Bachmann Class 37 fitted with TTS issues

[Chrissaf]

Moderator message: This post was originally posted by "dwright" as a hijack of another's thread. It has been reproduced below as a new original thread.

I am trying to get my Bachman class 37 loco (with 8 pin DCC connection ) to function with a Hornby TTS decoder.

When fitted the loco moves backwards and forwards (although not in the direction I expected) the lights come on and off with F1 but there is no sound what so ever.

What am I doing wrong?

[Chrissaf]

According to the Class 37 TTS decoder data-sheet. F0 turns on and off the directional lighting and F1 turns on and off the 'Engine Running' sound. So what controller are you using.

Is the 8 pin TTS decoder plug placed the right way round in the socket?

If the plug is reversed 180° then the loco direction being reversed is a typical observation that a plug reversal creates, coupled with the directional lights not working. But 'sounds' would not normally be affected by a plug reversal. Assuming that they have indeed been switched on with F1.

[dwright]

I have tried the plug in both ways round and the loco reverts to the expected direction with the plug in the wrong way round but still no sounds.

You are correct in that it is F0 that turns the lights on and off but none of the other sounds work.

The controller that I am using is a Zimo MX 10 and a MX33

[ColinB]

It may be that you have the same issue I had with one of these decoders, the sound didn't work. I returned it to get a new one. I learnt very early on with these decoders and advice from members of this forum, to buy a decoder tester. With TTS decoders there is a minority that have issues, so I always test them before I fit them on a loco tester. It becomes really important with the 21 pin Bachmanns as the only way to get then to fit it to hard wire them to a 21 pin header (not enough headroom for an adapter), so before you cut the 8 pin header off you really need to be sure the TTS decoder works.

[Chrissaf]

TTS decoders have a very high failure rate with regard the sound aspect of the decoder. The faults include the speaker being completely dead and 'open circuit' [do you get any resistance measured across the speaker using a multimeter?].

Sound playing but being very low volume or distorted.

No sound because the amplifier output stage of the decoder has been damaged.

There is no easy way to test for the decoder amplifier fault, but the speaker can be tested by connecting it across a suitable sound source such as the speaker output of some other low volume audio device, a portable radio for example [temporary test lead with suitable jack plug connected to the headphone socket for example].

If the speaker is OK, and the F1 function command is not starting any sounds, then suspect that the TTS decoder is faulty and return if for replacement / refund under Warranty.

[dwright]

Gentlemen

Thank you very much for your advice - it is much appreciated.

I will check the speaker and decide if the decoder needs to be sent back.

As I purchased it from Amazon should it go back to them or straight to Hornby?

[ColinB]

I sent the class 37 one back about 3 weeks ago. I plugged it in the tester it buzzed for about a second then no more. As a decoder it worked perfectly. I tested the speaker which was 8 ohms and replaced it with another, but still no joy. Fortunately I now have one that works. It is worrying though, that they are so unreliable, I had one one Saturday in a Battle of Britain that just suddenly lost sound after 10 minutes, fortunately after switching the DCC off and then on the sound returned. I suppose with the expensive Zimos and Loksound devices, they have to test them to load the sounds so generally they get tested before you buy them.

[Chrissaf]

In the first instance brand new faulty purchases should always be returned to the selling retailer. Amazon in this case.

[dwright]

I currently have three Zimo sound decoders in various locos which cost an arm and a leg but they work and work well.

This is my first attempt with a Hornby tts decoder and it was purchased as an experiment to see if a decoder which is approximately 1/3 of the price of the Zimo was a reasonable investment.

The answer would appear to be no.

[ColinB]

I have loads of TTS decoders at least 20. I also have a few Zimo and LokSound decoders. As long as you accept that the TTS decoder is what it is and as you say it is a third of the price then there really is no issue. The TTS decoders are guaranteed for a year even if you damage it accidentally, so they are worth the money. I have been a critic of them but I now accept generally that they are good value. Yes, I get the odd one that doesn't work but generally they work ok. Virtually all my Bachmann diesels are fitted with them and they work ok, I do have two with LokSound decoders in that came with the locos, they do sound better but are significantly more expensive. So don't let this put you off put a good speaker on the diesel ones and they are perfect and generally once fitted, work ok.

[morairamike]

I have three TTS decoders, 2 fitted to A4s and one fitted to a Castle all Hornby products.

Problem I had was with one of the speakers failing, Hornby replaced the speaker. But I changed all the speakers for sugar cubes. No problems since. My layout is DCC (yes I know to get full sounds you need DCC), controlled by Prodigy Advance 2 and snubbers fitted to the two halves of the layout.