Sigma AMP5 - 5-Channel Power Amplifier


The Sigma series AMP5 is a 200W/Ch five-channel amplifier derived from the AMP2, but with necessary part and layout changes to accommodate its five-channel architecture. Like the AMP2, it utilizes switching technologies for both power supply and amplification stages.

A Classé-designed switch mode power supply with Power Factor Correction makes over 1,000W of clean and stable power available while being both compact and efficient. A new class D amplifier topology provides wide dynamic range, smooth and extended frequency response and rich harmonic detail to yield stunning sonic performance. The efficiency of class D adds efficiency, low heat dissipation and relatively small size to the list of the AMP5’s attributes.


All tests un-weighted and 20Hz - 20kHz measurement bandwidth used.
Frequency response 10Hz - 20kHz, -1dB into 4Ω
Output power 200W rms into 8Ω All channels driven
400W rms into 4Ω Any two channels driven*
Harmonic Distortion 0.018% @ 1kHz All channelsdriven
to 1/8th power into 8Ω
Peak Output Voltage 113V peak to peak, 40V RMS no load
113V peak to peak, 40V RMS into 8Ω
Input Impedance 100kΩ Balanced / 50kΩ SE
Voltage gain 29 dB
Input level at clipping 1.4Vrms Balanced/SE
>80 dB below fundamental into 8Ω SE
Signal to Noise Ratio -100 dB at peak output into 8Ω (AES17)
Rated power
200W @ 1/8th power into 8Ω
Mains voltage 100V - 240V, 50/60Hz
Overall Dimensions Width: 17.00" (433mm)
Depth (excluding connectors): 14.57" (370mm)
Height: 3.75" (95mm)
Net weight 23.1 lb (10.48 kg)
Shipping weight 30.0 lb (13.61 kg)
*each channel supports 400W output into 4 ohms but the AC Mains/power
supply cannot support all channels driven simultaneously at this level, which
would require over 2,500W and only occur under a special test condition.
Every channel easily drives lower impedance loads.

Product Info Sheet

Sigma AMP-5 - Product Info Sheet - English | Français


  • Latest Firmware : Version 0.57 (Date: Jan 1, 2017)
How to Check and Update Firmware

How to check the current Firmware of your Sigma AMP

  • If the Sigma AMP is connected via CAN-Bus (to a SSP), you can check the installed Firmware Version using the Status Screen of your Classé Surround Sound Processor.

  • If you have no CAN-Bus connection to verify the Firmware Version then we advise you update the Firmware using the Procedure below in any case.  It will take only a minute.

How to update  Firmware on a Sigma AMP (all models)

  • download the latest Firmware package
  • unzip the downloaded file on your local computer
  • copy the unzipped file onto a new USB key.  This key must be empty.  The file must be located at the "root" level
  • power off your Sigma AMP using the Power switch on the rear of the unit
  • insert the USB stick in the front USB port
  • Power on the Sigma AMP using the power switch in the rear of the unit
  • the Firmware update will start automatically and will take less than a minute
  • When finished the unit will go into Standby (solid red LED)

What to do when your Firmware Update fails

  • simply power down the unit and remove the USB key, the unit will revert back to its previous Firmware Version when your power on again;

    Then what...?

    1. Our first suggestion is to try again using the same USB key;
    2. If the Update Fails once more, we suggest that you get a new, clean USB key and try again. We have seen updates fail because of fragmentation of the USB key, or because of vendor-specific key issues.
    3. If the Update still fails, we ask you to send us the APP.LOG and BOOT.LOG files that you will find on the USB Key:
      - insert the USB key into your local computer and open the USB key (file explorer)
      - you will notice that 2 LOG files have been written to the USB key.
      - Copy these log file to your local computer. 
      - Please send them to Classé Tech Support for further evaluation, with the Serial Number of the unit.


Owner's Manual

Installation Tips

  • All Sigma AMPs can either be installed "Stand Alone" or in a 19" rack.  The side panels have been conceived in such a way that, when inverted, they serve as solid rack-mounting ears for installation in a 19" rack.  See pages 5 and 6 of the Owners Manual;

  • Make sure that the Sigma AMP has clearance in the back for the attached cables;

  • We also suggest to position it well away from source components and preamps/processors that may be sensitive to Electromagnetic Fields;

  • Do not connect and disconnect speakers on ANY amplifier whilst the unit is switched on, in order to avoid unpleasant and potentially damaging DC (Direct Current) Noises and short circuits.

