Installation Guide

VA Series Installation Guide V1.18
Internal Settings
WARNING – DANGER
Changing the internal settings requires to open the unit. Prior to opening the unit, the unit shall be disconnected
from any AC supply. Any work on an open unit shall be expedited only by qualied, certied personnel.
Output conguration (hi-voltage/low-impedance)
Each channel of a VA Series amplier may be congured EITHER for driving low impedance loudspeakers (4 ohms minimum),.
or for driving 25/70/100 V-line loudspeaker systems.
Ampliers are shipped with all channels congured for driving 25/70/100 V-line systems. To convert a channel to low-impedance
operation:
• Disconnect the amplier from the AC mains supply.
• Remove the top lid.
• Identify the output transformer(s) for the channel(s) to be converted from the diagrams below:
VA 4120
Ch 1 Ch 2 Ch 3 Ch 4
Power
transformer
VA 2120
Ch 1
Ch 2
Power
transformer
Each transformer’s windings terminate in a pair of in-line, multipin connectors. The primary winding (red and black wires)
terminates in a 2-pin female connector, and the secondary winding (blue, white, yellow and purple wires) terminate in a 4-pin
female connector. Unplug the 2-pin connector: the mating male part of it (also red and black wires) is the power amplier
output. See diagram below:
Pri. Sec.
From amplifier
output (Lo-Z)
100 V
70 V
COM
Red
Black
White
Purple
Blue
Yellow
25 V
F
F
M
FM
Red
Black
Red
Black
To Lo-Z output
connector
To 100/70/25 V-line
output connector
Connection for
Lo-Z operation
Connection for
100/70/25 V-line
operation
• Identify the red and black pair of wires from the low-Z output terminals: these also terminate in a 2-pin female connector,
currently unplugged. Plug this into the male amplier output connector from the previous step.
• Repeat the above procedure for any other channel(s) requiring conversion to low-impedance operation.
• Replace the top lid.
If at any time it is necessary to convert a low-impedance output back to 25//70/100 V-line operation, reverse the above
procedure, reconnecting the amplier output to the transformer primary.