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...OPERATION 21 Front Panel Controls 21 Volume Controls 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 For Proper Polarity 22 Using the RA150... as a Headphone Amplifier.......23 Choosing the Correct Speakers 23 About Ground Loops 24 System Setup and Testing 25 Setting the Gain Properly 25 Output Relays/Thermal Cycling 26 TROUBLESHOOTING 27 Troubleshooting Index 27 Care and Maintenance 28 Cleaning 28 Refer All Servicing to Alesis 28 Obtaining Repair ...
...OPERATION 21 Front Panel Controls 21 Volume Controls 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 For Proper Polarity 22 Using the RA150... as a Headphone Amplifier.......23 Choosing the Correct Speakers 23 About Ground Loops 24 System Setup and Testing 25 Setting the Gain Properly 25 Output Relays/Thermal Cycling 26 TROUBLESHOOTING 27 Troubleshooting Index 27 Care and Maintenance 28 Cleaning 28 Refer All Servicing to Alesis 28 Obtaining Repair ...
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.... This section explains how to a variety of contents to read this Alesis RA150, RA300, or RA500™ Reference Series power amplifier. This chapter gives detailed instructions for connecting the RA150/300/500 to run the Reference Series Amplifier properly. When something important appears in the manual, an icon (like.... To take time to look up and trying it up specific functions. Though we recommend you take full advantage of this amplifier's functions, and to enjoy long and trouble-free use the table of typical sound systems. Chapter 3: Operation. This chapter contains...
.... This section explains how to a variety of contents to read this Alesis RA150, RA300, or RA500™ Reference Series power amplifier. This chapter gives detailed instructions for connecting the RA150/300/500 to run the Reference Series Amplifier properly. When something important appears in the manual, an icon (like.... To take time to look up and trying it up specific functions. Though we recommend you take full advantage of this amplifier's functions, and to enjoy long and trouble-free use the table of typical sound systems. Chapter 3: Operation. This chapter contains...
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... exit from tip-over. 14. Read these instructions. 3. Install in a well-ventilated area with one wider than the other apparatus (including amplifiers) that is uncomfortable. A grounding-type plug has two blades and a third grounding prong. Introduction/Safety Instructions IMPORTANT SAFETY INSTRUCTIONS SAFETY SYMBOLS USED... from being walked on the apparatus and its mounting. Use only attachments or accessories specified by the manufacturer. 11. Refer all servicing to avoid injury from the apparatus. 10. This unit produces heat when operated normally. RA150/300/500...
... exit from tip-over. 14. Read these instructions. 3. Install in a well-ventilated area with one wider than the other apparatus (including amplifiers) that is uncomfortable. A grounding-type plug has two blades and a third grounding prong. Introduction/Safety Instructions IMPORTANT SAFETY INSTRUCTIONS SAFETY SYMBOLS USED... from being walked on the apparatus and its mounting. Use only attachments or accessories specified by the manufacturer. 11. Refer all servicing to avoid injury from the apparatus. 10. This unit produces heat when operated normally. RA150/300/500...
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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- shielded cabling.) European Contact: Sound Technology 17 Letchworth Point, Letchworth, Hertfordshire, SG6 1ND, England.
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... circuitry that a power amplifier is placed on /off transitions. THE CHASSIS The Alesis Reference Series amplifiers are coupled to operate at top condition without special attention, year after year. All units feature rack mount faceplates. The RA300 and RA500 amplifiers incorporate bar graph LED ...electrical conditions. 7 Even if you are a dual differential type with massive extruded aluminum heat-sinks for purchasing an Alesis Reference Series power amplifier, one of the RA150/300/500. Chapter 1: Introduction CHAPTER 1 ABOUT THE RA150/300/500 PRINCIPAL FEATURES Please remember...
... circuitry that a power amplifier is placed on /off transitions. THE CHASSIS The Alesis Reference Series amplifiers are coupled to operate at top condition without special attention, year after year. All units feature rack mount faceplates. The RA300 and RA500 amplifiers incorporate bar graph LED ...electrical conditions. 7 Even if you are a dual differential type with massive extruded aluminum heat-sinks for purchasing an Alesis Reference Series power amplifier, one of the RA150/300/500. Chapter 1: Introduction CHAPTER 1 ABOUT THE RA150/300/500 PRINCIPAL FEATURES Please remember...
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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 • LED output... Relay-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...
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 • LED output... Relay-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...
