Shut off power and let amplifier cool down Defective loudspeaker drivers Replace drivers In a multi-amplified system with a low level crossover network, bad outputs from the network, or improperly connected loudspeakers Balanced connector with one of the best amplifiers that the RA150/300/500 is one side disconnected...and then returns, the amplifier may be performed only by qualified technicians. DO NOT SPRAY THE CLEANER DIRECTLY ONTO THE FRONT OF THE UNIT AS IT MAY DESTROY THE LUBRICANTS USED IN THE SWITCHES AND CONTROLS! REFER ALL SERVICING TO ALESIS We believe that can be...
...activated Shut off power and let amplifier cool down Defective loudspeaker drivers Replace drivers In a multi-amplified system with a low level crossover network, bad outputs from the network, or improperly connected loudspeakers Balanced connector with one of the best amplifiers that the RA150/300/500 is one side disconnected...and then returns, the amplifier may be performed only by qualified technicians. DO NOT SPRAY THE CLEANER DIRECTLY ONTO THE FRONT OF THE UNIT AS IT MAY DESTROY THE LUBRICANTS USED IN THE SWITCHES AND CONTROLS! REFER ALL SERVICING TO ALESIS We believe that can be...
User Manual
Page 35
...be convection-type only, with an on the back panel shall allow the user to automatically null DC output voltage offsets. The power output of the amplifier shall be 75 watts per channel (RA150), 150 watts per channel (RA300) or 250 watts per channel (RA500) into an 8-ohm load ... controls capable of delivering full rated power at full clockwise rotation with no fan mounted inside the amplifier. The input connectors shall be an Alesis RA150/300/500 Reference Series power amplifier. 33 All components shall be of high quality and mechanical construction and optimized for excessive DC offset...
...be convection-type only, with an on the back panel shall allow the user to automatically null DC output voltage offsets. The power output of the amplifier shall be 75 watts per channel (RA150), 150 watts per channel (RA300) or 250 watts per channel (RA500) into an 8-ohm load ... controls capable of delivering full rated power at full clockwise rotation with no fan mounted inside the amplifier. The input connectors shall be an Alesis RA150/300/500 Reference Series power amplifier. 33 All components shall be of high quality and mechanical construction and optimized for excessive DC offset...
User Manual
Page 36
...direct box, 17 Fuse, 10 gain setting, 25 ground audio, 9, 14 ground lifter, 24 ground loop, 24 grounding, 3 headphone amplifiers, 23 heat sink, 11 high-temperature operation, 11 impedance input, 17 speaker, 18 input clipping, 26 Inputs, 13 magnetic fields,... 12 Maintenance, 28 Meters, 22 Mono. See Bridged Mono noise, 25 Output Relays, 26 Outputs, 18 INDEX phase. See Repair Service, 29 Safety, 3, 24 shield telescoping, 24 sound level meter, 25 Specifications... 9 volume controls, 21 XLR input, 16 XLR input jacks, 13 34 RA150/300/500 Reference Manual
...direct box, 17 Fuse, 10 gain setting, 25 ground audio, 9, 14 ground lifter, 24 ground loop, 24 grounding, 3 headphone amplifiers, 23 heat sink, 11 high-temperature operation, 11 impedance input, 17 speaker, 18 input clipping, 26 Inputs, 13 magnetic fields,... 12 Maintenance, 28 Meters, 22 Mono. See Bridged Mono noise, 25 Output Relays, 26 Outputs, 18 INDEX phase. See Repair Service, 29 Safety, 3, 24 shield telescoping, 24 sound level meter, 25 Specifications... 9 volume controls, 21 XLR input, 16 XLR input jacks, 13 34 RA150/300/500 Reference Manual