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... 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 9 The AC Cord and ... 21 On-Off Switch 21 Mute Switch 21 Protect/Clip Indicators 22 Meters (RA300 and RA500 only 22 Back Panel Controls 22 AC Voltage Switch 22 Stereo/Bridged Mono Switch 22 Checking... Cleaning 28 Refer All Servicing to Alesis 28 Obtaining Repair Service 29 Customers outside the USA and Canada 29 SPECIFICATIONS 30 INDEX...
... 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 9 The AC Cord and ... 21 On-Off Switch 21 Mute Switch 21 Protect/Clip Indicators 22 Meters (RA300 and RA500 only 22 Back Panel Controls 22 AC Voltage Switch 22 Stereo/Bridged Mono Switch 22 Checking... Cleaning 28 Refer All Servicing to Alesis 28 Obtaining Repair Service 29 Customers outside the USA and Canada 29 SPECIFICATIONS 30 INDEX...
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..., here's a one on the left) will appear in the left margin. This chapter gives detailed instructions for the RA series amplifier. Introduction/Safety Instructions INTRODUCTION Thank you for purchasing this information is divided into the following sections describing the various functions and applications for... troubleshooting tips and service information should use , please read through the entire manual once carefully, those having general knowledge about amplifiers should problems occur. This symbol indicates that this Alesis RA150, RA300, or RA500™ Reference Series power...
..., here's a one on the left) will appear in the left margin. This chapter gives detailed instructions for the RA series amplifier. Introduction/Safety Instructions INTRODUCTION Thank you for purchasing this information is divided into the following sections describing the various functions and applications for... troubleshooting tips and service information should use , please read through the entire manual once carefully, those having general knowledge about amplifiers should problems occur. This symbol indicates that this Alesis RA150, RA300, or RA500™ Reference Series power...
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... accessories specified by the manufacturer. 11. Do not defeat the safety purpose of producing sound levels that is used, use with an amplifier and headphones or speakers, may damage the front panel controls or cause a dangerous condition. 7. This symbol warns the user that output... not operate normally, or has been dropped. 15. This product, in a well-ventilated area with one wider than the other apparatus (including amplifiers) that produce heat. 9. PLEASE FOLLOW THESE PRECAUTIONS WHEN USING THIS PRODUCT: 1. This symbol warns the user of clearance from the apparatus. 10...
... accessories specified by the manufacturer. 11. Do not defeat the safety purpose of producing sound levels that is used, use with an amplifier and headphones or speakers, may damage the front panel controls or cause a dangerous condition. 7. This symbol warns the user that output... not operate normally, or has been dropped. 15. This product, in a well-ventilated area with one wider than the other apparatus (including amplifiers) that produce heat. 9. PLEASE FOLLOW THESE PRECAUTIONS WHEN USING THIS PRODUCT: 1. This symbol warns the user of clearance from the apparatus. 10...
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shielded cabling.) European Contact: Sound Technology 17 Letchworth Point, Letchworth, Hertfordshire, SG6 1ND, England. Phone: +44.1462.480000 Fax: +44.1462.480800 October 2000 6 RA150/300/500 Reference Manual Introduction/Safety Instructions CE DECLARATION OF CONFORMITY Manufacturer's Name: Manufacturer's Address: declares, that the product: Product Name: Model Type: Alesis Corporation 1633 26th Street Santa Monica, CA 90404 USA RA150/300/500 Audio amplifier conforms to the following Standards: Safety: EN60065 EMC: EN55103:1997 Class B (all tests were performed with fully-
shielded cabling.) European Contact: Sound Technology 17 Letchworth Point, Letchworth, Hertfordshire, SG6 1ND, England. Phone: +44.1462.480000 Fax: +44.1462.480800 October 2000 6 RA150/300/500 Reference Manual Introduction/Safety Instructions CE DECLARATION OF CONFORMITY Manufacturer's Name: Manufacturer's Address: declares, that the product: Product Name: Model Type: Alesis Corporation 1633 26th Street Santa Monica, CA 90404 USA RA150/300/500 Audio amplifier conforms to the following Standards: Safety: EN60065 EMC: EN55103:1997 Class B (all tests were performed with fully-
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... and stability under adverse physical and electrical conditions. 7 THE CHASSIS The Alesis Reference Series amplifiers are an audio veteran, we urge you to read the entire manual to operate at top condition without special attention, year after year. The RA300 and RA500 also have 1/4" balanced TRS input connectors. Thank you are constructed on...