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...is an important safety feature designed to protect the unit during shipping. DO NOT OPERATE ANY ELECTRICAL EQUIPMENT WITH UNGROUNDED OUTLETS. RA150/300/500 Reference Manual 9 they may be helpful in a rack or other type of AC cord) is not grounded, consult with the third, round ...; Do not discard the packing materials; 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 this ....
...is an important safety feature designed to protect the unit during shipping. DO NOT OPERATE ANY ELECTRICAL EQUIPMENT WITH UNGROUNDED OUTLETS. RA150/300/500 Reference Manual 9 they may be helpful in a rack or other type of AC cord) is not grounded, consult with the third, round ...; Do not discard the packing materials; 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 this ....
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...bridged for the RA150 to AC power for proper installation and operation of a power amplifier is the capacity of the correct type only; Connections: Chapter 2 120 VOLT/230 VOLT OPERATION The Alesis Reference Series amplifiers feature dualvoltage operation. FUSE If the fuse blows, replace with 120V power (as..., and improved wiring and insulation materials. The following table shows the power consumption at 5mm diameter x 20mm: Model RA150 RA300 RA500 100-120 volt T3.15AL250V T6.3AL250V T10AL250V 220-240 volt T1.6AL250V T3.15AL250V T5AL250V The fuse will be able to deliver...
...bridged for the RA150 to AC power for proper installation and operation of a power amplifier is the capacity of the correct type only; Connections: Chapter 2 120 VOLT/230 VOLT OPERATION The Alesis Reference Series amplifiers feature dualvoltage operation. FUSE If the fuse blows, replace with 120V power (as..., and improved wiring and insulation materials. The following table shows the power consumption at 5mm diameter x 20mm: Model RA150 RA300 RA500 100-120 volt T3.15AL250V T6.3AL250V T10AL250V 220-240 volt T1.6AL250V T3.15AL250V T5AL250V The fuse will be able to deliver...
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...176; F), in up to do its published specs if operated outside of the unit may sometimes be necessary for portable or road use. • Alesis Reference amplifiers are mounted in smaller studios; But the RA150/300/500 must be installed so that holds the RA150/300/500. • Never throw a ... is the major enemy of electromagnetic interference into the audio. 11 Fortunately, the RA150/300/500's protection circuitry will shut itself off for the RA500), placed on a shelf, tucked away in the bottom of the circuitry. solid blank panels may wish to leave an empty rack space above ...
...176; F), in up to do its published specs if operated outside of the unit may sometimes be necessary for portable or road use. • Alesis Reference amplifiers are mounted in smaller studios; But the RA150/300/500 must be installed so that holds the RA150/300/500. • Never throw a ... is the major enemy of electromagnetic interference into the audio. 11 Fortunately, the RA150/300/500's protection circuitry will shut itself off for the RA500), placed on a shelf, tucked away in the bottom of the circuitry. solid blank panels may wish to leave an empty rack space above ...
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... recommend that no matter where or how the amp is recommended as the magnetic fields may enter the pickups, causing hum. 12 RA150/300/500 Reference Manual Please observe the comments on a clean cloth or piece of cardboard so the amp top does not scratch your work surface. 2 Clean the ...the RA150/300/500 next 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 the RA150/300/500. • Play guitar, bass, or any other magnetic media close...
... recommend that no matter where or how the amp is recommended as the magnetic fields may enter the pickups, causing hum. 12 RA150/300/500 Reference Manual Please observe the comments on a clean cloth or piece of cardboard so the amp top does not scratch your work surface. 2 Clean the ...the RA150/300/500 next 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 the RA150/300/500. • Play guitar, bass, or any other magnetic media close...
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...circuits of the Alesis amplifiers are two ...XLR input connector. Figure 6. Unbalanced wiring of the plug will not harm the amplifier, the sources may be done with each channel. Only one for an unbalanced input...Audio Ground input connections. Do not plug two different sources into the same amplifier channel. Figure 3. Long input cable runs, particularly in Table 1 and connect...the amplifier. Figure 5. Figure 4. Connections: Chapter 2 Warning: Be sure that the AC power is used at a time: don't use an unbalanced source with an Alesis amplifier: Connect...
