Installing TXS decoder to Hornby Dublo A4

[Train Mad1707822774]

Hello.

I purchased one of the new hornby dublo Sir Nigel Gresley a4s. I've only opened it today now that the android app is out. I am about to fit one of the TXS decoders, I have fitted TTS decoders in the past but this is different in that it has a sugar cube speaker, apologies if this as been asked before but I've searched and not found any answers to my query. Looking at the speaker enclosures I think the largest one that will fit is the second smallest, I was wandering if anyone as fitted one of these and used a larger one. After looking online I was intending to fit the speaker to the tender chassis with the speaker pointing up stuck down with blu tack, this tender doesn't have the circular space for a speaker but does appear to have slots for the sound to escape. I am not sure just thought I'd check here first.

There is one other thing I'm sure I've read that there should be no other Locos on the track when installing a new sound profile, this doesn't make sense to me as all my other Locos are normal DCC, perhaps I've read it wrong or just my lack of understanding.

Thank you in advance for any help received.

[SteveM6]

I’m not familiar with the latest Dublo locos (yet) but the usual rule of thumb is to use the largest speaker enclosure that will fit. Trial and error will get you there on that one but don’t peel off the sticky bit on the speaker until you have finalised your selection. They cannot be unstuck without destroying them and spares are not yet available.

Black Tac is better than blutac as it is stickier by the way.

You don’t need to isolate locos on separate tracks when programming - HM7K ‘talks’ direct to the unique decoder address which I shall the exact opposite of standard DCC. However, other Locos on track can produce spikes or interference in the power supply, so that’s another variable that could upset the programming process. IMHO it’s best practice to have a programming track or take all other Locos off the layout.

For example, my setup uses an Elite to power the layout but I invested in the Hornby dedicated 15v supply specifically for the programming track. It’s a bit belt and braces but it works.

[Train Mad1707822774]

Thank you for your very quick reply which is most helpful. I don't think a bigger speaker will fit so I might have to settle for the one I mentioned. I do have some black tack but for the life of me I can't seem to find it, I can of course buy some more but I do have some double sided tape which I did consider using.

What you said about other Locos on the track causing interference whilst programming makes sense, I never gave that a thought. I have a Bachmann Midland Pullman which has been sitting on my small layout since I took it out of the box brand new about a year ago, I will take this opportunity to put it back in the box, I've been putting it off for ages it was such a chore to assemble it on the track when I first acquired it.

Thank you again for your advice, very helpful and is much appreciated.

[Train Mad1707822774]

 I've just had time to have another look and found that there is a space for a circular speaker, it doesn't help me but I just thought I'd correct my previous comment. Having done a bit of trial and error I don't think I can fit a larger speaker than the second smallest.

 Whilst I was looking for a good place to put the speaker without it affecting the very fine wires and pushing them down to a point where they would catch on the wheels I noticed that at least two pickups are not making contact with the wheels, I do hope the others are ok I can't see them properly but they look ok as far as I can see. I do have a power bank but was saving that for future use.

Thanks again

[Train Mad1707822774]

Just a little update I have fitted the decoder and speaker.

 Having done a lot of googling and watching you tube videos I realised that this particular model has got a different DCC socket which is larger than the usual socket as it incorporates a PCB. This prevents fitting one of the larger speakers so I made do with the second smallest.

 Much to my surprise it doesn't sound bad at all I just need to lower the volume as it's incredibly loud and the whistles distort.

 I found the app easy to use it took a little over half an hour to install the A4 sounds and probably another half hour finding out how to do it.

 I used my xiaomi Pad 5 and had no problems whatsoever, I do have a Samsung phone which I probably could have used but I prefer a bigger screen.

 I noticed the PCB I previously mentioned has a 2 pin socket which seems to be the same as the speaker socket on the decoder, there is no mention of this anywhere in the instructions that I've seen just wandered what it was.

 I am really pleased with this Loco it runs sweet as a nut and it's not even been run in yet.

 I haven't tried it on my DCC setup which uses an elink but I think it'll be ok.

Just having a coffee and a break now, I feel like celebrating, I didn't expect this to go so well.

Thanks again

[ColinB]

There was a thread on the extra 2 pin connector on the Hornby Dublo A4 Sir Nigel Gresley. As far as I know nobody ever responded to what it was for. As to speakers I use Road and Rails ones, they sell a very thin one that fits well and sounds really good. An HD loco is no different to a normal A4 made by Hornby, except the Railroad varieties (different tender and DCC fitting). The new HD Sir Nigel Gresley has a different drawbar with integrated pcb so I assume the tender bottom is different, I haven't taken mine apart yet to check. Because these tenders are long there is plenty of room for the decoder plus bass speaker, just avoid the front where the coal bunker slopes and the extreme back where the tender top dips.

[Train Mad1707822774]

The problem I found was that the Dcc socket PCB means you have to fit the decoder nearer to the front, and as you say the coal bunker gets in the way. Whilst looking on you tube there was one video where the chap was fitting a non sound decoder into a R3320 Golden Eagle, there was also another where a chap is fitting a TTS decoder into R3441 Sir Murrough Wilson in both cases the tender does have plenty of space it has a small DCC socket which means you can fit the speaker further back.

