Acoustic Pre Twin Channel

Welcome to Orange

Thank you for choosing Orange.

Since 1968, when the company was founded, Orange Amplification has been researched and developed by the guitarist for the guitarist. Today, with a team of the industry’s most dedicated engineers, it continues to test the boundaries of conventional amp design to bring you the latest range of heads, cabinets and combos.

Orange’s commitment to quality control, construction and craftsmanship is long established, and each amplifier passes through a rigorous test procedure before shipping, resulting in complete confidence that you will be delighted with your new purchase, and that it will provide you many years of enjoyment and reliability.

The warmth, tonal quality and rich harmonics generated by Orange amplifiers cannot be reproduced by artificial means. Many guitarists have reached the same conclusion: there is nothing as good as an analogue amplifier!

This web page contains valuable technical and safety information. Please take the time to read these instructions and warnings, as the information will enhance the performance and longevity of your amplifier.

Important safety instructions

  1. Read these instructions.
  2. Keep these instructions.
  3. Heed all warnings.
  4. Follow all instructions.
  5. Do not use this apparatus near water or other liquids.
  6. Clean only with a dry cloth.
  7. Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.
  8. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
  9. Do not defeat the safety purpose of the polarised or grounding-type plug. A polarised plug has two blades, with one wider than the other. A grounding-type plug has two blades and a third grounding prong. The wide blade or the third prong are provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for a replacement of the obsolete outlet.
  10. Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the point where they exit the apparatus.
  11. Only use attachments/accessories specified by the manufacturer.
  12. Use only with the cart, stand, tripod, bracket, or table specified by the manufacturer, or sold with the apparatus. When a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.
  13. Unplug this apparatus during lightning storms or when unused for long periods of time.
  14. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.

    This device complies with Part 15 of the FCC rules. Operation is subject to the following two conditions:

    1. This device may not cause harmful interference
    2. his device must accept any interference received, including interference that may cause undesired operation.

    Note: This equipment has been tested and found to comply with the limits for Class B digital devices, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try and correct the interference by one or more of the following measures:

    • Reorient or relocate the receiving antenna.
    • Increase the separation between the equipment and receiver.
    • Connect the equipment to an outlet on a circuit different from that to which the receiver is connected.
    • Consult the dealer or a qualified technician for help.

    Note: Changes or modifications not expressly approved by Orange Music Electronic Company, Ltd. could void the user’s authority to operate the equipment.

    For customers in Canada: Where indicated or stated on the product/unit: This Class B digital apparatus complies with Canadian Interference Regulations CAN ICES-3(B)/NMB-3(B).

    For product operation manual and warranty information, please visit:

    All products are certified/tested to relevant safety standards. For further information please contact us.

Warning for Class I Equipment (where applicable)

This product is a Class I construction and must be connected to a mains socket outlet with a protective earthing connection. Connect the included power cord/plug to an AC mains socket outlet with a protective earthing connection.

The mains fuse is provided for your safety. Disconnect the apparatus before replacing. The fuse rating for your model and region is indicated near the unit’s AC mains inlet. Do not replace it with a fuse of a different type. If the mains fuse repeatedly blows, contact your Orange dealer.

Information on fuses

  • T = Time Delay (“Slow Blow”)
  • mA or A = Rated current, expressed in mA or A
  • L = Low breaking capacity or; H = High breaking capacity

Do not tamper with the voltage-selector switch.

Where applicable, the voltage-selector switch is located on the rear or side of the product. It is set at the factory for the country or region in which the unit is intended to be sold. 

Terminals labelled as “SPEAKER OUTPUTS” must be connected to a speaker cabinet of the designated load () rating using an un-shielded two-conductor cable for speaker use at all times during operation.

To reduce the risk of fire, electric shock AND/OR INJURY:

Do not expose this apparatus to rain or moisture. For indoor use only. Do not use in damp environments, e.g. bathrooms, etc.

Do not place objects containing liquids on or near the product.

Do not operate this apparatus or connect/disconnect a power plug whilst hands are wet.

Do not cover or block ventilation openings. Ensure the apparatus is installed with plenty of space around the unit, as this apparatus may generate heat under normal use.

This equipment is not intended to be used on soft support (like beddings, blankets etc.). This equipment should always be placed on a flat, stable surface.

For units with fan ventilation: Do not obstruct the fan, or place objects into the fan. Keep body parts away from fan blades.

Do not attempt to gain access to the interior of the product. No user-serviceable parts inside. Refer all servicing to a qualified technician.

Do not operate equipment when the protective grille has been removed.

Valves (tubes) (where applicable)

To ensure optimum operation, valves should be replaced once per year. Valve models (except Class A fixed bias) will benefit from having the bias checked when output valves are replaced. Bias checking should be undertaken by a qualified technician.

Before using your amplifier

Voltage-selector switch

The voltage-selector switch and mains fuse is set at the factory for the country or region in which this Orange product is intended to be sold. To prevent serious damage to the product, ensure that the rated AC mains voltage indicated on the product’s rear panel is the same as the mains voltage from your AC mains inlet before connecting the IEC power cable.

If the product is to be used outside of the factory-set region, please ensure the voltage-selector switch (found on the rear or side panel) is set to the correct voltage for the new country/region, and that the appropriate mains fuse is fitted in the pull-out fuse tray below the IEC mains input.

