Instruction/ maintenance manual of the product RA500 Alesis
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REFERENCE SERIES POWER AMPLIFIERS R EFERENCE M ANUAL ©2000 Alesis Corporation ™ ™ ™.
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.
RA150/300/500 Reference Manual 1 C ONTENTS Introduction ...................................................... 2 How to Use This Manual ........................... 2 I MPORTANT S AFETY I NSTRUCTIONS .... 3 Instructions de Sécurité Importantes (French) .
Introduction/Safety Instructions 2 RA150/300/500 Reference Manual I 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.
Introduction/Safety Instructions RA150/300/500 Reference Manual 3 I MPORTANT S AFETY I NSTRUCTIONS S 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.
Introduction/Safety Instructions 4 RA150/300/500 Reference Manual I NSTRUCTIONS DE S ÉCURITÉ I MPORTANTES (F RENCH ) S 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.
Introduction/Safety Instructions RA150/300/500 Reference Manual 5 B EIM B ENUTZEN DIESES P RODUKTES BEACHTEN S IE BITTE DIE FOLGENDEN S ICHERHEITSHINWEISE : (G ERMAN ) 1. Lesen Sie die Hinweise. 2. Halten Sie sich an die Anleitung. 3. Beachten Sie alle Warnungen.
Introduction/Safety Instructions 6 RA150/300/500 Reference Manual CE D ECLARATION OF C ONFORMITY Manufacturer’s Name: Alesis Corporation Manufacturer’s Address: 1633 26th Street Santa Monica, CA 9.
Chapter 1: Introduction RA150/300/500 Reference Manual 7 C HAPTER 1 A BOUT THE RA150/300/500 P RINCIPAL F EATURES Please remember that a power amplifier is a high-current, high-power device and should be treated with respect and care. 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.
Introduction: Chapter 1 8 RA150/300/500 Reference Manual Reference Series Features- • DC coupled, fully complementary discrete amplifier topology • Actively biased, dual differential input stages .
Chapter 2: Connections RA150/300/500 Reference Manual 9 C HAPTER 2 C ONNECTIONS U NPACKING AND I NSPECTION Your Alesis RA150/300/500 was carefully packed at the factory, and the shipping carton was designed to protect the unit during shipping.
Connections: Chapter 2 10 RA150/300/500 Reference Manual 120 V OLT /230 V OLT O PERATION 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.
Chapter 2: Connections RA150/300/500 Reference Manual 11 refrigerators, coffee pots, toasters, air conditioning, or stage lighting, plug the RA150/300/500 into a different circuit with a lesser load.
Connections: Chapter 2 12 RA150/300/500 Reference Manual M OUNTING ON A S HELF OR IN A N ON -R ACK E 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.
Chapter 2: Connections RA150/300/500 Reference Manual 13 I NPUTS I NPUT J ACK C 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.
Connections: Chapter 2 14 RA150/300/500 Reference Manual 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.
Chapter 2: Connections RA150/300/500 Reference Manual 15 C ABLES Use only high quality cables when interfacing equipment with the RA150/300/500. These should be good quality shielded cables with a stranded (not solid) internal conductor. Although quality cables cost more, they do make a difference.
Connections: Chapter 2 16 RA150/300/500 Reference Manual B ALANCED OR U NBALANCED ? With long cable runs (e.g., over 6 meters/20 feet) in noisy electrical environments, the cable itself can act as an “antenna” and pick up RF fields, AC hum, or other types of interference.
Chapter 2: Connections RA150/300/500 Reference Manual 17 Isolation transformer or direct box If your mixer or other sound source doesn't have a balanced output, you may turn it into a balanced signal with an external device, either active (electronic, powered) or passive (a transformer).
Connections: Chapter 2 18 RA150/300/500 Reference Manual O UTPUTS Warning: Be sure that the AC power is off prior to connecting or disconnecting any signal wiring. W HAT ' S THE L OAD I MPEDANCE ? Alesis amplifiers can reliably drive 4 Ω loads in Stereo mode and 8 Ω loads in Bridged Mono mode.