Home Automation

Sigma AMPs can be controlled in a number of ways other than using the Front LED Button. The Rear Panel offers CAN-Bus, IR-in-out, a separate DC Trigger port and RS232. The latter is available via a RJ-45 connector on the rear panel.

IR Remote Control Codes

RS232 Protocol

Sigma AMPs can be controlled using RS232, a protocol used by Home Automation Systems like Crestron, Control 4, etc.The Sigma AMP is equipped with a RJ-45 port for this purpose.

Event though the RS232 connection is made using an Ethernet cable, the actual signal is not "RS232-over-IP", but a standard RS232 signal. For control systems equipped with an (older) DB9 output port, you will need to use a DB9 (female) to RJ 45 (female) adaptor.  See the Sigma AMP Owner's Manual.



CAN-Bus stands for "Controller Area Network (CAN) Bus".  Classé's implementation of CAN-Bus allows for communication and control between Classé components.  All you need is to connect the CAN-Bus port as a "daisy chain" and make sure the last unit connected has a "terminator" on the CAN-Bus out.

Note that some older Classé equipment may not recognize more recent Classé Models via CAN-Bus. In case of doubt, please contact Classé Techical Support.

IR Trigger


The IR in and output port allow for an electrical IR signal to control the "standby" and "operate" mode on a Classé Amplifier.  This is not an infrared signal, but a electrical signal obtained by using standard IR receivers, distribution amplifiers, and emitters (available from your dealer) that will translate the remote’s flashes of infrared light into corresponding pulses of electricity.

DC Trigger


Classé Amplifiers will consider the constant presence of a 5V-12V DC signal on the DC input as an "operate" signal.  The unit will go into standby when the DC voltage is absent.

Wake-on-LAN, Auto Standby and Global Standby

Some customers and installers are taken by surprise when a Sigma unit, or multiple Sigma units, shuts down by itself, or when a Sigma unit does not power on when a network command or CAN-Bus command is sent.  This behavior is the result of the interplay between three features: Wake on LAN, Auto Standby and Global Standby.  

We herewith explain these features and indicate how each of them can be changed.

Wake-on-LAN (WoL)

All units that ship to member countries of the European Union have Wake on Lan DISABLED in order to comply with European "Standby Power" Regulations.  That means that the unit will not react to Network nor CAN-Bus commands once it is in Standby; the Communications Module is inactive.  This can be changed using the Front Panel LED button (See below).

Auto Standby

All Sigma AMPs worldwide ship with Auto Standby ENABLED.  This means that the amplifier will go into Standby (power off) if there is no (significant) audio signal for approximately 15 minutes.  This feature can be disabled using the Front LED Button.

Global Standby

All Sigma AMPs worldwide ship with Global Standby ENABLED.  Units that have Global Standby enabled will work as a "collective": if one unit goes into Standby, the other units that have Global Standby enabled will follow. Also, please note that this feature will be reset to ENABLED with each Firmware Update.

How to change these settings on a Sigma AMP

A. How to enable "Wake-on-LAN"


This must be done manually, using the Front LED Standby button of the Sigma AMP.

  1. The first step is to activate the "Configuration Mode" using the Front LED button:

    While holding the LED button depressed, plug in the AC power cord. Once the amber or green LED comes on, let go of the button (make sure you can actually see the light of the button, so put your finger halfway). Do not let go too quickly otherwise the unit will default to standard operation.  If you see an alternating Green and Amber LED, you have successfully entered the Configuration Mode.
  2. Once in Configuration Mode, the LED indicates whether each feature is enabled (= solid) or disabled (= flashing).

    Wake on Network = Amber LED
    flashing = disabled, solid = enabled.
  3. To change from flashing to solid, wait until the color lights up, then press the LED button once and let go. You have now changed the status.
  4. In order to verify the new Status, wait until the LED passes by again.  It will now indicate the new Status.
  5. To return to normal operation, simply disconnect and reconnect the AC Power Cord.

B. How to DISABLE Auto Standby


This must be done manually, using the Front LED Standby button of the Sigma AMP.

