Model Railway Forum

I’m wanting to take my first steps into sound and would like to chip a Bachmann Class 20. I had asked Rails of Sheffield (where the loco was purchased from originally) if they do a sound fitting service; unfortunately they do not, but they say fitting is normally straight forward and recommend ESU Loksound SO172-21 V5.0 Diesel Class 20 Digital Sound Decoder with speaker -21 pin, as compatible.

So, quite simple questions really;

Is it that easy, is it a case of just plugging the 21 pin chip in, or is there additional wiring to connect?
Does the sound chip need programming or once fitted it’s ready to go? (I’ve seen tutorials about programming Loksound chips using their hardware).
How do you use/control the sound, I have NCE Cab control?

I could do with a manual from that well known brand - ‘DCC sound for dummies!’ A pointer in that direction would be welcome.

I think in short, do I install it myself, or send it away?

Thank you.

Is the speaker wired to the decoder Carl, if so just plug the decoder in and fit the speaker.https://bachmann-spares.co.uk/file/E320 ... d-2019.pdf This manual will help

Hi
Firstly ensure your Bachmann Class 20 is in fact 21 pin fitting. I have the latest one and its Plux-22

You will need to install a suaitable speaker (often sold seperatly, so check) then if the speaker is seperate solder the speaker wires to the locos PCB wiring tabs. The decoder will simply plug into the socket that has the DC operation plug fitted. Just carefully leaver off the plug and fit the decoder. Its probably harder to remove and refit the body shell than fit the decoder and speaker!

Sound decoders are already set to play the correct sounds via F (function) key presses. All you need to do normally is adjust the address number to whatever you want it to become.

Dont forget most Class 20 ran/run as pairs and usually cab first.

Thank you for both replies, very helpful and has given me the clarity I needed.

My Class 20, already DCC fitted, is 21 pin. Looking at the image of the package of the suggested ESU Loksound chip it would appear that the speaker is separate, so I’ll have to solder the wires to the PCB tabs as suggested. I’m sure, with care, I can manage that.

Again many thanks.

Hi Carl,

I would suggest you might want to look at Road and Rails website or Youchoos as both show specific sound fitting guides, whilst the former also makes speaker recommendations per loco type…… for the class 20 a double iPhone speaker is suggested.

Having done a number of sound installations, the right speaker selection can make a huge difference and is worth the extra cost……. With an ESU Loksound ( v5) you will require a 4 ohm speaker.

For what it is worth, I have a class 20 with Hornby TTS fitted and with a good speaker ( 8 ohm for TTS) it is quite acceptable, especially at half the price…….. however getting these is now like hens teeth these days and they are also 8 pin so would need an adaptor for your loco.

Finally, sound and DCC places a greater burden on having clean track and so often it is prudent to also fit a stay alive but I usually ask the decoder supplier to solder on a stay alive for me as I have been the victim of fine pitch soldering directly on to the decoder and it has put me off for life.

Hope this helps

Many thanks HD.

Carl, like Hound Dog, I have mine fitted with a TTS, a small sugarcube and a homemade stay alive - that comes into its own when I use it as the pusher for my rail cleaners (as I did this afternoon).
Although Hornby have yet to announce when they will release a class 20 soundfile for the HM7K system (they have been inundated with requests for that particular profile so I would hope it would find its way up the list quite soon), you may prefer to wait until that comes on line.
Even if you don’t want to use the app for control you can use it to load the profile (when available) and then run it as a standard sound decoder on your existing system. It’s a lot cheaper as well.

Many thanks Steve, further food for thought.

Am I right in saying that any stalling of a loco due to dead spots/dirty rails will result in sound stopping, requiring re activation? I would imagine this can be annoying.

If so, it’s either two speakers or, due to space, one speaker and a stay alive chip.

Correct. If the loco loses power either Dirty track or on points, it will stop then go through its startup routine all over again.
Until I started testing HM7K I thought that was something you just has to put up with. I tried the HM7K powerbank and it totally transformed the performance of the loco.
I now fit one to every new decoder I buy and have retrofitted all my TTS locos with stay alives as well.
There is another advantage to be had from HM7K - each decoder is supplied with a speaker but more importantly a variety of different enclosures. That should allow you to select the best compromise to fit everything in and get the best sound.