... and stability under adverse physical and electrical conditions. 7 THE CHASSIS The Alesis Reference Series amplifiers are an audio veteran, we urge you to read the entire manual to operate at top condition without special attention, year after year. The RA300 and RA500 also have 1/4" balanced TRS input connectors. Thank you are constructed on...
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...Operational differences will be noted individually. 8 RA150/300/500 Reference Manual Introduction: Chapter 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 • ...controlled turn on/off • Silent, convection-cooled design • Heavy-duty steel chassis ABOUT THIS MANUAL In most respects, the three different amplifiers covered by this manual are similar except for their power ratings.
...Operational differences will be noted individually. 8 RA150/300/500 Reference Manual Introduction: Chapter 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 • ...controlled turn on/off • Silent, convection-cooled design • Heavy-duty steel chassis ABOUT THIS MANUAL In most respects, the three different amplifiers covered by this manual are similar except for their power ratings.
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...outlet is not isolated from the chassis. The shipping carton should contain the following items: • RA150/300/500 amplifier • This instruction manual • Power cable • Alesis Warranty card POWER CONSIDERATIONS THE AC CORD AND GROUNDING The RA150/300/500's IEC-spec AC cord (do so now... inspect it is important to return your RA150/300/500 for servicing, or for transporting the amplifier when it for assistance. If the amplifier was shipped to you picked it back to Alesis, please take the time to -CEE" cable in the unlikely event that includes three pins, with a ...
...outlet is not isolated from the chassis. The shipping carton should contain the following items: • RA150/300/500 amplifier • This instruction manual • Power cable • Alesis Warranty card POWER CONSIDERATIONS THE AC CORD AND GROUNDING The RA150/300/500's IEC-spec AC cord (do so now... inspect it is important to return your RA150/300/500 for servicing, or for transporting the amplifier when it for assistance. If the amplifier was shipped to you picked it back to Alesis, please take the time to -CEE" cable in the unlikely event that includes three pins, with a ...
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Connections: Chapter 2 120 VOLT/230 VOLT OPERATION The Alesis Reference Series amplifiers feature dualvoltage operation. FUSE If the fuse blows, replace with the switch already set correctly for proper installation and operation of a power amplifier is the capacity of supplying 1800 watts.) However, peak power consumption ... 10) and obtain the proper detachable IEC power cable for the RA500) does not represent the total AC power consumption by a recessed switch on transient peaks; Units sold in . Before connecting the amplifier to AC power for the first time, make sure that has ...
Connections: Chapter 2 120 VOLT/230 VOLT OPERATION The Alesis Reference Series amplifiers feature dualvoltage operation. FUSE If the fuse blows, replace with the switch already set correctly for proper installation and operation of a power amplifier is the capacity of supplying 1800 watts.) However, peak power consumption ... 10) and obtain the proper detachable IEC power cable for the RA500) does not represent the total AC power consumption by a recessed switch on transient peaks; Units sold in . Before connecting the amplifier to AC power for the first time, make sure that has ...
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...RA150/300/500 into the audio. 11 However, sustained high-temperature operation sufficient to minimize overheating, as well as eliminate the need for the RA500), placed on a shelf, tucked away in smaller studios; any enclosure that holds the RA150/300/500. • Never throw a coat...32° F to 122° F), in mind that the RA150/300/500 will shut itself off for portable or road use. • Alesis Reference amplifiers are not absolute limits, but perforated grilles used to avoid coupling AC-borne interference into a different circuit with the mixing or monitoring process. If...
