What is the DSX Decoder ?

The DSX is a sound only DCC operated decoder. It will not run on DC only systems and should NOT be connected to any power source other than DCC!

For a PDF file of the SoundTraxx data sheet,
CLICK HERE

For an owners' manual,
CLICK HERE

For Technical reference,
CLICK HERE

For the Diesel addendum,
CLICK HERE

To audition sounds,
CLICK HERE

The DSX decoders are specific to certain locos. In steam, you get a complete package, for example, a digital recording of the Union Pacific Challenger.  In diesel, you get a combination of a prime mover and a whistle.  An example is a EMD non-turbo prime mover with a Leslie 3 chime horn.

There are only a few connections:

• Track Power
• Speaker (using a bipolar coupling capacitor)
• optional Chuff Cam for steam use only

The DSX puts out up to 1 watt of power and is best matched to 8 ohm speakers rated from 1/2 watt to 10 watts.

 

Radio Shack
"Minimus 7" speaker

 

Tips on the SoundTraxx DSX Decoder

The "Keep Alive" Capacitor

One of the main advantages of the DSX decoder series from SoundTraxx is the ability to add a “keep alive” capacitor, which keeps the sound going and reduces “resetting” due to minor track power drop outs.

Litchfield Station sells the capacitors for this use. If space permits, Bruce recommends the 2200 uF capacitor. However, the 470 uF will help (but only about 1/4 as much, due to the lower storage capability). CLICK HERE to browse the store.

SoundTraxx provides a Technical Note on the subject. CLICK HERE to download a PDF file from their site.

However, they say that a picture is worth 1000 words. So, I’ve posted photos here of my install of a 2200 uF capacitor on a DSX. For ease of photography, the capacitor had already been soldered in place and the iron was cold - no smoke or hot tip to deal with when trying to take pictures!

Installation Tips

Here is an overview of the installation. Where room permits, Bruce likes to attach the capacitor directly to the DSX as shown. If room is tight, he attaches red and black wires to the pads and then to the capacitor, using shrink tubing. Frequently the track power leads from the DSX provide enough excess length for the purpose.

The metal piece just above the capacitor under SoundTraxx’ white shrink tubing is there for heat management and MUST NOT BE DISTURBED! Getting between that heat sink and the board to solder the wires requires a certain amount of soldering skill and a VERY SMALL iron, as shown in this photo.

Under Layout Sound

The DSX decoder can be attached to ANY 8 ohm speaker or speaker system. Since the DSX puts out 1 watt, Bruce recommends you limit the speaker to one rated in the 1 to 10 watt range. He uses a small (about 4 x 4-1/2 x 7-1/2 inch) Radio Shack "Minimus 7" speaker system from the late '80s or early '90s under his layout. He uses a 470 uF 16 volt bipolar capacitor for coupling. The input leads for the DSX connect to the track bus. Give the DSX the same address as your loco and you are running!

If you want to connect an external amplifier to the DSX and run larger speakers, check out SoundTraxx' technical notes; CLICK HERE to download the PDF file.