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Train Control Systems WOWDiesel sound decoder

Read this review from Model Railroader magazine
WOWDiesel sound decoder
Whether you need sounds for an HO scale FT or an SD70, the diesel version of Train Control Systems’ WOWSound decoder has you covered. The WOWDiesel Digital Command Control sound decoder features microSD card technology with enough storage space for full CD-quality audio files.

Installation. The decoder measures .22" x .66" x 1.35", and the KA-2 “Keep-Alive” capacitor measures .347" x .458" x 1.296". The KA-2 and speaker wires are connected to a wiring harness that fits into a seven-pin plug on one end of the decoder. The WOWSound 8Ω speakers are available in .8W, .79" (20mm) round; 1W, 1.1" (28mm) round; and 1W, .63" x 1.37" (16mm x 35mm) rectangular sizes.

Using a nine-pin to eight-pin harness (sold separately), I installed the decoder, KA-2, and an WOWSound 1.1" speaker into a Kato HO scale Electro-Motive Division F40PH. For another installation example, see DCC Corner on page 62.

Programming. Pressing function 8 four times triggers Audio Assist mode, in which voice prompts guide the user through some programming tasks, including function mapping, choosing sound and lighting effects, and adjusting individual volume levels. The best part about Audio Assist is that I don’t have to look up and enter individual configuration variable (CV) values.

Audio Assist isn’t available for every feature. Many advanced settings require four-CV programming, using CVs 201, 202, 203, and 204 in sequence. TCS provides a free online programming tool on its website to make this task easier.

Other non-sound features, such as adding momentum or changing the address, rely on conventional programming. A programming guide and WOWSound user manuals are available as free downloads at

Operation and sound. Using Audio Assist, I chose the turbocharged 645 prime mover for the F40PH, and it sounded like a prototype recording.

There are three throttle modes available that can be selected via Audio Assist. In traditional mode, the throttle controls the train speed and braking just like any other decoder. In manual-notching mode, function keys control engine rpm sounds independently from the locomotive speed. In Prototype Mode, which is the default setting, the brakes are controlled by function keys independently from the throttle setting.

Prototype Mode is a standout feature. In addition to using back-electromotive force (BEMF) control to keep the speed constant, in prototype mode the decoder measures BEMF to adjust the prime mover sounds. After easily setting up this feature with Audio Assist, the rpm sounds automatically notched up or down according to the load. Independent of speed, the engine will ramp up when starting a train, then notch down when the train gets under way.

Function keys control the six lighting outputs in light mode and the sound effects in sound mode. The headlight function works in both modes.

Sound functions include the bell, long and short horn blasts, and grade crossing signals of varying lengths. There are a wide variety of air horns to choose from including those from Nathan, Leslie, and Wabco.

Pressing function 5 triggers a working dynamic brake. I heard the dynamic brake fans come on, and the engine drop down a few notches. Then the locomotive began to prototypically notch up as it slowed down with each key press.

The WOWDiesel supports advance consisting and includes CVs 19, 21, 22, 23, and 24 to adjust the consist address, function control, and momentum. Although Audio Assist does include a Speed Matching feature, I found it of limited use, as it simply adjusts the forward and reverse trim.

Throughout testing, the sounds and lighting remained constant thanks to the Keep-Alive unit. These capacitors provide several seconds of power to ensure that the sounds remain uninterrupted.

For those looking for a DCC sound decoder for an HO scale EMD locomotive, the WOWDiesel with Keep-Alive and a TCS WOWSpeaker is a winning combination.
Price: $109.95 (with Keep-Alive), $94.95 (decoder only), $9.95 (WOWSpeaker)
Train Control Systems
P.O. Box 341
Blooming Glen, PA 18911
▪▪44,100 samples per second at 16-bit resolution
▪▪Prime mover sounds include EMD 567, 567 turbo, 645 turbo, 710 turbo
▪▪Six lighting outputs
▪▪Effects include 31 horns, 34 bells, and 19 lighting options

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