TOA a-903mk2 Guida Specifiche

THE TOA 900 SERIES are widely 
recognized as the industry standard
in installed sound system amplifi-
cation. When reliability and per-
formance are critical – such as in
paging and music distribution for
airport, hospital, and industrial
sound systems – you can count on
the TOA 900 Series to perform
consistently, day-in and day-out.

The A-903MK2 (30 W), A-906MK2
(60 W) and A-912MK2 (120 W)
Modular Mixer/Amplifiers are
engineered for high performance
with wide frequency response,
very low noise and distortion, and
excellent output regulation. Eight
module slots allow you to easily
configure custom configurations
using TOA plug-in modules with
an extensive array of features and
connector types. You can increase
the input capacity by connecting a
second mixer or mixer/amplifier to
the rear-panel Bridge In/Out jack.
Outputs include transformer-
isolated 25 V, 70 V and 8 ohm 
(A-903MK2: 4 ohm) plus a direct
low-impedance mode if non-trans-
former operation is required.

Multiple paging priorities are easily
configured using optional mute-
type modules activated by exter-
nal switch-closure or mute-send
modules. Pre-Out/Power-In jacks
allow connection of external signal
processing between the mixer and
amplifier sections. Other features
include protection circuitry, auxil-
iary output, bass/treble controls
and remote master volume terminals.

The 900 Series Mixer/Amplifiers
are UL and cUL Listed and carry a
five year warranty.

 

Amplifiers for paging, background/ 
foreground music distribution and 
music/messaging-on-hold.

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

Three Models: 
A-903MK2 (30 W), A-906MK2 (60 W),
A-912MK2 (120 W)

Eight Module Slots accept any combi-
nation of TOA plug-in modules for 
custom system configurations. 

25 V, 70 V and 8 Ohm Transformer-
Isolated Speaker Outputs with screw 
terminal connector and protective 
cover plate (A-903MK2: 4 ohm).

Direct Low-Impedance Output Mode 
bypasses output transformer.

Dual Mute Bus permits multiple levels
of paging priority using optional 
mute-type modules. 

External Mute Terminals for activating
mute function with external switch-
closure.

Remote Master Volume Terminals for 
control with an external 10k ohm 
linear-taper potentiometer.

Bass/Treble Tone Controls with tone 
defeat switch.

Low Cut Switch to limit low frequency
response.

Auxiliary Output for connecting an 
external mixer or recording device. 

Insert Jacks for connecting external 
signal processing. 

Bridging Input/Output for input 
expansion or recording device.

Normal, Clip, Power, Protect, and 
Signal Indicators provide unit status. 

Rear Panel AC Convenience Outlet for
powering external equipment

Turn-On Delay disconnects output 
during power-up.

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

Plug-in Modules (see individual module specifications)

Rack-mount Kit (2 RU)

Perforated Rack Panel (2 RU)

Volume Control Security Knob

900 Series Module Guide available from http://www.toaelectronics.com