TOA a-503a Specification Guide

THE TOA 500 SERIES
MIXER/POWER AMPLIFIERS are
ideal for a wide variety of
installed sound applications.
Engineered with proven TOA
quality and reliability, the 500
Series is simple to install and oper-
ate, saving you time and money. 

The A-503A (30 W), A-506A (60 W),
and A-512A (120 W) Mixer/
Amplifiers each have six input
channels to accommodate a variety
of input sources and a built-in
power amplifier with transformer-
isolated 25 V, 70 V and 4 ohm
speaker outputs. 

Pre-Out/Power-In jacks allow con-
nection of external signal processing
between the mixer and amplifier
sections. Other features include
booster and tape outputs for con-
necting an external mixer, amplifier
or recording device. A convenient
+24 VDC input allows operation in
remote applications.

The TOA 500 Series are UL and
cUL Listed and carry a five year
warranty.

 

Amplifiers for paging, music distribu-
tion and messaging-on-hold.

 

Engineered for High Performance with
wide frequency response, very low 
noise and distortion, and excellent 
output regulation. 

Three Models: 
A-503A (30 W), A-506A (60 W), 
A-512A (120 W)

25 V, 70 V and 4 Ohm Transformer-
Isolated Speaker Outputs with screw 
terminal connector and protective 
cover plate. 

Two Low Impedance Microphone 
Inputs, balanced, transformer-isolated 
with XLR-F connectors and switchable 
phantom power. 

Three Auxiliary Line Inputs, unbal-
anced with RCA connectors

Hi-Z Mic/Phono Input (switchable), 
unbalanced with RCA/screw terminal  
connectors

Optional Module converts Inputs 3 & 4
to low impedance microphone inputs 
with XLR-F connectors.

External Mute Terminals for switch 
closure override of Inputs 3-5 with 
adjustable mute depth. 

Remote Mic Volume Terminals 
(Input 2) for control with an external 
10k ohm linear-taper potentiometer. 

Insert Jacks for connecting external 
signal processor. 

Booster and Tape Outputs for connect-
ing external mixer, amplifier or record-
ing device.

+24 VDC Input for connection to exter-
nal power source. 

Rear Panel AC Convenience Outlet for 
powering external equipment.

Over-current and Thermal Protection 
Circuitry prevents potential damage 
from overload, short-circuit and over-
heating. 

 

Rack-mount Kit

Perforated Rack Panel (2 RU)

Dual Lo-Z Mic Input Module

Unbalanced-to-Balanced Transformer (600:600 ohms)