Related Manuals for Alesis POWER AMPLIFIER RA150
Summary of Contents for Alesis POWER AMPLIFIER RA150
- Page 1 REFERENCE SERIES ™ ™ ™ POWER AMPLIFIERS EFERENCE ANUAL ©2000 Alesis Corporation...
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Page 2: Alesis Contact Information
Alesis RA150-500 Reference Manual © Copyright 2000, Alesis Studio Electronics, Inc. All rights reserved. Reproduction in whole or in part is prohibited. “RA150/300/500” and “Reference Series” are trademarks of Alesis Studio Electronics, Inc. ALESIS CONTACT INFORMATION Alesis Studio Electronics, Inc. -
Page 3: Table Of Contents
System Setup and Testing ...25 Setting the Gain Properly...25 Output Relays/Thermal Cycling ...26 ROUBLESHOOTING 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 PECIFICATIONS ...34 NDEX... -
Page 4: Introduction
Introduction/Safety Instructions NTRODUCTION Thank you for purchasing this Alesis RA150, RA300, or RA500™ Reference Series power amplifier. To take full advantage of this amplifier’s functions, and to enjoy long and trouble-free use, please read this user’s manual carefully. OW TO... -
Page 5: Important Safety Instructions
MPORTANT AFETY SYMBOLS USED IN THIS PRODUCT This symbol alerts the user that there are important operating and maintenance instructions in the literature accompanying this unit. This symbol warns the user of uninsulated voltage within the unit that can cause dangerous electric shocks. -
Page 6: Instructions De Sécurité Importantes (French)
Introduction/Safety Instructions NSTRUCTIONS DE YMBOLES UTILISÉS DANS CE PRODUIT Ce symbole alèrte l’utilisateur qu’il existe des instructions de fonctionnement et de maintenance dans la documentation jointe avec ce produit. Ce symbole avertit l’utilisateur de la présence d’une tension non isolée à l’intérieur de l’appareil pouvant engendrer des chocs électriques. -
Page 7: Beim Benutzen Dieses Produktes Beachten Sie
ENUTZEN DIESES FOLGENDEN ICHERHEITSHINWEISE Lesen Sie die Hinweise. 2. Halten Sie sich an die Anleitung. 3. Beachten Sie alle Warnungen. 4. Beachten Sie alle Hinweise. 5. Bringen Sie das Gerät nie mit Wasser in Berührung. 6. Verwenden Sie zur Reinigung nur ein weiches Tuch. -
Page 8: Ce Declaration Of Conformity
Product Name: Model Type: conforms to the following Standards: Safety: EMC: European Contact: October 2000 ONFORMITY Alesis Corporation 1633 26th Street Santa Monica, CA 90404 RA150/300/500 Audio amplifier EN60065 EN55103:1997 Class B (all tests were performed with fully- shielded cabling.) -
Page 9: About The Ra150/300/500
Even if you are an audio veteran, we urge you to read the entire manual to make the best use of the RA150/300/500. Thank you for purchasing an Alesis Reference Series power amplifier, one of the most advanced and highest value amplifiers available. -
Page 10: About This 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 LED output level metering (RA 300, RA 500) Front panel level controls Overload/Fault indicators Bridged mono operation Balanced 1/4”... -
Page 11: Connections
You as the consignee must make any shipping claims; neither your dealer nor Alesis can do this for you. If the amplifier was not shipped to you, i.e. you picked it up from your dealer, contact the dealer as soon as possible for assistance. -
Page 12: 120 Volt/230 Volt Operation
Connections: Chapter 2 120 V /230 V The Alesis Reference Series amplifiers feature dual- voltage operation. The AC input voltage is selected by a recessed switch on the back panel. The tab is recessed and a tool (small screw driver, pencil, pen, etc.) is required to shift from 120-volt to 230-volt... -
Page 13: Operating Environment
0° C to +50° C (32° F to 122° F), in up to 80% non-condensing humidity. These are not absolute limits, but Alesis cannot guarantee that the RA150/300/500 will meet its published specs if operated outside of these ranges. If necessary, use a fan to blow air over the RA150/300/500 and promote cooler operation. -
Page 14: Mounting On A Shelf Or In A Non-Rack Enclosure
Connections: Chapter 2 OUNTING ON A NCLOSURE 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 the amplifier bottom. To properly mount the stick-on feet:... -
Page 15: Inputs
NPUTS NPUT HARACTERISTICS The RA150/300/500 include two balanced, 1/4" TRS (tip-ring-sleeve, 3-conductor) phone jack inputs, and unbalanced RCA/phono inputs. The RA300 and RA500 feature combination XLR input jacks as well. The inputs are wired according to IEC standards, as shown in the table below. Connection Audio Ground High (+) - Page 16 Warning: Be sure that the AC power is off prior to connecting or disconnecting any signal wiring. The input circuits of the Alesis amplifiers are electronically balanced. They may be fed from either symmetrical (“balanced”) or unbalanced sources. On the RA300 and RA 500, there are two combination XLR/1/4”...
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Page 17: Cables
RA150/300/500 Reference Manual ABLE If you decide to wire your own cables, Alesis recommends that you use three-conductor shielded cable (even in an installation that uses unbalanced wiring) with either a braided or foil-type shield. -
Page 18: Balanced Or Unbalanced
RA150/300/500: You have two options: TRS-to-TRS cable Most modern mixing consoles, such as the Alesis Studio 32, feature balanced outputs on 1/4" TRS jacks. This is the same balancing connector used by the RA150/300/500. Get a 3-conductor cable with a 1/4"... - Page 19 RA150/300/500 Reference Manual To feed the same source to several different amplifiers: The input impedance of the Alesis amplifiers is 20 configuration. Thus, the inputs of several amplifiers may be connected in parallel if desired. The maximum number of amplifier channels will depend on the minimum output load impedance of the device feeding the amplifiers.
