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Bachmann NRM Prototype Deltic

Sound Decoder Installation
by Doug Teggin

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Click here
for the historical information and review of the model

with installation of a standard DCC decoder.

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We were all impressed with the Bachmann model of
the Prototype Deltic locomotive commissioned by the NRM.

As some people prefer to sell on their models for
profit, others who keep theirs in a cupboard to gain some value, other who may
have their model on display on the nice NRM Perspex base you will have some
modellers who are running theirs on their layouts. Better still, you will have
some people install DCC decoder into the model to get the best running
characteristics out of it. Here I go a step further and install a sound decoder
into the model.

I'm no expert in sound decoders, their selection,
programming and installation so enrolled the help of Richard Johnson from DCC
Concepts in Australia. Richard is a renowned DCC expert who runs a business
selling and installing DCC equipment to customers around the World.

As my luck would have it, Richard had been working
on some Deltic sounds. He collects sounds from various sources and mixes them
for different models, finally uploading the sounds into the ROM chips on the DCC
sound decoder.

Here is a video clip of a few Deltics, filmed in
1999. The sound is particular as you will notice:

Richard explained that the Deltic sound was very
particular as the prototype had a twin 18-cylinder engines and the sound it made
was phenomenal. A very difficult task to replicate in a model locomotive. Anyway
we worked on this and put a decoder together. What we have here is work in
progress. It will be improved and further developed. In the mean time we have a
decoder that is now commercially available so owners of this model can enjoy it
in their Deltic models.

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The decoder used is a ESU LokSound 3.5 decoder.
This decoder offers all the great DCC features that are expected from ESU. It
can be bought pre-loaded with specific or generic loco sounds or you can load
the sounds yourself using the ESU LokProgrammer. This is how we have managed to
get the Deltic sounds onto the decoder. You can purchase the LokSound decoder
directly from Richard with the Deltic sounds pre-installed. You just have to fit
the decoder.

Installing the Sound Decoder

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This particular LokSound 3.5 decoder came with an
8-pin NEM plug so I had to use a 8-pin to 21-pin adaptor. in future, both 8-pin
and 21-pin LokSound 3.5 decoders will be available.

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You can't go wrong with the 21-pin adaptor, it
only fits one way round. Socket #1 of the 8-pin part is clearly marked and you
match up the orange wire of the decoder to this corner.

We see below the standard speaker and speaker
housing that is supplied with the LokSound 3.5 decoder. It could be used if you
wish. Just secure it in place with some blue-tack or UHU U-tac (yellow).

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The standard speaker is housed in a plastic round
box. To get the best deep-sound results from this, the vents around the side
should be blocked up with blue-tack. For this setup, I have used two of these
23mm speakers wired in parallel and I'm building a custom speaker box so I
remove the plastic boxes by carefully prising the speaker from the box with a
small screwdriver.

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It is best to measure the space available so you
don't end up with a box that is too big for the space available.

There is a 10mm height restriction inside the
cavity as there are the fans to consider. You can't build the box too high. Here
are a couple of photos of the dimensions so you can see the space limitations.

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I am building a speaker box from balsa and
plywood. The ply is 3-ply 1mm thick and the balsa is also about 1mm in
thickness. To strengthen the wood, you can brush it with thin superglue (Cyano)
that will soak into the wood, and improve the resonance of the box.

I've marked out where the two speakers will go. I
drill out the speaker openings with a small drill and then I fix the two
speakers to the top piece. They are secured with a universal cement that is
applied to the back of the speaker and the surrounding wood once the speakers
are in position. Don't use superglue as it will seep into the speaker under the
metal rim and probably mess up the sound.

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You see below that I have made a base, installed
the sides that are glued to the base. I've filled the seams with UHU-tac to
prevent any air getting into the box. The top goes on. Cyano on the wood to wood
joins and universal cement to the metal to wood joins. End pieces of the box are
then glued on.

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I've build it like this as the space was tricky.
some pieces had to be measured once others were in place. I can pop this box out
if I now wish. The UHU-tac comes off easily.

You have to make sure that the screw pillars are
free to go around the box. I lightly made some space for them on my one.

So you see in the photo below, the box is
complete. It is airtight behind the speakers and the resonance of the box is
reduced by using UHU-tac to secure it to the body. I did notice when testing the
decoder with the round plastic speaker that the vibrations of the box were very
audible. Reduce those and the sound quality improved dramatically.

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So what does it sound like and what special sounds
lurk within this little decoder?

Well I was impressed. The quality of this sound is
better than any sound I have heard to date on any Bachmann loco that I have
listened to or any other locos that I've seen at shows and Toy Fairs. This one
with the custom sound box is fantastic.

