Altec Lansing 4200A Stereo Amplifier User Manual


 
9
Operating Manual 6125A and 4200A Multi-Channel Power Amplifier
7.9 AC Inlet
The 6125A and 4200A amplifiers can be config-
ured by the customer for operation at either 115VAC or
230VAC mains. Switching from one to the other simply
requires the following steps:
1.) Unplug the amplifier from the wall and re-
move the power cord from the rear of the amplifier.
2.) Using a small screwdriver as a lever, unlatch
the fuse holder in the AC inlet and remove it.
3.) Remove the voltage selection insert and ro-
tate until the new nominal mains voltage level indication
(115 or 230) is on top and properly oriented for reading.
4.) Replace the voltage selection insert in the AC
inlet, making sure that it is plugged in all the way.
5.) Replace the fuse with the appropriate size (see
#6 below), and press the fuseholder back into the AC inlet
until it latches.
6.) Using a power cord of the appropriate size
and with the appropriate terminations, plug the cord into
the rear of the amplifier and then into the wall. The ampli-
fier is now ready for use at the new mains voltage.
If the mains voltage is 110-125VAC, the required
fuse is MDA 12, 250V, and the required power cord is 3-
wire grounded, 13 Amp (16AWG) minimum.
If the mains voltage is 220-250VAC, the required
fuse is MDA 10, 250V, and the required power cord is 3-
wire grounded, 10 Amp (18AWG) minimum.
8. SELF-PROTECTION FEATURES
The 6125A and 4200A amplifiers contain circuitry
to self-protect during extreme fault conditions. These fault
conditions are:
1.) Power supply undervoltage
2.) Power supply overvoltage
3.) Output overcurrent
4.) Heat sink overtemperature
5.) Unacceptable DC or high frequency output content
6.) AC power interruption
Except for AC power interruption, the detection
of any fault will result in the activation of protection cir-
cuitry on a particular module, which consists of two chan-
nels. That is, a short circuit on the output of channel 1
will result in both channel 1 and channel 2 entering pro-
tect mode. This is because the signal processing module,
which processes both channels simultaneously, does not
distinguish between the two channels within a channel pair
when processing a fault.
An AC power interruption will result in all chan-
nels entering protect mode simultaneously, just as if the
amplifier is being turned off.
Outputs
Model 6125A
shown.
Model 4200A
has only four
channels.