11
9) Bridge mode switch: use this switch to convert the amplifier into a mono bridge amplifier. In
this case you can apply an input signal to the channel 1 input only ! Leave the channel 2
connectors open ! Bridge mode input level is controlled by the channel 1 volume controller
only. The ‘BR’ led on the front panel will indicate that the amplifier is in bridge mode. Minimum
bridge mode speaker load is 8 ohms. Never use the speaker output –(minus) connectors in
bridge mode !
10) Speaker load impedance selector channel 1: set this selector correctly according to the
actual load impedance. For 4 to 8 ohms applications: switch is not pushed in. For 2 to 3
ohm applications: push the button in. Please note that the impedance mentioned is the total
load of the amplifier channel, this means that if you connect for example 3 speakers with 8
ohm impedance, you MUST push the button in because the load on the amplifier is 8 : 3 =
2.7 ohms. Use channel 1 impedance selector in case of bridge operation. In case of bridge
operation this switch must be put to 4-8 ohm operation because the minimum load impedance
in bridge mode is 8 ohm. Less than 8 ohms in bridge mode is not allowed !
11) Channel 1 balanced input on Neutrik XLR connector, this connector is wired in parallel to
connector ‘12’. This allows you to link the balanced signal to another amplifier.
12) Channel 1 balanced input on Neutrik XLR connector, this connector is wired in parallel to
connector ‘11’. This allows you to link the balanced signal to another amplifier.
13) Channel 1 unbalanced input on cinch connectors: use the top or bottom cinch connector to
apply an unbalanced signal on channel 1. These connectors are wired in parallel, this means
you can use the second connector as a signal link connector.
What is bridge mode ?
In bridge mode, you can unite the power of 2 small amplifiers into 1 giant amp.
The resulting power usually is more than double the power of both amplifiers used
individually with the same load. There is a simple reason for this power boost:
because the speaker load is wired to the channel’s positive (hot) connectors, the
amplifiers ‘feel’ half of the actual speaker’s impedance. This means that, despite
the fact that you connect for example an 8 ohm speaker, the amp thinks there is a 4
ohm load, resulting in higher power output per amplifier, and since both amplifiers
work in bridge mode, this increased power is doubled. As a result, the minimum load
impedance in bridge mode is limited to 8 ohms, because every amplifier only ‘feels’
half of this impedance. Set the speaker impedance selector of channel 1 to the 4-8
ohms position for 8 ohms(or higher) loads in bridge mode.