The video doesn't do the decoder full justice. As
it is compressed for YouTube, the full range of frequencies are lost.

See and listen for yourself:;glow:FFFFFF;foreground:333333;special:FFC300;&related=1

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DCC Concepts configuration of the ESU LokSound 3.5

Information from Richard Johnson of DCC

Engine Sound:

The current engine sound set works really nicely and captures some of the
complex resonances of the “Deltic” sound but still (to us anyway, we are rather
fussy) lacks a wee bit of the “energy” that is very hard to achieve with the
size of amplifier and speaker used in small Scale sound decoders. We are
currently working on a possible enhanced set however this will be some weeks
rather than days: (it will be a free re-load if we release it – see our note
below please).


We have not settled on a horn we really think sounds right so I have included
two differing sounds for this – a hi/low and single tone type.

Station announcement:
We really like this sound-file very much and it can add lots of layout
“atmosphere” if played with the loco in a station area with loco sound otherwise

It is adapted from a real Birmingham New Street
announcement modified to remove any train franchise names so it is generically
usable for most modelling periods. Lots of echo and reverb added to give that
typical almost non-directional “sound from everywhere” of the PA system.

If at all possible use TWO speakers in parallel – this will double the
available amplifier power. The result of this is a small volume increase and a
large increase in the “energy” of sound delivery. It is worth removing metal to
achieve this!

SEAL the enclosures if using the 2x 23mm speakers
supplied. (That means totally airtight…imagine they are full of poison gas or
anthrax – THAT is how little air must escape for best performance).

Using two ESU enclosures will be fine although to
us the BEST result will be from both speakers in a custom box and mounted very,
very close together – ie the rims virtually touching. This box can be made of
many materials including stiff card if you find it easier. Before installing the
speakers, seal all joints perfectly and paint the WHOLE enclosure inside and out
with thin superglue or shellac/epoxy/varnish – this will soak into the card and
make a very stiff, very hard box.

Once this is done and it is properly dried, check
for/fix any tiny leaks and than add the speakers using a very thin film of
silicone around each speaker rim. Make sure there are NO pinholes anywhere where
air can leak…None at all! They will cost clarity, volume and lower speaker power
handling. Leave overnight to dry before testing sound!

F0 Lights on
F1 Sound on
F2 Horn #1
F3 Horn #2
F4 Whistle
F5 Vacuum / air release & Coupler sound
F6 Station announcement (see notes above)
F7 Rail Click (Just for fun… this has been made playable without engine
sound so you can use it while the loco is stopped in a station and give the
impression of other trains entering the station area and crossing points etc… It
has also been made loud enough to be a reasonable background sound whilst the
motor is running/loco moving).
F8 Brake: This is automatically applied without F8 when the loco is
stopping however we added it here for manual use as it also simulates flange
squeal on curves etc quite well… for those who like real effects!
F9 Vacuum release
F10 Alternate horn

Please do feel free to make comment or suggestions
for improvement, or tell us what or where more needs to be done.

Available now as follows: LokSound V3.5 with 23mm speaker & 8 pin plug &
Deltic sound file $AU199.00 (£92.20 or 120.17 EUR - exchange rates as
of 14 March 2008

**As an exclusive offer
for Model Rail Forum Members only**

The price is still $AU199 – but we will include a second 23mm speaker OR a 40x20mm OVAL speaker
and offer Free Postage worldwide!

Payment: We accept credit cards (Amex, MC, Visa or
associated cards), Internationally enabled debit cards or PayPal. Direct bank
deposit is available within Australia – please ask for our details at time of

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We offer a “free reload” service” for all sound decoders
purchased from us so will happily re-programme any sound decoder with this new
“Deltic” sound file if the decoder is returned to us and $AU5.00 is deposited
into our PayPal account to cover return postage (Same post cost worldwide – all
decoders shipped airmail).

If your
sound decoder was purchased elsewhere we can still load it for you, however the
cost will be $AU15.00

either case, if the decoder does NOT have an 8 pin plug we charge an added
$A5.00 as “plug free” decoders require added labour for connection prior to

(We would prefer all
payments for decoder programming costs to be via PayPal please - Email us at
DCCconcepts for PayPal account details…. We will of course also help you if you
do not have a PayPal account – please contact us for details on

[email protected]

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Many thanks to Richard Johnson of DCC Concepts for
working with us on this project. Richard and I exchanged many email and messages
on this subject and Richard has done a fine job in producing this sound 'set'
for the Deltic. He is convinced that he can produce a better sound still so
perhaps we will have an update in due course.

Doug Teggin
- March 2008

You can contact DCC Concepts via their website by clicking the banner below:



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