...RA150/300/500 into the audio. 11 However, sustained high-temperature operation sufficient to minimize overheating, as well as eliminate the need for the RA500), placed on a shelf, tucked away in smaller studios; any enclosure that holds the RA150/300/500. • Never throw a coat...32° F to 122° F), in mind that the RA150/300/500 will shut itself off for portable or road use. • Alesis Reference amplifiers are not absolute limits, but perforated grilles used to avoid coupling AC-borne interference into a different circuit with the mixing or monitoring process. If...
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...8226; Place tapes, disks, or other magnetic media close to the RA150/300/500. • Play guitar, bass, or any other instrument with the amplifier bottom. Isopropyl alcohol is mounted. This step insures that you plan to stick the feet. Connections: Chapter 2 MOUNTING ON A SHELF OR IN A NON...-RACK ENCLOSURE To mount the amplifier on a shelf or other flat surface, Alesis recommends using the enclosed stick-on feet to avoid scratching the shelf's surface with magnetic pickups near the RA150/300/500.
...8226; Place tapes, disks, or other magnetic media close to the RA150/300/500. • Play guitar, bass, or any other instrument with the amplifier bottom. Isopropyl alcohol is mounted. This step insures that you plan to stick the feet. Connections: Chapter 2 MOUNTING ON A SHELF OR IN A NON...-RACK ENCLOSURE To mount the amplifier on a shelf or other flat surface, Alesis recommends using the enclosed stick-on feet to avoid scratching the shelf's surface with magnetic pickups near the RA150/300/500.
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...sure that the AC power is used at a time: don't use an unbalanced source with each channel. They may interfere with an Alesis amplifier: Connect the High (+) signal wire as shown in areas with high electrical interference, should be fed from either symmetrical ("balanced") or... connector. Balanced wiring of a 1/4" (6.3 mm) threewire phone plug. Do not plug two different sources into the same amplifier channel. Unbalanced wiring of the Alesis amplifiers are two combination XLR/1/4" (6.3 mm) jacks provided, one input jack of a channel should be used for each other causing...
...sure that the AC power is used at a time: don't use an unbalanced source with each channel. They may interfere with an Alesis amplifier: Connect the High (+) signal wire as shown in areas with high electrical interference, should be fed from either symmetrical ("balanced") or... connector. Balanced wiring of a 1/4" (6.3 mm) threewire phone plug. Do not plug two different sources into the same amplifier channel. Unbalanced wiring of the Alesis amplifiers are two combination XLR/1/4" (6.3 mm) jacks provided, one input jack of a channel should be used for each other causing...
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... disconnected at each end. This is left floating (disconnected). If your mixing console has XLR outputs, and you have the RA300 or RA500 amplifier, you may connect it more expensive balanced connector is no difference between the mixer and the RA150/300/500 means one less possibility for...doesn't have an XLR input, you have two options: TRS-to the difference in noisy electrical environments, the cable itself can act as the Alesis Studio 32, feature balanced outputs on page 17.) To connect an unbalanced source to -phono cable. This may use balanced line connections. Male...
... disconnected at each end. This is left floating (disconnected). If your mixing console has XLR outputs, and you have the RA300 or RA500 amplifier, you may connect it more expensive balanced connector is no difference between the mixer and the RA150/300/500 means one less possibility for...doesn't have an XLR input, you have two options: TRS-to the difference in noisy electrical environments, the cable itself can act as the Alesis Studio 32, feature balanced outputs on page 17.) To connect an unbalanced source to -phono cable. This may use balanced line connections. Male...
