AD200 Bass Mk III — instructions for use
Front panel

Power
Standby
Master volume
Bass
Mid-range
Treble
Gain
Passive input
Active input
1. Power
Switches mains power to the amplifier on/off. Connect the supplied IEC/Mains cord to the AC Mains inlet (rear). The power LED will illuminate when the mains switch is set to On. Set the VOL control to zero/minimum before switching on power to the amplifier.
2. Standby
Selects between Standby and Play.
3. Master volume
Adjusts the master volume.
4. Treble
Adjusts the high-end response.
5. Middle
Adjusts the mid-range response.
6. Bass
Adjusts the low-end response.
7. Gain
Adjusts the preamp gain of the amplifier. High levels of this control will cause the preamp valves to overdrive slightly.
8. Passive Input
Plug bass guitars of traditional output into this input. Use a quality shielded instrument cable to connect your instrument to the Input jack socket.
9. Active Input
Plug bass guitars of high output into this input. Use a quality shielded instrument cable to connect your instrument to the Input jack socket.
Rear panel

Slave output
Speaker outputs
Output valve failure fuses
HT fuses
Power input
Voltage selector switch
1. Slave output
The slave output socket is a line level output signal from the output stage of the amplifier. The correct speaker load needs to be also connected when using the slave output.
2. Speaker outputs
Refer to “Before Using Your Amplifier” for full speaker cabinet options. If you are unsure, please contact your Orange dealer.
3. Channel
If an output valve fails, it will blow its corresponding output valve failure fuse. This will remove a pair of output valves from the circuit, resulting in half of the output power being produced by the amplifier. Looking at the back of the amplifier, the output valves 1–4 run from left to right. If the 1 + 3 fault light comes on, the defective output valve will be either number 1 or 3. If the 2 + 4 fault light comes on, the defective output valve will be either number 2 or 4.
4. HT Fuses
The high-tension fuse protects transformers and other circuitry from blowing in the event of an output valve shorting.
5. AC mains input and mains fuse
Refer to “Before Using Your Amplifier“. Connect the supplied IEC cable to the AC mains input. Ensure the Power switch is set to OFF before connecting the IEC cable. The mains fuse is located in the pull-out tray underneath the AC mains input. If the mains fuse blows, replace this fuse only with the exact type and rating as printed on the chassis. If the mains fuse continues to blow, contact your Orange dealer.
6. Voltage selector switch
Refer to “Before Using Your Amplifier”
Little Bass Thing — instructions for use
Front panel

Compressor footswitch input
Volume
Compression
Treble
Frequency control
Mid-range
Bass
PAD switch
Input
1. Compression footswitch input
Connect a latching footswitch to engage or defeat the compression control.
2. Master volume
Adjusts the overall output volume level.
3. Compression
Controls the effect level of the on-board compression circuit. Adding compression can help to smooth out sound peaks and transients for a fatter, more rounded tone. The LED will react to your playing and glow brighter red through the power light when more compression is applied.
4. Treble
Adjusts the high-end response.
5. Frequency
Selects the centre frequency of the mid-range control.
6. Middle
Controls the mid-range frequency band.
7. Bass
Adjusts the low-end response.
8. PAD switch
The PAD switch takes 6 dB off the input sensitivity, which is ideal for active basses.
9. Input
Use a quality shielded instrument cable to connect your instrument to the Input jack socket.
Rear panel

Speaker outputs
Footswitch input
HT fuses
Power input
Fan
1. On/Off switch
Powers the Little Bass Thing on and off. Ensure this is set to the off position before connecting to mains.
2. AC mains inlet
Connect the supplied IEC/mains cord to the mains input and connect the plug to your AC mains supply. Refer to “Before Using Your Amplifier”.
3. Mains fuse
The mains fuse is located in the tray directly below the AC mains inlet. If the mains fuse blows, replace this fuse only with the exact type and rating as printed on the chassis. If the mains fuse repeatedly blows, contact your Orange dealer.
4. Voltage selector switch
This is factory-set for the region in which the amplifier is intended to be sold. Do not tamper with this switch. Refer to “Before Using Your Amplifier”
5. Fan intake
Do not obstruct or place objects into the fan. During sustained periods of high-volume playing, the fan will begin to operate to help cool the amplifier.
6. Speaker outputs
Refer to “Before Using Your Amplifier”. Make sure the correct speaker load and power handling is connected. Total minimum impedance = 4 Ω. Speaker outputs are wired in parallel (speakon connector only). Full output power = 500 W at 4 Ω.
7. Effects loop
Use the effects loop to connect external effects processors/pedals between the unit’s preamp and output stages. Connect the Send socket to the input of external effects, and the Return socket to their outputs.
8. Balanced DI output
Sends a balanced, line-level signal (post-EQ and post-volume) to a mixer or PA system.
9. Ground lift
Engage this button if ground hum becomes a problem when hooked up to external equipment.
OB1-300 / OB1-500 — instructions for use
Front panel

