RA150/300/500 Reference Manual 1
CONTENTS
Introduction......................................................2
How to Use This Manual...........................2
IMPORTANT SAFETY INSTRUCTIONS.... 3
Instructions de Sécurité Importantes (French)......4
Beim Benutzen dieses Produktes 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........................................9
The AC Cord and Grounding.................... 9
120 Volt/230 Volt Operation....................10
Fuse.......................................................10
Electrical Service to the RA150/300/500... 10
Operating Environment................................... 11
Temperature Considerations in Rack
Mounting............................................... 11
Other Rack Mounting Tips...................... 11
Mounting on a Shelf or in a Non-Rack
Enclosure............................................... 12
Avoiding Electromagnetic Interference.... 12
Inputs............................................................. 13
Input Jack Characteristics........................ 13
Cables....................................................15
Cable Wiring Tips...................................15
Balanced or Unbalanced?........................ 16
Outputs ..........................................................18
What's the Load Impedance?................... 18
Connectors..............................................18
Speaker Cables........................................18
Connecting Speaker Cables to Binding
Posts.......................................................19
The Importance of Speaker Polarity..........20
Output Connections for Bridged
Operation...............................................20
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 Service.........................29
Customers outside the USA and
Canada:..................................................29
SPECIFICATIONS...............................30
INDEX.............................................34