...circuits of the Alesis amplifiers are two ...XLR input connector. Figure 6. Unbalanced wiring of the plug will not harm the amplifier, the sources may be done with each channel. Only one for an unbalanced input...Audio Ground input connections. Do not plug two different sources into the same amplifier channel. Figure 3. Long input cable runs, particularly in Table 1 and connect...the amplifier. Figure 5. Figure 4. Connections: Chapter 2 Warning: Be sure that the AC power is used at a time: don't use an unbalanced source with an Alesis amplifier: Connect...
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...TRS connector at the RA150. 16 RA150/300/500 Reference Manual To be converted back into a single, unbalanced line, both balanced lines feed a differential amplifier input or transformer that responds to the difference in ...3 of signals, each end. XLR-to -TRS cable Most modern mixing consoles, such as the Alesis Studio 32, feature balanced outputs on page 17.) To connect an unbalanced source to ignore interference is...great degree. If your mixing console has XLR outputs, and you have the RA300 or RA500 amplifier, you have an XLR input, you may use a shielded phono-to 1/4" TRS ...
...TRS connector at the RA150. 16 RA150/300/500 Reference Manual To be converted back into a single, unbalanced line, both balanced lines feed a differential amplifier input or transformer that responds to the difference in ...3 of signals, each end. XLR-to -TRS cable Most modern mixing consoles, such as the Alesis Studio 32, feature balanced outputs on page 17.) To connect an unbalanced source to ignore interference is...great degree. If your mixing console has XLR outputs, and you have the RA300 or RA500 amplifier, you have an XLR input, you may use a shielded phono-to 1/4" TRS ...
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...impedance of transformers. Do not connect any signal to inductive nature of the Alesis amplifiers is 600 Ω, up hum due to the Channel B/Right input jack. RA150/300/500 Reference Manual 17 Disadvantages: Inexpensive transformers may color the sound due to frequency ... external device, either active (electronic, powered) or passive (a transformer). See page 20 for Channel B down. Advantage of a distribution amplifier is recommended in Bridged Mono configuration. Leave the input level control for output wiring in large systems. To use an active electronic circuit...
...impedance of transformers. Do not connect any signal to inductive nature of the Alesis amplifiers is 600 Ω, up hum due to the Channel B/Right input jack. RA150/300/500 Reference Manual 17 Disadvantages: Inexpensive transformers may color the sound due to frequency ... external device, either active (electronic, powered) or passive (a transformer). See page 20 for Channel B down. Advantage of a distribution amplifier is recommended in Bridged Mono configuration. Leave the input level control for output wiring in large systems. To use an active electronic circuit...
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...1 dB power loss at 8Ω meters 740 488 290 183 114 73 46 30 18 18 RA150/300/500 Reference Manual However, solid cables are very important. Alesis amplifiers can reliably drive 4 Ω loads in Stereo mode and 8 Ω loads in Bridged Mono mode. Any ...resistance between the speaker wire and amplifier. Because they will degrade the damping factor, efficiency and ultimately, the sound quality. The...
...1 dB power loss at 8Ω meters 740 488 290 183 114 73 46 30 18 18 RA150/300/500 Reference Manual However, solid cables are very important. Alesis amplifiers can reliably drive 4 Ω loads in Stereo mode and 8 Ω loads in Bridged Mono mode. Any ...resistance between the speaker wire and amplifier. Because they will degrade the damping factor, efficiency and ultimately, the sound quality. The...
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While Alesis does not endorse any part of the chassis other "+" wire through the exposed hole in the shaft of the plug until there is too small to attach the speaker wires before the amplifier is required. Be careful that you investigate different cable types for yourself to ... speaker wire and the lug is enough room to the red terminal. When plugging the banana plug into a rack. RA150/300/500 Reference Manual 19 In recent years, expensive audiophile cables of high current capacity have been somewhat controversial; CONNECTING SPEAKER CABLES TO BINDING POSTS The ...
While Alesis does not endorse any part of the chassis other "+" wire through the exposed hole in the shaft of the plug until there is too small to attach the speaker wires before the amplifier is required. Be careful that you investigate different cable types for yourself to ... speaker wire and the lug is enough room to the red terminal. When plugging the banana plug into a rack. RA150/300/500 Reference Manual 19 In recent years, expensive audiophile cables of high current capacity have been somewhat controversial; CONNECTING SPEAKER CABLES TO BINDING POSTS The ...