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Page 20: Outputs
Warning: Be sure that the AC power is off prior to connecting or disconnecting any signal wiring. S THE Alesis amplifiers can reliably drive 4 Stereo mode and 8 loads in Bridged Mono mode. However, the impedance of a loudspeaker varies with frequency, and its nominal rated impedance is not necessarily its minimum impedance. -
Page 21: Connecting Speaker Cables To Binding Posts
While Alesis does not endorse any particular brand of cable, we suggest that you investigate different cable types for yourself to discover if they improve the sound of your particular setup. -
Page 22: The Importance Of Speaker Polarity
Connections: Chapter 2 MPORTANCE OF OLARITY The speaker cone’s motion should mimic the instrument it’s reproducing. For example, a kick drum pushes air toward you on the initial transient, so a speaker reproducing a kick drum should have its cone push air toward you. If the polarity is reversed, the cone will suck air away from you. -
Page 23: Operation
RONT ANEL ONTROLS The following diagram shows the various front panel controls, as described next. RA150 RA300 RA500 OLUME ONTROLS Detented level controls are on the front panel, where they can be easily adjusted if necessary. These regulate the input signal going into the RA150/300/500. -
Page 24: Protect/Clip Indicators
Operation: Chapter 3 ROTECT NDICATORS Clip lights for each channel indicate the onset of actual clipping. Even if the problem occurs for only a few microseconds, a pulse-stretching circuit will allow the LED to light long enough for you to see that a problem is occurring. -
Page 25: Using The Ra150 As A Headphone Amplifier
RA150 SING THE EADPHONE MPLIFIER The RA150 is particularly suited for use driving high-impedance headphones in studio applica- tions. However, the power is considerably greater than that provided by most "headphone amplifiers", which are often rated at 1 watt or below. -
Page 26: About Ground Loops
Operation: Chapter 3 BOUT ROUND A hum or buzz may be introduced into some audio systems by a phenomenon known as a ground loop. This can occur if a piece of equipment “sees” two or more different paths to ground, as shown below. shielded cable Device A... -
Page 27: System Setup And Testing
YSTEM ETUP AND Before applying power for the first time, double check the wiring to insure that everything is firmly connected and that the proper signals are being fed to the proper places. If a low frequency signal in a multi-amplified system is applied to a high frequency transducer, the transducer can be damaged, and a loose connection can cause noise... -
Page 28: Output Relays/Thermal Cycling
Operation: Chapter 3 Amplifier input clipping On the other hand, the maximum level at the amplifier’s input terminals is +26 dBu, regardless of the setting of the channel input level controls. It is possible that the output signal from the source may be too high and, thus, distorted before it reaches the amplifier gain control, either because the source device is clipping or the amplifier input... -
Page 29: Troubleshooting
Once all gain adjustments are made and proper operation is confirmed, no special considerations are required for Alesis Reference Series amplifiers. Aside from the front panel gain controls, there are no user adjustments or routine maintenance operations necessary (or available). If you experience problems while operating your RA150/300/500, please use the following table to locate possible causes and solutions before contacting Alesis Product Support for assistance. -
Page 30: Care And Maintenance
Troubleshooting: Chapter 4 Symptom Audio cuts in and out Unit shuts down, all lamps are off Thin or Muffled Sound ARE AND AINTENANCE LEANING Disconnect the AC cord, then use a damp cloth to clean the RA150/300/500’s metal and plastic surfaces. -
Page 31: Obtaining Repair Service
Tape a note to the top of the unit describing the problem, include your name and a phone number where Alesis can contact you if necessary, as well as instructions on where you want the product returned. Alesis will pay for standard one-way shipping back to you on any repair covered under the terms of this warranty. -
Page 32: Specifications
Specifications Reference 150 Size Rack units Weight Rated output, per channel 4 ohms @ 1kHz, .02% THD+N 8 ohms @ 1kHz, .05% THD+N 8 ohms, bridged mono mode Signal to Noise Ratio Frequency Response Damping Factor Slew Rate Input Sensitivity Maximum input level Input impedance Crosstalk... - Page 33 Reference 500 Size Rack units Weight Rated output, per channel 4 ohms @ 1kHz, .02% THD+N 8 ohms @ 1kHz, .05% THD+N 8 ohms, bridged mono mode Signal to Noise Ratio Frequency Response Damping Factor Slew Rate Input Sensitivity Maximum input level Input impedance Crosstalk All measurements done over a 20Hz-22,000Hz range with 1KHz sine wave at Full Scale, except for the dynamic...
- Page 34 Specifications RA300 RA500 RA150/300/500 Reference Manual...
- Page 35 150 watts (RA150), 300 watts (RA300), or 500 watts (RA500) into an 8-ohm load when operated in bridged mono mode with no more than .05% total harmonic distortion. The amplifier shall be an Alesis RA150/300/500 Reference Series power amplifier. at least Specifications...
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Page 36: Index
Index 120-volt to 230-volt conversion, 10, 22 AC cord, 9 AC power, 10 balanced inputs, 14 balanced lines, 16 banana plugs, 19 Bridged Mono mode, 17, 20 cables shielded input, 15 speaker, 18 class AB, 7, 33 cooling, 7, 11 direct box, 17 Fuse, 10 gain setting, 25... -
Page 37: Alesis Limited Warranty
ALESIS reserves the right to update any unit returned for repair. ALESIS reserves the right to change or improve design of the product at any time without prior notice. - Page 38 Warranty RA150/300/500 Reference Manual...
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