The correct mains fuse rating for the product is printed on the chassis. Use only the same type and rating as specified for the product. Be advised that different operating voltages require the use of different types of line cord and attachment plugs. If you are unsure, please contact your Orange dealer.

Powering on

Always ensure the amp’s volume controls are set to zero before switching on the power to the amplifier.

To prevent hum and electrical noise, operate your amplifier and instruments as far away from other electronic devices (especially fluorescent and neon lamps) as possible, as these generate extremely high levels of electronic noise.

Speaker output connection

Make sure the correct speaker load is connected at all times during operation.

Always connect to a cabinet of an appropriate power rating/handling.

Never use two cabinets of different/mismatched impedance.

Only connect speakers using a quality dedicated speaker cable. Never use an instrument cable. 

Never connect headphones to the speaker outputs.

If you are unsure, please contact your Orange Dealer.

Only connect speaker cabinets in accordance with this manual. Failure to do so will cause damage to the amplifier and void any warranty.


1 × 16 Ohm cabinet — Use the 16 Ohm speaker jack socket (rear of chassis)

2 × 16 Ohm cabinets — Use both of the 8 Ohm speaker jack sockets (rear of chassis)

1 × 8 Ohm cabinet — Use either of the 8 Ohm speaker jack sockets (rear of chassis)


All Orange valve combo amplifiers have an internal speaker load of 16 Ohms and are connected to the amplifier’s 16 Ohm output at the factory. When using an extension cabinet, only ever connect a 16 Ohm cabinet.

To connect an extension cabinet to the combo, reconnect the internal speaker jack to either of the 8 Ohm speaker outputs, and connect a 16 Ohm extension cabinet to the other 8 Ohm speaker output.  

Be sure to reconnect the internal speaker to the 16 Ohm output when an extension cabinet is not attached.


When powering up, ensure the amplifier is set to the STBY position on the front panel for a minimum of two minutes prior to performance. This will prolong the life of the valves. 

The HT fuse(s) on the rear of the chassis will blow in the event of output valve failure in order to protect the internal circuitry from damage. Orange recommends output valves are replaced in full matched sets. Orange models fitted with EL34 or 6550 valves will also benefit from a bias adjustment, which should only be undertaken by a qualified technician. When changing the HT fuse, gently push down on the fuse holder and turn anticlockwise to release the fuse.


The Orange Acoustic Pre Twin Channel is designed to be the hub of your acoustic rig.

Providing full control over a variety of input sources, different FX routing options and independent outputs for every possible setup, the Orange Acoustic Pre Twin Channel brings studio-quality sounds to the live stage and all-in-one simplicity to any recording situation.

Using your Acoustic Pre Twin Channel

Front Panel Features



Activate +48V phantom power when using a  condenser microphone (Check Manufacturer specifcations)

Channel A


Adjusts the high shelf +18dB above 680 hZ


Adjusts the low shelf +/- 12dB below 680 hZ


Adjusts the input level to Channel A.


Adjusts the frequency selected by the Freq control by +/- 18 dB


Selects the centre frequency for the mid control (180Hz – 1.8kHz)


Alters the level of valve gain in the upper frequencies adding harmonics and compression

Channel B


Adjusts the frequency selected by the Freq control by +/- 18 dB


Adjusts the low shelf +/- 12dB below 680 hZ


Adjusts the high shelf +18dB above 680 hZ


Adjusts the input level to Channel B


Selects the centre frequency for the mid control (180Hz – 1.8kHz)



Controls the level of the on-board digital reverb.

Line Volume

Controls the output level of the unbalanced mono line output.

Main Volume

Controls the output level of the balanced XLR outputs.

Rear Panel Features


Input A


Input B


Mute Footswitch


FX Loop Send A


FX Loop Return A


FX Loop Send B


FX Loop Return B


Line output


Main Output A


Main Output B


12V DC

1. Input A

 1/4″ Jack input to Channel A

2. Input B

1/4″ Jack and XLR inputs to Channel B (not to be used simultaneously)

3. Mute Footswitch

Allows the mute function to be controlled by a latching footswitch (such as the FS-1)

4. FX Loop Send A

Connects Channel A to the input of an effects unit

5. FX Loop Return A

Connects the output of an effects unit to Channel A output

6. FX Loop Send B

Connects Channel B to the input of an effects unit

7. FX Loop Return B

Connects the output of an effects unit to Channel B output

8. Line output

Mixes both channels for a mono unbalanced 1/4″ output Jack

9. Main Output A

Individual balanced XLR output for Channel A

10. Main Output B

Individual balanced XLR output for Channel B

11. 12V DC

2.1mm DC Jack for connecting the supplied 12VDC centre negative power supply


Channel A Input Impedance2.2 MΩ
Channel B XLR Input ImpedanceMinimum 6 KΩ
Channel B Jack Input Impedance2.2 MΩ
FX Send Level-10dBu
FX Send ImpedanceLess than 150 Ω
FX Return Level-10dBu
FX Return Impedance10 KΩ
Line Output Level-10dBu
Line Output ImpedanceLess than 150 Ω
Main Output Level.+4dBu
Main Output ImpedanceLess than 60 Ω
Power Supply12 VDC Centre Negative
Current Draw750 milliamps

Fuses & Valves

VALVE1 x ECC83/12AX7

HT FUSET63 milliamps