Hardwiring sound decoders into kit built loco`s

I have been slowly fitting DCC sound to my kit built stock since 2012.  I have been lucky enough to have discovered Zimo sound decoders and consider these to be the best so far…….Most of my 4mm locomotives have been fitted with the Zimo MX648.

Starting with my 7mm locos I have fitted these with the ZIMO MX645 as these are quite adequate for the modern motors  that are fitted in my stock.



https://www.youtube.com/watch?v=7-EcYyc7ks8

Sound file and decoder is from Youchoos andis based on the real thing….I use the NCE Powercab.

Hi John,

Hard-wiring - as in red/black directly to track pick-ups, orange/grey directly to motor terminals?

Nigel

Yes Nigel………………………………………………………….
I discovered that there are few problems with hardwiring Zimo decoders.    I am not an expert, just a confident enthusiast.

This particular model was built in 2010, way before I had considered fitting DCC sound.

The first task    was to establish the ampage requirements of the modern motors I use.   Mashima,  Maxon, Canon and Sagami.

These draw less current than some 4mm models.

They draw less than 0.5amp working normally and often less but no more than 0.8amp when stalled.

Hence the Zimo MX645 which is rated at 1.2amp (2.5peak) plus it`s 3amp amplifier is more than adequate for my 7mm locos…………..    providing there is no electrical shorting   …………..

The second task,  therefore is to check for potential electrical shorts…… that must count as a risk assessment in modern parlance !!!????

my locos are all metal so risk areas are :-


metal brake shoes touching the drivers

wheel guard irons touching the track

sandpipes touching the track/wheels

power pickups touching the frame etc

wheels touching the chassis frame

exposed wiring touching what it should`nt

decoders and their speakers shorting out against the model itself.

obvoiusly if the model is runnung perfectly fine before you start you are almost there………..



The third task is to adjust or insulate all risk areas………….




I always label the wires from motor and pickups………….in case I`m called away and then get mixed up !!!!


Then , as you say Nigel, follow the instructions given with every decoder…………………




red and black wires to the pickups (track)

orange and grey to the motor.

purple and purple to the speakers of your choice

( the Youchoos decoders I purchase have a stay alive capacitor already connected to the decoder )

I never solder any wires directly onto the decoder as It`s a recipe for disaster










So there you have it…..    six wires from the decoder to solder up making sure the connections are insulated with heat shrink tubing.






I use these plastic cased reflex based speakers to avoid electrical shorts against the loco `s metal body








And exactly the same procedure for a re wheeled, improved coupling rods and a fitted Zimo MX648 decoder and sugar cube speaker  BACHMANN 4mm RTR tank loco.

Hi John,

So these decoders do not come with pin terminals already connected? (6, 8 or the millipede PLUX). No experience of Zimo decoders, hence the question. Just checked the 645, no plug. I never let a soldering iron anywhere near a decoder, board or wires, especially an expensive sound one. Only exception used to be the speaker wires, and now I've switched to using micro-terminals (mini-terminal blocks) and micro-2-pin connectors so that the decoder can be removed without touching the speakers (or vice versa), as it's a darn sight easier when wiring 2 or more speakers to the same decoder.

Nigel

Hi Nigel
Yes they come with 6 and 8 pin plugs, which of course I cut off. Some are 12 pin.

John

Hi John,

I use female wiring harnesses (6, 8, 21 pin, yet to do a PLUX pin-out), which obviate the need for hard-wiring a decoder. If it comes bare-wire I use screw terminals.

Nigel

 Today I finally got round to fit my Johnson 1P tank loco with a Zimo MX645 sound decoder with Digitrains 2 cylinder lightweight  Multi-drive steam sound…………………………..

I think 7mm does deserve sound.  Most of my 4mm BR era locos have sound which are great.  They are costly though and if you have have one sound equipped loco you really need them all to have sound.

I have the Dapol 08 on order and I believe it will have a Zimo sound system.  I also have the Little Loco Cl 15 on order and have arranged to have my model equipped for sound - Zimo as well.

John

Yes they are costly John, but well worth the outlay.  It adds a whole new dimension to modelling and steam sounds are slowly getting better.  I searched the web and Youtube to see whats about which helped.  Some modellers struggle to get the sound to  match the wheel rotation and how the real thing sounds when working.  I can just about remember watching the very last of steam when a teenager…………………….

Anyhow,  I completed  `sounding up` my LMS shunter this week.  ( I sold some 4mm stock to fund it)

Zimo again and a J94 soundfile from Digitrains with Paul Chetter`s Multidrive sounds.



https://www.youtube.com/watch?v=ylO_Pd0pzj4






But to restore the equilibrium I must add my favourite 7mm build and loco……….

GWR…… Dukedog….. from a Javelin kit with Youchoos sounds from Preserved 9017………………














 

very nice ,I like the radio voice,very authentic,,
:thumbs :thumbs ;-) :cool:
Owen

[user=1681]Silver Fox[/user] wrote:

very nice ,I like the radio voice,very authentic,,
:thumbs :thumbs ;-) :cool:
Owen

Owen,

Thanks for the appreciative words.

It should be authentic, this shunt actually happened whilst I was recording the loco.

Not as local to you as you may think from the accent - it was at Eastleigh yard.

Kind regards,

Paul