Sound chip for DP2?

[Monday]

I have a Heljan DP2 which runs beautifully on DCC with a Hornby 21 pin Sapphire(?) chip. I tried it with a Hornby TTS Class 50 sound chip (the prototype has a Class 50 power train) but it didn’t work - at all. It was subsequently replaced under guarantee and fitted to a Hornby Class 50 and has worked fine ever since.
I have since read that Heljan motors may draw more current than the TS chips can handle - so I may have burned out the chip? I am therefore reluctant to fit another TTS chip, even if I could get one (they are out of stock everywhere). I am going to have to bite the bullet and fit a ‘proper’ chip to this loco. Any ideas as to the most economical option?

[Bigmet]

If the sound from the TTS class 50 decoder is good for you, then one option is to install a silent decoder to run the motor and lights, and the TTS decoder solely to run the speaker. Not problematic in a large diesel model's body shell.

[Monday]

Thanks for that - something I hadn’t thought of. Not problematic in spatial terms but electronically? Presumably the tts chip would have to be wired to some of the output from the Sapphire chip?

[Bigmet]

No, wire each decoder to the track supply (red and black) each will receive the commands independently and do their own thing. The motor decoder would best plug into the socket, the sound decoder can be wired to red and black wherever convenient, Heljan locos typically have terminals on the board ends for the track power, which are a good location.

There may be some fiddling required to match movement to sounds, and one way to do this is to programme them on two different addresses in two different locos, then changing to one address and testing before installing in the DP2 once satisfied. (It may be possible to do all the adjustments in the DP2 with both decoders on the same address, if there is no conflict between the CV's that have to be adjusted - not knowing these decoders I cannot advise.

[Monday]

Hmmmmmm, thanks for that but I can see a few issues there for someone with two left feet like me! Plus the fact that I cannot get hold of another Class 50 tts decoder for love nor money. In googling, I came across a Howes 21 pin decoder specifically for the DP2. Expensive so not something I will do immediately.
You sounded slightly disparaging about the tts decoders but they suit me when I can find appropriate ones - they’re cheap but limited range though. But I don’t need station announcements and door slamming!
Thanks for your help.

[centenary]

TTS chips are good, cheap and very hard to get hold of once sold out. Howes and a few places do sound decoders for the DP2 but generally, these are like Loksound so are more expensive.

[Bigmet]

...You sounded slightly disparaging about the tts decoders ...

It's a 'made down to a price' product, and one limitation as a result is very limited power output, just 0.5 amp total. This really is a little low, as sound production is current hungry, and in combination with the traction motor the decoder is easily overloaded. Most silent HO/OO decoders are rated from about 0.8A total or greater.

You have noticed the lack of supply of the class 50 TTS decoder, there's been quite a lot of recent comment about lack of TTS decoders generally. This may be partly to do with the well known shortages in electronics manufacturing in China, but there's possibly another factor that I have not seen much comment on yet. Hornby's 2022 range has promotion of 'steam effects' by water vaporisation, and it may be that their decoder production has shifted to give this priority. Wait and see on this...

[boxbrownie]

I put a Zimo Deltic decoder in my DP2……..I just thought a deltic (shape) Loco without the VVV12 engine noise isn’t right

[centenary]

I understand the engine for the 50 was based on that used in the DP2.

DP2 was not 'Deltic Prototype 2' as many think. It was just Development Prototype 2. Unfortunately the model shop who sold my wife a DP2 told her it was (a Deltic) which was why she bought it for me. Havent the heart to tell her it isnt a Deltic.

[boxbrownie]

I understand the engine for the 50 was based on that used in the DP2.

DP2 was not 'Deltic Prototype 2' as many think. It was just Development Prototype 2. Unfortunately the model shop who sold my wife a DP2 told her it was (a Deltic) which was why she bought it for me. Havent the heart to tell her it isnt a Deltic.

Absolutely correct, the DP2 had nothing like a ‘deltic” engine it had a forunner to the Class 50 engine, but I had a spare deltic decoder in the box