Chapter 2: Connections RA150/300/500 Reference Manual 19 In recent years, expensive audiophile cables of high current capacity have appeared. These have been somewhat controversial; some feel the extr.
Connections: Chapter 2 20 RA150/300/500 Reference Manual T HE I MPORTANCE OF S PEAKER P 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.
Chapter 3: Operation RA150/300/500 Reference Manual 21 C HAPTER 3 O PERATION F RONT P ANEL C ONTROLS The following diagram shows the various front panel controls, as described next. RA150 RA300 RA500 V OLUME C ONTROLS Detented level controls are on the front panel, where they can be easily adjusted if necessary.
Operation: Chapter 3 22 RA150/300/500 Reference Manual P ROTECT /C LIP I 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.
Chapter 3: Operation RA150/300/500 Reference Manual 23 U SING THE RA150 AS A H EADPHONE A 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.
Operation: Chapter 3 24 RA150/300/500 Reference Manual A BOUT G ROUND L OOPS 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.
Chapter 3: Operation RA150/300/500 Reference Manual 25 S YSTEM S ETUP AND T ESTING 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.
Operation: Chapter 3 26 RA150/300/500 Reference Manual 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.
Chapter 4: Troubleshooting RA150/300/500 Reference Manual 27 C HAPTER 4 T ROUBLESHOOTING T ROUBLESHOOTING I NDEX Once all gain adjustments are made and proper operation is confirmed, no special considerations are required for Alesis Reference Series amplifiers.
Troubleshooting: Chapter 4 28 RA150/300/500 Reference Manual Symptom Cause Solution Intermittent amplifier input signal Clean input connectors, check wiring If the sound cuts out for a minute or two a.
Chapter 4: Troubleshooting RA150/300/500 Reference Manual 29 O BTAINING R EPAIR S ERVICE Before contacting Alesis, check over all your connections, and make sure you’ve read the manual. Customers in the USA and Canada: If the problem persists, contact Alesis USA at www.
Specifications 30 RA150/300/500 Reference Manual S PECIFICATIONS Reference 150 Size 18.9" W x 3.9" H x 10.25" D (480mm x 99 mm x 260 mm) Rack units 2RU height Weight 15lbs = 6.8Kg Rated output, per channel 4 ohms @ 1kHz, .02% THD+N 75 watts RMS per channel 8 ohms @ 1kHz, .
Specifications RA150/300/500 Reference Manual 31 Reference 500 Size 18.9" W x 5.63" H x 10.71" D (480mm x 143 mm x 272 mm) Rack units 3 RU height Weight 28.5lbs = 13.0Kg Rated output, per channel 4 ohms @ 1kHz, .02% THD+N 250 watts RMS per channel 8 ohms @ 1kHz, .
Specifications 32 RA150/300/500 Reference Manual RA500 RA300.
Specifications RA150/300/500 Reference Manual 33 Architect's and Engineer's Specifications The power amplifier shall be a two-channel unit capable of being switched to single-channel bridged mode operation.
Index 34 RA150/300/500 Reference Manual I NDEX 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 .
RA150/300/500 Reference Manual 35 A LESIS L IMITED W ARRANTY ALESIS ("ALESIS") warrants this product to be free of defects in material and workmanship for a period of one (1) year for parts and for a period of one (1) year for labor from the date of original retail purchase.
Warranty 36 RA150/300/500 Reference Manual.
An important point after buying a device Alesis RA500 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Alesis RA500 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Alesis RA500 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Alesis RA500 you will learn all the available features of the product, as well as information on its operation. The information that you get Alesis RA500 will certainly help you make a decision on the purchase.
If you already are a holder of Alesis RA500, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Alesis RA500.
However, one of the most important roles played by the user manual is to help in solving problems with Alesis RA500. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Alesis RA500 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
