The Drop-Ins were originally designed to use the Phoenix P8 sound module. However, with the addition of the new XDRIVE board, you can now use a different vendor's sound decoder. Any NMRA-DCC compliant sound decoder can be used although Soundtraxx is recommended. The XDRIVE comes complete with the required plug-in harness along with a cable to connect to the sound decoder. Fits all Drop-Ins except the S4.

If your Drop-In is an S4, be sure to get the XDRIVES4 version. It uses a different harness configuration. The price is the same.

XDRIVE......Drop-In External DCC Decoder Driver with Standard Harness and Connectors