On/off switch
Footswitch input
Volume
Treble
Mid-range
Bass
Blend
Gain
PAD switch
Input
1. Power
LED will illuminate when the mains switch is set to On. Set the Volume control to zero/minimum before switching on power to the amplifier.
2. Gain/Blend footswitch
Connect a latching footswitch (e.g. FS-1) to this jack socket to remotely engage/defeat the Gain and Blend controls. Use a standard instrument/tip-sleeve (mono) cable to connect the footswitch.
3. Master volume
Adjusts the master volume.
4. Treble
(Active and post-Blend) Adjusts the high-end frequencies. Increasing the Treble control produces brighter tones. Higher Gain settings will also add high-end frequencies. Reduce the Treble control to compensate if necessary.
5. Middle
(Active and post-Blend) Adjusts the mid-range frequencies.
6. Bass
(Active and post-Blend) Adjusts the low-end frequencies. Increasing the Bass control produces deeper tones.
7. Blend
Controls the amount of upper harmonics blended with the clean signal. The character of the blended signal is defined by how the Gain control is set. Higher Blend settings will add extra volume, so you may adjust the master Volume to compensate if necessary. With the Gain set to minimum, the Blend control will have the least effect on the overall sound.
8. Gain
Controls the level of gain added to the upper harmonics. The Gain control works in tandem with the Blend control for a variety of sounds. Higher Gain settings produce dirtier tones; lower Gain settings combined with a higher Blend setting can be used for a clean boost to cut through the mix.
9. PAD switch
The PAD switch takes 6 dB off the input sensitivity, which is ideal for active basses.
10. Input
Use a quality shielded instrument cable to connect your instrument to the Input jack socket.
Rear panel

Balanced Output
Line output
Fan intake
Speaker output
Power input
Voltage selector switch
1. Balanced output
Sends a balanced line-level signal (post-EQ, post-Blend, pre-Master Volume) to a mixer and/or PA system. Engage/depress the ground Lift button if ground hum becomes a problem when connecting the amplifier to external equipment.
2. Line output
Sends an unbalanced line level signal (post-EQ, post-Blend, pre-Master Volume) to a mixer and/or PA system.
3. Fan intake
Do not obstruct or place objects into the fan. During sustained periods of high volume, playing the fan will begin to operate to help cool the amplifier.
4. Voltage selector switch
Refer to “Before Using Your Amplifier”. Total minimum impedance = 4 Ω
5. AC mains input and mains fuse
Refer to “Before Using Your Amplifier”. Connect the supplied IEC cable to the mains input. The mains fuse is located in the tray directly underneath the AC mains cable input. If the mains fuse blows, replace this fuse only with the exact type and rating as printed on the chassis. If the mains fuse continues to blow, contact your Orange dealer.
6. Voltage selector switch
Refer to “Before Using Your Amplifier”. This is factory-set for the region in which amplifier is intended to be sold.
Terror Bass — instructions for use
Front panel

Power
Volume
Treble
Mid-range
Bass
Gain
Clean switch
PAD switch
Input
1. Power
Switches mains power to the amplifier on/off. Connect the supplied IEC/Mains cord to the AC Mains inlet (rear). The power LED will illuminate when the mains switch is set to On. Set the Volume control to zero/minimum before switching on power to the amplifier.
2. Volume
Adjusts the master volume.
3. Treble
Adjusts the high-end response.
4. Middle
Adjusts the mid-range response.
5. Bass
Adjusts the low-end response.
6. Gain
Adjusts the Gain level, increasing in saturation as the control is turned clockwise. With all EQ controls turned fully clockwise, maximum levels of overdrive will be achieved. Lower Gain settings produce cleaner tones and may require an increase in the Master volume to compensate. No signal will be present with the gain set to zero.
7. Clean switch
The clean switch gives more headroom and smoother, clean sounds.
8. PAD switch
Reduces the input signal by 6 dB, maintaining a clean signal with higher-output instruments.
9. Input
Use a quality shielded instrument cable to connect your instrument to the Input jack socket.
Rear panel

Speaker outputs
Speaker impedance switch
AC mains inlet and mains fuse
1. Speaker outputs
Refer to ‘Before Using Your Amplifier’ for full speaker cabinet options. If you are unsure, please contact your Orange dealer.
2. Speaker impedance switch
Make sure this switch matches your speaker’s impedance.
3. AC mains input and mains fuse
Refer to “Before Using Your Amplifier“. Connect the supplied IEC cable to the AC mains input. Ensure the Power switch is set to OFF before connecting the IEC cable. The mains fuse is located in the pull-out tray underneath the AC mains input. If the mains fuse blows, replace this fuse only with the exact type and rating as printed on the chassis. If the mains fuse continues to blow, contact your Orange dealer.
Side panel

Balanced DI output
Ground lift button
Effects loop
1. DI out
The DI output is set at professional line level for a padded mixing desk to a PA. An external DI box should still be taken from the actual bass guitar itself in most live situations so that a signal can still be present in case of amplifier failure.
2. Ground lift switch
Engage this button if ground hum becomes a problem when hooked up to external equipment.
3. Effects loop
Use the effects loop to connect external effects processors/pedals between the amp’s preamp and output stages. Connect the Send socket to the input of external effects, and the Return socket to their outputs.