deserves separate mention since it is such a versatile and
complex system. There are four types of sounds used on the
Conventional DCC decoder sounds, normally used in a
locomotive to produce engine noises, bell, horn, exhaust
sounds and all the standard functions.
Hardware-generated sounds which are special electronic
modules designed specifically to produce a certain sound
effect to be played by a speaker which is usually on the
Train Technologies (ITT) makes a product line of
electronically produced sounds and these can be activated
by wiring them to a speaker and turning on the power to
the module. This includes railroad crossing bells sound
which can be wired to a small speaker on the layout near
a crossing and is typically used together with an LRT Grade
Crossing Pro which produces the flashing lights to accompany
the crossing bell sound effect.
Rail Technologies (LRT) makes a product line which
includes grade crossing animation (flashing lights, train
detection), and many other items.
Computer-produced sounds are sounds that are recorded
and translated to a .wav format and played using JMRI through
the computer's sound system.
RHJ Rail, this is a whole subsystem which
uses the sound card line-out to connect to a custom designed
sound distribution board which, in turn, uses a number of
DCC-activated relays to connect the sound line to a specific
speaker or set of speakers on or under the layout.
Telegraph sounds are, at present, of two types.
the first type, a telegraph message is sent to a real telegraph
device, recorded (on a smart phone), copied to a computer,
translated and edited to a .wav file and played through
System 3 above.
the second type, a DCC decoder is used with special scripts
to translate a written text message to Morse Code and play
that message using a standard (non-sound) DCC mobile decoder
by rapidly flashing an auxiliary function output of the
output would normally be used for something like the headlight
or marker lights on a locomotive but for this purpose, it
is used to drive a fast-responding relay. This small relay
can be used either inside a station on the layout, where
the relay is pressed hard against a wall of the station
to amplify the clicking sound it makes when turning on or
off, or to drive a larger-current device such as a real
turns out that a JMRI script can turn a decoder function
on and off much more quickly than can a hand-held throttle,
thus a sequence like a Morse Code signal can be created
effectively at a speed comparable to the real thing.
has to wonder, how many DCC model railroads have a working
telegraph system, especially one with a real telegraph device
as one of its options?
set-up for Digitrax DCC Sound Layout
facilitate in the automatic operation of special effects,
including sound, several custom-designed gizmos have been
developed. Except for the Sound Control Board (SCB), these
are based on mobile decoders and relays. Standard effects
which operate by just turning something on and off typically
use a Decoder Relay Board (DRB) which is described on Technical
- Page 5.
Control Board (SCB) - This is a special board that uses
input from a computer sound card (line-out) and it can adjust
the volume and provide amplification. This was made from
an inexpensive (free) pair of computer speakers by removing
the controls found on one speaker of the pair and mounting
them on a board under the layout convenient to the computer
sound output. This board then provides sound output to a
sound distribution board, DRB-S, for deploying sound around
Relay Board-Sound (DRB-S)
- The DRB-S is a special version of the standard DRB. The
sound version simply uses both poles of the DPDT relay to
provide the capability of stereo sound being distributed
around the layout.
- Page 7
details on any of the above can, of course, be obtained
by contacting RHJ