PIKO SUSI sound module buffer

[Neil Robinson]

I'm working on my first installation of a PIKO sound module. A mate has obtained a few at a good price and the first is for one of his PIKO 218s.

I've fitted a Massoth XL decoder to provide a SUSI interface, he runs both digital and analogue depending on various factors so a decoder was needed anyway.

I note from Massoth's instructions that analogue running has to be disabled if a power buffer is fitted to their decoder, so I won't fit one in order to permit analogue operation.

Now to the point, PIKO suggest wiring a storage capacitor to their sound module "for interruption-free enjoyment of the sound". I'd like confirmation that this is still a good idea when operating on analogue layouts.

Anyone know either the answer or a reliable source that would

 

[stockers]

Interesting question. i too would like to know the answer. A power buffer obviously has benefits such as keeping going when running over dodgy pointwork and dirty track as well as keeping the sound going.The analogue problem is what has stopped me going that route - although I run digital home, I do like going visiting.

 

[PhilP]

I believe the SUSI bus can power small items??

Possibly power would be fed-back the 'wrong way' and the current draw would nuke the sound module ??

No experience of SUSI, except it not working between Massoth decoders and pulsed smokers..

 

[Cliff George]

Well I think the first thing to work out is if the sound works at all in analogue mode.

It would depend on the decoder sending suitable 'speed' messages down the SUSI bus. I know my Lenz decoders don't do this in analogue mode (which doesn't bother me since I hardly ever run them on analogue).

I never bother putting power buffers on the SUSI sound modules, but I do use then on decoders.

 

[Gizzy]

My understanding of SUSI is that it is a data and not a 'power' bus as such. There are 2 wires for data and 2 wires to provide a low voltage to a connected device or module, similar to a PC USB connection. I would have thought the modules would have protection for 'wrong way' power Phil?

I have a LGB 21900 KoF DUO which is fitted with a Massoth M decoder and a small S decoder. I was given a SUSI cable to link the 2 decoders but I couldn't get it to work so removed it. The loco is also fitted with a Massoth Power Buffer to keep it running on dead frogs/dirty track, rather than to the sound module.

So to answer Neil's question, if you are wiring the buffer just to the sound module (and therefore not the motor decoder), it would just keep the sound going, when analogue power is off. I know Neil has previously fitted a power cap to LGB 6500X sound modules for this reason, so I should think it is a similar scenario....

 

[Neil Robinson]

No experience of SUSI, except it not working between Massoth decoders and pulsed smokers..

You probably know this but just in case there are two settings for the SUSI connection on the Massoth decoder that I'm currently working on. One is a "Massoth bus" for things like their smoke units and the other "SUSI bus", unsurprisingly for SUSI devices. It's changed by bit 4 of CV 49

 

[Neil Robinson]

Well I think the first thing to work out is if the sound works at all in analogue mode.

Thanks, I found this post very helpful as it doesn't work on initial analogue testing. I don't have digital kit (other than a programmer) at home but I'll wait and see if it works on digital before attempting to find out if I've done anything wrong.

I'm confident that the Massoth decoder installation's O.K. as the motors and directional lighting work as expected on analogue.

I've just had a look at PIKO's website and some, including the 218, state that they are only for digital whereas some others with different sounds don't say anything about digital only.

 

[PhilP]

You probably know this but just in case there are two settings for the SUSI connection on the Massoth decoder that I'm currently working on. One is a "Massoth bus" for things like their smoke units and the other "SUSI bus", unsurprisingly for SUSI devices. It's changed by bit 4 of CV 49

Thanks Neil, yes..
Didn't work any which way.. Ended up fitting a 'cam axle', which worked perfectly. - Once I got the two wheels EXACTLY 90 degrees quartered! :

 

[Zerogee]

I was always under the impression that all SUSI devices worked on DCC only, not on analogue?

I have one of the Dietz T3 railbuses with one of their own SUSI sound chips installed, the motor will run on DC but the sound doesn't.

Jon.