Digitrax HO scale DCC sound decoders have landed

New to the ever-expanding market of Digital Command Control (DCC) sound decoders is the Digitrax SoundFX. These decoders produce realistic sounds, come with a 28mm, 32O speaker, and are designed to fit newer Kato HO scale locomotives that feature fuel-tank speaker enclosures. The firm’s first three SoundFX decoder offerings are available loaded with sounds for General Electric’s AC4400 and Electro-Motive Division’s SD38-2 and F40PH.

Our sample decoder was programmed with AC4400 sounds. The decoder is designed to replace the Kato engine’s light board, and it includes two factory-installed amber-white light-emitting diodes (LEDs), which are correctly positioned to line up with the locomotive’s clear-plastic light bars. The forward LED illuminates both the headlight and the ditch lights on the Kato AC4400, so if you want the ditch lights to operate separately, you’ll need to install individual bulbs and wire them to the decoder’s two extra function outputs.

Perhaps the trickiest part of the installation was fitting the motor’s metal leads into the sockets on the decoder board. A small pair of needle-nose pliers is useful here. The decoder is secured to the locomotive’s plastic motor mount with two small screws.

The 28mm speaker snaps into the speaker enclosure that’s mounted in the locomotive’s fuel tank. The decoder also includes a 330µF capacitor, wired to the speaker. Digitrax supplies a plastic holder for the capacitor, allowing it to be easily clipped to the locomotive’s frame directly over the rear truck. Everything went together easily, and the complete installation in a Kato AC4400 took about 20 minutes.

Performance. The AC4400 decoder had a good GE four-cycle engine sound to it and operated well on both the test track in our workshop as well as on the Milwaukee, Racine & Troy (Kalmbach’s HO scale employee club layout). The decoder can play three sounds at a time, making it possible to run the engine, ring the bell, and blow the horn all at once.

A fun feature of the SoundFX decoder is the “notching” mode. The factory default changes the engine sounds automatically as the locomotive’s speed increases or decreases. However, by changing configuration variable (CV) 155 to a value of 1 or 2, you can make some or all of those changes manually. By pressing F6 for “notching up” or F7 for “notching down,” you can change the sounds of the prime mover yourself, making for a more realistic representation of a hardworking locomotive, especially when starting up a train.

Future offerings. The Digitrax SoundFX decoder is a solid start to the firm’s entry into sound decoders. Digitrax is planning to offer customizing features in the near future such as downloadable sound files, so you’ll be able to change some or all of the sounds the decoder produces. And though SoundFX decoders are designed for specific Kato locomotives, it wouldn’t be that difficult to install these decoders in other manufacturers’ engines with modification.

HO scale sound decoder

Price: Sound decoder only, $79.95

Manufacturer
Digitrax
450 Cemetery Street
Norcross, GA 30071
www.digitrax.com
Description:
Digital Command Control sound decoder with speaker and installation instruction booklet. Models are available for drop-in installation in Kato AC4400, SD38-2, and F40PH diesel locomotives.