Surprisingly all of Athern's big unusual prototypes like the Turbines and now the U50s have been very popular, so it follows that most buyers would also invest in sound. Many sound decoders were sold by QSI and Soundtraxx for the Turbines so both manufactures are doing the same for the U50s.

Here is a copy of Soundtraxx's release information:

New! Tsunami TSU-1000 for the U50

In response to the recent release of the General Electric U50 model from Athearn Trains, we have released our new U50 decoder. This prime mover is a Dual GE FDL-16, which can be used for both the U50 and U50C!

The U50 is a doubleengined version of the U-series units which could be seen along the UP and SP mainlines throughout the 1970s.

The new TSU-1000 is a versatile 1 Amp decoder integrating a full featured sound system, four Hyperlight lighting effects, a motor controller and a DCC decoder in one, and easily adapted for use in the Athearn U50.

These decoders are in stock and available for ordering now! Please reference P.N. 827124 when ordering. Airhorns included are: Wabco A2, E2 Leslie A125, A200, S2M, S3L, S5T Nathan K3L, M3, M5, P3, P5 (Early) Holden M3H, K5H Hancock Air Whistle TSU-1000 827124 TSU-1000 for Dual GE FDL-16

MSRP $119.00.

Here is the info from QSI Titan-U U50 Stereo Sound Decoder