Extron Electronics MLA-VC10 - Manual (Page 24)

MLA-VC10 • Installation and Setup
Installation and Setup, cont’d
2-12
Wiring TOA 700 Series amplifiers
TOA 700 series amplifers use a 10k ohm potentiometer instead
of a variable DC voltage on the Remote Volume terminals. To
control volume on these amplifers, follow these steps and see
figure 2-13:
1. Configure the DIP switch setting on the
MLA-VC10 for 10 V, with all switches in
the "ON" position (see figure at right).
2. Use the "-" terminal on the TOA amplifier's
Power Remote terminals as an alternative ground point.
Connect the Ground ( ) terminal of the MLA-VC10 to the "-"
terminal of the TOA 700 Series Power Remote terminals.
3. Although this allows the volume to be controlled using
voltage, the remote volume range will be 12 V. To compensate
for the higher voltage range, add a resistor between the "CTL"
terminal of the MLA-VC10 and the "H" terminal of the TOA
amplifier.
The following chart (information courtesy of TOA Electronics)
shows corresponding resistor and attenuation values:
Resistor Values Attenuation Values
Maximum Minimum
100k ohm 0 dB -25 dB
82k ohm 0 dB -32 dB
68k ohm -2 dB -38 dB
56k ohm -3 dB -47 dB
47k ohm -4 dB -55 dB
4. This will drop the maximum and minimum volume
attenuation but will not achieve complete silence when
volume is set to 0. Use Global Configurator to program a
relay from the MediaLink Controller to the TOA amplifier's
"Mute Control" terminals (see pages 3-5 to 3-9).
5. Configure the Mute Assignment DIP switch on the TOA
amplifier to choose which channels are muted at contact
closure. The figure at right shows switches 8, 7, 6, 5, 4, M
(module), 3, 2, and 1 in the down (ON position), which will
mute all channels.
6. Use Global Configurator 2 software
to configure the
MLA-VC10 driver (see page 3-2).
3 4 1 2 7 8 5 6
ON
DIP Switches
set for 10.0 VDC
ON
3 2 1
8 7 6 5 4
NC
M
1 2 3 M
MUTE ASSIGNMENT
MUTE RECEIVE (INPUT CH)
MUTE SEND
(INPUT CH)