O gauge TTS - doubling up decoders

[Jinty3f]

With the promised advent of the Hornby TTS sound decoder for the 4mm 08, I have started to wonder whether it would be feasible to bypass the power output element in some way, in order to utilise the sound facilities only, whilst retaining the higher amperage  non sound decoder currently powering my Dapol O gauge 08? I do not underestimate the problems that may arise - which decoder would take precedence, would they oppose each other, different number of pins, linking the sounds to the status of the beefier decoder etc. I just wonder if anyone more knowledgeable has already tried this with some of the existing TTS decoders in 7mm locos. I understand that some members do not rate the performance of these decoders in relation to speed etc, but I think it might be an interesting challenge, although outside my own technical expertise. Any comments would be gratefully received.

John

Edited February 5, 2019 by Jinty3f
Edited to add tags

[Vecchio]

The Dapol 08 draws far less than 0.8A so I do not see a problem with it in using the Hornby TTS decoder.  As long as you do not constantly pull 20 handmade (heavy) wagons with it... 

Question would be the connection? The TTS comes with NEM 652 if I am right and the 08 comes with a 21 pin socket...

[Izzy]

I have done just this with a Bachmann 4mm diesel loco which the TTS motor control just could not drive satisfactorily whatever settings I tried with it, and believe me I went through them all via my Sprog & Decoder Pro.

 

So I did as you propose and used the original decoder, a Zimo MX600, to power the loco, with the TTS  ‘piggybacked’ to provide the sound. All it needs is for the TTS track feeds to be connected and a speaker, and for it to have the same address. It does not need to be hooked up to a motor. In respect to playing the sound it does of course help if you can adjust the TTS acc/dec to match the loco’s motor control. 

 

I believe the Dapol 08 has a 21pin socket, But I don’t think you need to touch this at all, or the fitted 21pin decoder. Just find the track feed and add the TTS track feed wires where they attach to the pcb board fitted. Well, that is what I would do anyway. Apart from that it can be an entirely separate fitting.

 

I do also believe that the TTS limit is 0.5amp, including function output, so it could be the safest option.

 

Izzy

[Vecchio]

TTS 0.8A

regards

Vecchio

[Vecchio]

By the way - a zimo MX644 with the sound file from youchoose with immersive drive is worth the money. Then the loco drives like it should - you just have to learn that you have to break to stop it.  And you just plug the decoder in. Same with the speaker if you have the right connector. Job done. 

Have it on a Dapol Pannier tank - sound unbeatable. 

[Izzy]

If you wanted to try the TTS on it’s own then there are 8pin-to-21pin adapter boards. How this might affect the lighting functions I wouldn’t know. The same would apply if you just added the TTS as per my previous post, what function conflicts there might be.

 

Izzy

[Johnfromoz]

A forum member reported here on using the Hornby 08 TTS chip in the Dapol 08 a couple of months ago. Sound was all good but not full lighting functions ( no real surprise there).

 

I too intend on using the TTS chip for my Dapol 08s when the chips are available. The 08 file is one of Hornby's better efforts. I have Digitrains 08 file on a Zimo already, just would like a contrast as no two gronks sounded the same.

[RAF96]

Whether you can address a TTS decoder without a motor load normally depends upon your controller. Some will, some won’t. If you are addressing both power decoder and TTS decoder together then its no different to doing simultaneous power and dummy car addressing.

 

Be aware if changing CVs 3&4 on either or both deocders then TTS steamers need these to be minimum of value 15 to make the cylinder cock release time sequence correct before the loco moves off and diesels need it for brake release before move.

 

Edit -  21-pin can be full authority or logic only for some outputs. You would have to check the spec to see which unless a knowledgable person here can advise which is which.

 

Rob

Edited February 5, 2019 by RAFHAAA96

[meatloaf]

My Dapol 08 runs great with a TTS decoder removed from a Hornby DB shenker 08. Plenty of room for a bigger speaker. Only issue is the lighting, you only get the top marker light working in direction of travel

[Johnfromoz]

As per meatloaf’s experience,  I have used TTS in about four Dapol 08s from the first batch, with upgraded speakers they run and sound brilliant.  As said, the shunting lights were inoperable but top lights worked.

 

i have now ordered one of the modernised 08s from the new batch (with the lower level lights only) and am pondering whether TTS will now operate these.  In fact, can anyone recommend a decoder, sound or otherwise, that will control the shunting lights on this new batch?
 

Thanks

[RAF96]

On 08/02/2019 at 00:10, meatloaf said:

My Dapol 08 runs great with a TTS decoder removed from a Hornby DB shenker 08. Plenty of room for a bigger speaker. Only issue is the lighting, you only get the top marker light working in direction of travel

 

You could hang the other lights on F25, green wire.