  1. Enter the Configuration Mode using the procedure mentioned above in A1.
  2. The Green LED indicates the Status of Auto Standby. Flashing = disabled.  Solid = enabled.
  3. To change from solid to flashing, wait until the color lights up, then press the LED button once and let go. You have now changed the status.
  4. Follow Steps 4 and 5 outlined above.


C.  How to DISABLE Global Standby


This must be done using the CAN-Bus feature of the attached Classé Sigma SSP or CT-SSP/SSP-800.

  • Sigma SSP
    From the MENU, select STATUS > click RIght Arrow at the top > The CAN-Bus devices now show on screen > Select the unit
  • CT-SSP/SSP-800
    From the MENU, select System Setup > Status > More > select unit > configuration.


  • All Sigma Series products can operate on AC Voltages between 110V - 240V.  
  • Make sure to change the AC Fuse (rear) to match the AC Voltag e of your country. 


  • All Sigma Series products  have one AC Fuse accessible via the rear panel;
  • Make sure that the AC Fuse corresponds to the AC Voltage offered;

When you change the Fuse to accomodate a different AC Voltage, please contact Classé to obtain a new sticker for the back of your unit indicating the new AC Operating Voltage.

Fuse Specifications - Sigma 2200i, AMP5, AMP2, AMP MONO

  • For 100-120 Volts

Fuse Value: T6.3AH 250V 
Description: IEC time lag, high breaking capacity, 6.3A 250V

Classé Part No. 51764877-00 0
Schurter Part No. 0001.2512
Littlefuse Part No. 21506.3


  • For 220-230-240 Volts

Fuse Value: T3.15AH 250V
Description: IEC time lag, high breaking capacity, 3.15A 250V)

Classé Part No. 51764794-00
Schurter Part No. 0001.2509
Littlefuse Part No. 2153.15

Drawings 2D/3D


  • Classé Product Brochure - English

Info Sheet

Sigma AMP5 - Info Sheet - English | Français


Your Classé Sigma unit has a 5-year Limited Product Warranty on Manufacturing Defects that covers both Material and Labor.

  • Please note that the Classé Limited Warranty is only valid in the Country of Purchase.
  • Please make sure to keep your original Purchase Receipt.
  • The 5-year Limited Warranty is transferable to a next owner. When selling your unit, please hand the original purchase receipt to the next owner.

In case you reside in a Country that does not have a national Classé or Bowers and Wilkins Distributor, please contact one of our three global Service Centers (Hong Kong, United Kingdom or USA) to discuss Warranty Service.

Warranty Date Dispute 

If you do not have your original purchase receipt anymore, Classé will use the Factory Shipping Date as the  Purchase Date to determine Warranty Status.


In the unfortunate event that the unit develops a problem we advise you to follow the procedure below

  • Make sure the unit has the latest Firmware.  Does it solve the issue?
  • Try and find your answer on this website
  • You can submit a question on-line, call your local Classé Dealer or contact a Classé Service Center directly
  • Should the defect require repair, a Classé Service Center will send you a Return Authorization which you can use to ship your unit
  • Please do not ship a unit to a Classé Service Center WITHOUT Return Authorization 

Upgrade Kits

There are no Upgrade Kits available for this Model.

Replacement Shipping Box

A replacement Shipping Box can be ordered with Classé. The box is made out of Coroplast®, which is a strong and waterproof material.  Semi-rigid foam inserts ensure the best possible protection during storage and transport. Please inquire with your local Classé Dealer or contact Classé directly.

*) For shipping Legacy units (made before Delta I series) we recommend using the original box if still intact, and to put this box with at least 2 inches of semi-rigid foam into a new corrugated box.

PCB Replacement Boards (click on the Header to sort)

R8601-04-01A Sigma AMP Digital Power Supply Board
R8706-02-00S Sigma-Amp5 Channel output filter board

Cosmetics & Individual Parts (click on the Header to sort)

51138601-00 Delta RoHS Can Bus Terminator
51554245-00 USB KEY
51705631-04 FACEPLATE AMP2/5/MONO
51765528-07 BASEPLATE AMP5
51765601-07/-08 INNERWALL AMP5
51767920-03 ADD-ON AMP5
51684430-04/-05 TOP COVER
51685676-03 COVER BRACKET
51749209-05 SIDE BRACKET
51685189-03 STANDBY BUTTON
51685262-01 LED PIPE