You are right when you say the tender bottom is different in that they have replaced the DCC socket, I don't know if there is any other difference.

I really like the new connection it's much better than the plug which can be a bit of a fiddle so I suppose this inconvenience is a small price to pay.

Thanks again all advice is welcome and appreciated.

[Train Mad1707822774]

I have been running the Loco in and since I turned the volume down there is no distortion at all I just wish it had a bit more bass. I've had a look at roads and rails They have quite a few speakers which look very thin and might fit. I think I would need an 8ohm speaker but not sure. I'm only thinking about it as it was very difficult getting the existing speaker to fit, the tender top was catching the top of the speaker.

I might live with it because it's not really too bad just lacks bass. Perhaps I've been spoiled I've quite a few sound locos which were sound fitted either at the factory or by one of the DCC sound specialist companies. I do have an A4 I think it's Sir Ronald Matthews that is DCC sound fitted by Hornby, I've never used it since I purchased it brand new from an ebay seller, I'm pretty sure it's an ESU decoder in it. I might dig it out and see how it compares to this before I decide what to do.

If anyone reading this has any experience fitting sound to this Loco please let me know how you got on. I would appreciate that very much.

Thanks again for any help or advice.

[Train Mad1707822774]

 I've ordered an iphone speaker and a bass enhanced speaker from roads and rails as was recommended. I think one of them the should fit if the other doesn't. It's a pity you can't seem to get the plugs for the speaker not that I've found anyway.

 I also got a few other things that I needed and it cost me less than £20, very good value I think. Thanks for the recommendation.

[Brew Man]

I just cut or desolder the lead with the plug from the duff or unwanted speaker and solder it to the new one.

[Train Mad1707822774]

That's my plan but it would be handy if you could get spare plugs.

Thanks for the advice it's much appreciated

[96RAF]

Try searching for these but although you can buy the plugs and terminal pins they are tiny and very, very difficult to assemble.

[ColinB]

To be honest these JST connectors are too small to deal with. I do as someone else mentioned earlier just cut the speaker supplied away from the lead and solder the new speaker to the old lead. Those JST connector quite often fall apart when put together properly by the manufacturer so unless you are very good at assembling them, assembling them yourself is best avoided.

[96RAF]

To be honest these JST connectors are too small to deal with. I do as someone else mentioned earlier just cut the speaker supplied away from the lead and solder the new speaker to the old lead. Those JST connector quite often fall apart when put together properly by the manufacturer so unless you are very good at assembling them, assembling them yourself is best avoided.

 

 

Totally agree Colin. I have trouble with wiring the pins for full size Molex connectors so working these toddlers is a non-starter for me.

[Brew Man]

Yes, even if they could be found, they'd have to come with the wires attached for me.

[Train Mad1707822774]

Thank you for this I will look for them. I wonder if you can get them with wires attached, I've had a google for jst suhr-02v-s-b and spotted something that came up on farnell but I don't think it's a plug it says receptacle to receptacle and it's a different part number 02XSR02XSR36L50, it does look similar though. I might order one anyway they are very

cheap.

Thank you so much at least now I know what to look for.

This advice is very much appreciated. Thank you

[Brew Man]

I found some very small JSTs that looked about the right size but the ones on the decoders have a slight bevel to them which the ones I saw didn't appear to have.

[Brew Man]

I think these are they:

https://www.ebay.co.uk/itm/223630461716?_trkparms=amclksrc%3DITM%26aid%3D777008%26algo%3DPERSONAL.TOPIC%26ao%3D1%26asc%3D20221020120438%26meid%3Db7e492b8c4bb4235982322660f7558e3%26pid%3D101574%26rk%3D1%26rkt%3D1%26itm%3D223630461716%26pmt%3D0%26noa%3D1%26pg%3D4375194%26algv%3DPersonalizedTopicsV2WithV7Unbiased%26brand%3DUnbranded&_trksid=p4375194.c101574.m47269&_trkparms=parentrq%3A01821a6a1890ab9739b8af6effff723e%7Cpageci%3Afdba71cc-159c-11ee-a878-56e8b1d491e9%7Ciid%3A2%7Cvlpname%3Avlp_homepage

EDIT: On second thoughts, I don't think they have the bevel either.

[ColinB]

If you don't want to get them from China via EBay, I think Road and Rails does them with leads attached.

[Brew Man]

Again, they appear to be the square type, not the ones with the slight bevel.

[96RAF]

If you look at the image I posted you will see the pitch is 0.8mm not 1mm as per the eBay listing.

[96RAF]

Ref only is this data sheet - look at top line in the table on page 2. Then you can see the PN decode in full on page 3. Crimp pins are on page 1.

https://www.jst-mfg.com/product/pdf/eng/eSUH.pdf

[WilliamDavid]

On most of my tender fitted locos I have removed the weight from the tender, which allowed me to fit a larger speaker and the stay alive.

I put some lead under the coal load, although I am not sure this is necessary.

[Brew Man]

But once again those plugs appear to have a square profile. The ones on our decoders are slightly trapezoidal.

[96RAF]

But once again those plugs appear to have a square profile. The ones on our decoders are slightly trapezoidal.

 

 

I can only pass on info from the official Hornby drawing.