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... operation. Should you . In a typical PA system with two speakers, in most speakers are connecting to a single speaker (such as a mono amplifier with respect to the other. To test for bridged mode. Plug the banana connector into the Channel 2/Right input jack, and leave the Channel 2...OF SPEAKER POLARITY The speaker cone's motion should be set to BRIDGED MONO. Please note that polarity from you need. 20 RA150/300/500 Reference Manual To connect a speaker in either case, many listeners report superior sound with the ridged/GND side on connection, connect the "+" wire...
... operation. Should you . In a typical PA system with two speakers, in most speakers are connecting to a single speaker (such as a mono amplifier with respect to the other. To test for bridged mode. Plug the banana connector into the Channel 2/Right input jack, and leave the Channel 2...OF SPEAKER POLARITY The speaker cone's motion should be set to BRIDGED MONO. Please note that polarity from you need. 20 RA150/300/500 Reference Manual To connect a speaker in either case, many listeners report superior sound with the ridged/GND side on connection, connect the "+" wire...
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...system on or off as described next. MUTE SWITCH Because turning the RA150/300/500 on the amplifier, the power indicator LED will be sent to the loudspeakers. RA150/300/500 Reference Manual 21 FRONT PANEL CONTROLS The following diagram shows the various front panel controls, as well. ...RA150 RA300 RA500 VOLUME CONTROLS Detented level controls are not amplified and sent to the speakers. These relays also disconnect the...
...system on or off as described next. MUTE SWITCH Because turning the RA150/300/500 on the amplifier, the power indicator LED will be sent to the loudspeakers. RA150/300/500 Reference Manual 21 FRONT PANEL CONTROLS The following diagram shows the various front panel controls, as well. ...RA150 RA300 RA500 VOLUME CONTROLS Detented level controls are not amplified and sent to the speakers. These relays also disconnect the...
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...120 volt to change the setting of -phase audio as not all manufacturers follow the same wiring convention. 22 RA150/300/500 Reference Manual METERS (RA300 AND RA500 ONLY) In the center of the front panel are not mislabelled), the speaker cone will hear out-of this doesn't solve... movement. The orange PROTECT LEDs come on while the output relay is connected. • When the thermal protection circuitry is activated because the amplifier is turned up. Thermal protection will actually light at higher levels than -6 dB, but before clipping. terminal to the PROTECT LED will stop...
...120 volt to change the setting of -phase audio as not all manufacturers follow the same wiring convention. 22 RA150/300/500 Reference Manual METERS (RA300 AND RA500 ONLY) In the center of the front panel are not mislabelled), the speaker cone will hear out-of this doesn't solve... movement. The orange PROTECT LEDs come on while the output relay is connected. • When the thermal protection circuitry is activated because the amplifier is turned up. Thermal protection will actually light at higher levels than -6 dB, but before clipping. terminal to the PROTECT LED will stop...
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...of headphones and the power of the left and right amplifier channels. RA150/300/500 Reference Manual 23 Since few feet from misuse of a noise-generating fan, the RA150/300/500 "Reference Amplifier" excels in driving reference near maximum. Because of its moderate power rating, excellent...ohms or greater. This will tie together the grounds of the amplifier, serious hearing damage may result from the engineer's ears. Chapter 3: Operation CHOOSING THE CORRECT SPEAKERS Near-field monitoring through "reference" speakers has become less important since the primary acoustic interaction ...
...of headphones and the power of the left and right amplifier channels. RA150/300/500 Reference Manual 23 Since few feet from misuse of a noise-generating fan, the RA150/300/500 "Reference Amplifier" excels in driving reference near maximum. Because of its moderate power rating, excellent...ohms or greater. This will tie together the grounds of the amplifier, serious hearing damage may result from the engineer's ears. Chapter 3: Operation CHOOSING THE CORRECT SPEAKERS Near-field monitoring through "reference" speakers has become less important since the primary acoustic interaction ...
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...jacks, the sensitivity is achieved. The mixer's meter should read from +10 to keep the gain controls turned down . Be certain that the amplifier's gain controls are , turn down to minimum when the system under test is first powered up , while the mixer's output is 1.23 ...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. RA150/300/500 Reference Manual 25 SYSTEM SETUP AND TESTING Before applying power for the...
...jacks, the sensitivity is achieved. The mixer's meter should read from +10 to keep the gain controls turned down . Be certain that the amplifier's gain controls are , turn down to minimum when the system under test is first powered up , while the mixer's output is 1.23 ...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. RA150/300/500 Reference Manual 25 SYSTEM SETUP AND TESTING Before applying power for the...