Sound Devices 688 firmware - (v3.00) provides a stability and performance update for previously released versions. This firmware includes new features related to automixing, RF scanning, and frequency assignment.

688 Firmware version 3.00 is now available for download.


Dugan Automixing   Variable Off-Attenuation   RF Scanning via SL-6   Lectrosonics SRc Support
Dugan Automixing
  Variable Off-Attenuation   RF Scanning via SL-6   Lectrosonics SRc Support
The 688 now offers 12 channels of automixing with the Dan Dugan Speech System™.   The 688's MixAssist auto mixer now lets end users define the amount of off-attenuation.    SuperSlot receivers, can scan the RF spectrum, display results & enable frequency assignment.   The 688 and SL-6 now support Lectrosonics SRc, a SuperSlot-compatible receiver.

It is highly recommended that users update to the latest version of firmware available as soon as possible.

Download the available  688 User Guide. It is up-to-date with all relevant features and functionality changes provided in the latest released versions of firmware.


Full Detail - Features and Changes

Last update April 18,2016

Changes introduced in 3.00 include:


  • 12-channel automatic mixing with Dan Dugan automixing.
  • MixAssist now allows control of the Off-Attenuation setting. Range is 6 dB to 40 dB in 1 dB increments.
  • SL-6 supports Lectrosonics SRc.
  • The SL-6 supports RF Scan with Wisycom and Lectrosonics SRb & SRc SuperSlot-compatible receivers, which includes:
    • Ability to scan the entire receiver frequency spectrum and display detailed results on the 688's larger, colorful LCD.
    • Use the Select encoder to zoom in and out; Use the Headphone encoder to horizontally scroll through the scan and assign a selected frequency to available receiver channels.
    • Wisycom RF Group Scan from the Wisycom Rx screen: Initiates scan and lists channels for the selected group by returned dBuV values.
    • Lectrosonics RF Scan from the Lectosonics Rx screen: Scans the frequency range of the receiver, displays results, and enables frequency assignment to the receiver's available channels.


  • CL-12 Fader Calibration now also includes a fader down calibration.
  • Relocated Compatibility on (SL-6) Lectrosonics SRb Rx screen to the SRb menu.


  • CL-12 MixAssist LEDs on channels 10-12 do not show correct MixAssist activity.
  • Unable to use SL-6 Rx Screens to scroll through Lectrosonics SRb user-defined tuning groups U and V.
  • Missing support of Lectrosonics Block 606.
  • Sluggish navigation in the SRb Rx Screen Menus.

Known Issues

The list below are the published known issues for the latest 688 Firmware.

  • SL-6 RF Scan does not complete correctly when three Wisycom MCR-42s are in use.
  • The CL-12 does not always initialize when connecting to the 688 if the CL-12's DC Boost Input is connected. 
    When disconnecting the CL-12 from the 688: Remove the DC Boost Input micro USB cable before disconnecting the CL-12/688 USB A to USB B cable. When connecting the CL-12 to the 688: Connect the CL-12/688 USB A to USB B cable before connecting the DC Boost Input micro USB cable.
  • Rare issue where the system clock gets set to an invalid date. This can cause the daily folder to be incorrectly named and therefore the files get stored in the wrong folder. As of V2.00+, if the 688 detects an invalid date, it will display the following message: “System date error detected. Please reset time and date.”

 Please click HERE to download 688 Firmware v3.00

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