Operation Manual
13. Operation and performance
16
E SERIES Operation Manual rev 2.1.0
13.4.3. Output bridge mode and asymmetric loading
The E Series is designed with inherently bridged outputs for a high voltage swing, with full headroom accessed in
the 70 V mode. So, in some ways the amplier is a 4 channel amplier with permanently bridged outputs which
turns it into a 2 channel amplier. This design also accommodates asymmetric loading, wherein only one channel
can be connected and draw all power from the power supply. Alternatively, one channel can be connected and
congured as a “high power” channel while another is connected and congured as a “low power” channel. For
example, a 4 ohm loudspeaker could draw all the power available from the power supply in one channel when it is
the only loudspeaker connected to the amplier. If another channel is connected, any power used by this second
“low power” channel will limit the “high power” channel from using all available power.
The power available in each channel is determined by the setting of the RSL switch and the impedance of the
connected load. Power available per channel in some typical applications is shown in the following sample tables.
Note that because the two channels are identical, the channels given below are reversible. (If settings of channel 2
are same as for channel 1 shown below, then options for channel 1 are same as for channel 2 below.)
From one perspective, the functionality of asymmetric loading is very intuitive: essentially, power not used in one
channel is available through the other channel, but within limits determined by the load impedances for each
channel and the setting of the RSL switch. However, the possible combinations are many, and performance
limitations may apply in some scenarios.
The tables below illustrate power levels available in different scenarios with different ampliers. These are not
complete, but given only to illustrate the concept; more complete data for all three ampliers is given in
Section 14.3.
System example A: 70 V systems on both channels
Channel 1 Channel 2
Model RSL switch Load type
Power
available
RSL switch Load type
Power
available
E 4:2 70 V 70 V 50 W 70 V 70 V 350 W
E 4:2 70 V 70 V 200 W 70 V 70 V 200 W
E 8:2 70 V 70 V 100 W 70 V 70 V 700 W
E 8:2 70 V 70 V 0 W 70 V 70 V 800 W
E 12:2 70 V 70 V 200 W 70 V 70 V 1000 W