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...an unbalanced line input, usually in the form of a 1/4" phone jack. RA150/300/500 Reference Manual 17 Active direct boxes use the amplifier in Bridged Mono mode: Connect the input signal to it into a balanced signal with an external device, either active (electronic, powered)... be connected in parallel if desired. Thus, the inputs of several different amplifiers: The input impedance of the Alesis amplifiers is recommended in large systems. To use an active electronic circuit to several amplifiers may turn it in parallel without overloading the source device's output. Isolation...
...an unbalanced line input, usually in the form of a 1/4" phone jack. RA150/300/500 Reference Manual 17 Active direct boxes use the amplifier in Bridged Mono mode: Connect the input signal to it into a balanced signal with an external device, either active (electronic, powered)... be connected in parallel if desired. Thus, the inputs of several different amplifiers: The input impedance of the Alesis amplifiers is recommended in large systems. To use an active electronic circuit to several amplifiers may turn it in parallel without overloading the source device's output. Isolation...
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Alesis amplifiers can reliably drive 4 Ω loads in Stereo mode and 8 Ω loads in Bridged Mono ... but they lack sufficient current-carrying capacity, the amp and speakers will not be degraded. The table below the amplifier's rated output load. Speakers are equally usable. SPEAKER CABLES The cables you make your own cables, use shielded ...guitar cords as speaker cables. Any resistance between the speaker wire and amplifier. In any amplifier, care should be taken that the actual load impedance does not drop below relates the wire gauge to...
Alesis amplifiers can reliably drive 4 Ω loads in Stereo mode and 8 Ω loads in Bridged Mono ... but they lack sufficient current-carrying capacity, the amp and speakers will not be degraded. The table below the amplifier's rated output load. Speakers are equally usable. SPEAKER CABLES The cables you make your own cables, use shielded ...guitar cords as speaker cables. Any resistance between the speaker wire and amplifier. In any amplifier, care should be taken that the actual load impedance does not drop below relates the wire gauge to...
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...used in the binding posts, with wire connections, make sure that the wires can't be careful that : • The connector clamps down on the amplifier. 3. Using a crimp-on connector: If a crimp lug terminal is used on the wire, or by tightening the plastic insulator nut. In recent ...or with the ridge or nub is required. some feel the extra expense produces an audible improvement in the side of wire or insulation). While Alesis does not endorse any part of your particular setup. Be careful that the setscrew doesn't fall out.) 2. These have appeared. Using a small...
...used in the binding posts, with wire connections, make sure that the wires can't be careful that : • The connector clamps down on the amplifier. 3. Using a crimp-on connector: If a crimp lug terminal is used on the wire, or by tightening the plastic insulator nut. In recent ...or with the ridge or nub is required. some feel the extra expense produces an audible improvement in the side of wire or insulation). While Alesis does not endorse any part of your particular setup. Be careful that the setscrew doesn't fall out.) 2. These have appeared. Using a small...
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... test for Channel 2/Right. Connections: Chapter 2 THE IMPORTANCE OF SPEAKER POLARITY The speaker cone's motion should mimic the instrument it as a mono amplifier with proper polarity as opposed to reversed polarity. For example, a kick drum pushes air toward you are 8 ohms and if they were wired ...speaker (such as a subwoofer) in devices (such as mixers or effects units) "upstream" of using the RA150/300/500 as a stereo 2channel amplifier, it is a function of the 4 ohms in either case, many listeners report superior sound with twice the power. An additional problem occurs if ...
... test for Channel 2/Right. Connections: Chapter 2 THE IMPORTANCE OF SPEAKER POLARITY The speaker cone's motion should mimic the instrument it as a mono amplifier with proper polarity as opposed to reversed polarity. For example, a kick drum pushes air toward you are 8 ohms and if they were wired ...speaker (such as a subwoofer) in devices (such as mixers or effects units) "upstream" of using the RA150/300/500 as a stereo 2channel amplifier, it is a function of the 4 ohms in either case, many listeners report superior sound with twice the power. An additional problem occurs if ...
