Introduction - AKG CA810 Manual

1. Introduction

The CA810 8 Channel Power Amplifier is a unigue single rack-space solution for zoned, distributed
loudspeaker systems with eight separate power amplifiers, each with an output power capability
of 10W (4 Ohms) or 6W (8 Ohms.) The CA810 is passively cooled, and features full short-circuit and
thermal overload protection. The amplifier outputs are muted at turn-on and turn-off, to eliminate
transients.
The CA810 uses a straightforward, low parts count design for long term reliability. The heart of the
power supply is a low radiation toroidal transformer. The toroidal transformer generates less heat
than a comparable non-toroidal type, and emits considerably less 60Hz energy. This is particularly
important when the CA810 is used in close proximity to microphone preamplifiers.
The input to the CA810 is fully balanced and RF filtered. The level control feeds a monolithic power
amplifier. The amplifier has a voltage gain of 26dB (x20). Each power amplifier is internally power
limited to protect itself from short circuits, excessively low impedances, or highly reactive loads.
Thermal limiting is also integrated into the power amplifier, with an intelligent shutdown mode that
minimizes thermal shock to the device under extreme operation. Any two channels may be used
in the bridged mode for higher power (20W/8 Ohms or 12W/16 Ohms).
The block diagram of the CA810 is shown below.
Channel 1 of 8
Channel
Balanced In
+10V
-10V
Power
Supply
+12V
-12V
Figure 1 - CA810 Block Diagram
Level
Power
Amp
PA8 Power Amplifier
Block Diagram
11
CA810
Speaker
Out