Keep the loudspeaker cables as short as possible and use good quality
stranded cable. Do not use shielded wire, such as microphone or guitar
cable. Remember that the loudspeaker cable robs the power of the
amplifier in two ways; it increases the load impedance and also introduces
resistive power losses.
15
OPERATING MODES
Stereo
For stereo dual channel operation ensure switch S4 (located behind the
plug in card panel on the front of the amplifier) is in the "OUT" position. In
this mode both channels are split and operate independently of each other,
with their level attenuators controlling their respective outputs. Never
connect either output terminal to ground or in parallel.
Tandem (Dual Mono)
For tandem (dual channel-single input) operation connect the link out of
one channel into the input of the other channel using an XLR to XLR cable.
Input Mono Sum
To mono sum input A and B together push "IN" switch S4 (located behind
the plug in module/panel on the front of the amplifier). A level drop of 6dB’s
will occur if only one input is used in this mode of operation. The output
connection is the same as in stereo mode.
Bridged Mono
To bridge the amplifier, depress switch S5 (located behind the removable
panel/module on the front of the amplifier) both channels are then fed by
input 'A'. The output in bridge mode appears on the dedicated 'Bridge out
Speakon'. Only Channel A level attenuator and the LED's associated with
Channel A are operational in bridge mode. If SW4 is depressed this will
sum together input A and B which will then be fed to the bridged output
stage.
Pin -1
Speaker negative
Pin +1
Speaker positive
NB. The recommended minimum nominal impedance for bridged mono is 4
Ohms (equivalent to driving both channels at 2 Ohms) Driving bridged
loads of 4 Ohms or lower with the “max” LED’s permanently "ON" may
trigger protection circuits within the amplifier due to current and thermal
demands. If an over current shut down occurs the power supply will shut
down. To restart the amplifier the power switch must be turned "OFF" then
back "ON". The input level to the amplifier must also be reduced or the
power supply will shut down again.
(See page 18 Protection Features).
Martin Audio – E1300 Amplifier
E
NGLISH
16
All material © 2007. Martin Audio Ltd. Subject to change without notice.