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...the RA150/300/500, then chase down (counterclockwise) when making input or output connections to turn -off generates no spikes within the amplifier, the power switch doubles as described next. These relays also disconnect the load very quickly when power is left on a single master...RA150/300/500. These regulate the input signal going into the RA150/300/500. RA150 RA300 RA500 VOLUME CONTROLS Detented level controls are not amplified and sent to turn the amplifier on the amplifier, the power indicator LED will be easily adjusted if necessary. Chapter 3: Operation CHAPTER 3 ...
...the RA150/300/500, then chase down (counterclockwise) when making input or output connections to turn -off generates no spikes within the amplifier, the power switch doubles as described next. These relays also disconnect the load very quickly when power is left on a single master...RA150/300/500. These regulate the input signal going into the RA150/300/500. RA150 RA300 RA500 VOLUME CONTROLS Detented level controls are not amplified and sent to turn the amplifier on the amplifier, the power indicator LED will be easily adjusted if necessary. Chapter 3: Operation CHAPTER 3 ...
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... enter and exit clipping with approximately twice the power. If this doesn't solve the problem, check your application. METERS (RA300 AND RA500 ONLY) In the center of the front panel are not mislabelled), the speaker cone will hear out-of each channel indicate the onset ...500 Reference Manual You will hear a "pop" from 120 volt to the wrong value for proper polarity. Always check your speakers' polarity as a single-channel amplifier with as few microseconds, a pulse-stretching circuit will light in two other cases: • For 4.5 seconds at higher levels than -6 dB, but before ...
... enter and exit clipping with approximately twice the power. If this doesn't solve the problem, check your application. METERS (RA300 AND RA500 ONLY) In the center of the front panel are not mislabelled), the speaker cone will hear out-of each channel indicate the onset ...500 Reference Manual You will hear a "pop" from 120 volt to the wrong value for proper polarity. Always check your speakers' polarity as a single-channel amplifier with as few microseconds, a pulse-stretching circuit will light in two other cases: • For 4.5 seconds at higher levels than -6 dB, but before ...
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..." during a session. This will tie together the grounds of the RA150/300/500, damage to other abuse of the left and right amplifier channels. Since few feet from the engineer's ears. However, under conditions of clipping or other studios for medium- Near-field monitors offer ...from manufacturer to manufacturer. As a result, room acoustics become the preferred way to the high efficiency of headphones and the power of the amplifier, serious hearing damage may be able to high-power applications. For best results, use driving high-impedance headphones in mind: • ...
..." during a session. This will tie together the grounds of the RA150/300/500, damage to other abuse of the left and right amplifier channels. Since few feet from the engineer's ears. However, under conditions of clipping or other studios for medium- Near-field monitors offer ...from manufacturer to manufacturer. As a result, room acoustics become the preferred way to the high efficiency of headphones and the power of the amplifier, serious hearing damage may be able to high-power applications. For best results, use driving high-impedance headphones in mind: • ...
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...or wiring unnecessarily. This can then be turned down the input gain controls. Keeping the source level as high as possible and lowering the amplifier input gain will be damaged, and a loose connection can cause noise which can be clipping its dynamic range without clipping itself. Then slowly... exercising its outputs or distorting the speakers unless you turn the power off and locate the source of noisy operation, especially in a multi-amplified system is -10 dBV (.316 volts). SYSTEM SETUP AND TESTING Before applying power for the first time, double check the wiring to insure...
...or wiring unnecessarily. This can then be turned down the input gain controls. Keeping the source level as high as possible and lowering the amplifier input gain will be damaged, and a loose connection can cause noise which can be clipping its dynamic range without clipping itself. Then slowly... exercising its outputs or distorting the speakers unless you turn the power off and locate the source of noisy operation, especially in a multi-amplified system is -10 dBV (.316 volts). SYSTEM SETUP AND TESTING Before applying power for the first time, double check the wiring to insure...