Chuff rate adjustment on Massoth XLS

[stockers]

Need some advice please.
I have fitted a Massoth XLS with Mallet sound to my LGB Mallet. The chuff speed is way too slow, I am getting one chuff per 1 and a quarter full rotation of the wheels (no sensors here- just voltage).
Question one - How often does a compound exhaust - being compond I assume it only exhausts from the low pressure cylinders, therefore 4 times a revolution.
Question two - How do I adjust this. It looks like CV 198 (spacing between steam chuffs). Default setting is 1, do I set this to 4 ?
Any ideas

 

[Neil Robinson]

Need some advice please.
I have fitted a Massoth XLS with Mallet sound to my LGB Mallet. The chuff speed is way too slow, I am getting one chuff per 1 and a quarter full rotation of the wheels (no sensors here- just voltage).
Question one - How often does a compound exhaust - being compond I assume it only exhausts from the low pressure cylinders, therefore 4 times a revolution.
Question two - How do I adjust this. It looks like CV 198 (spacing between steam chuffs). Default setting is 1, do I set this to 4 ?
Any ideas

I'm a real beginner with Digital, but I'm trying to get my head round sound decoders in order to fit quality sound units to analogue locos by using analogue compatible sound decoders.

Question 1, your assumption on four chuffs seems fine for the LGB compound Mallett, but I suspect the exhaust of these prototypes may sound fairly muffled.
I don't think synchronising the exhaust to the wheel revolutions matters that much, as I've read in some sound instructions that it's acceptable set triggers to only chuff twice per revolution rather than four times as some people prefer to hear the separate chuffs at relatively high speeds. So providing the chuffs start as the loco starts to move and the chuff rate sounds O.K. for you, that's the setting that's right for you.
I assume that the higher the CV values for both CV 196 and 198 the longer the duration of chuff and delay. If so the default values of 28 (max 32) and 1 (max 16) will give a long chuff and short pause between. I therefore suggest you experiment with these two, you can always reset to default. I suggest setting CV 196 to 20 and leaving CV 198 on 1 may give chuffs of shorter duration and the same spacing as before, i.e. sounding faster.

 

[muns]

Increasing the value of CV198 will just increase the gap between the chuffs. I think that I would go down the route Niel has suggested, that is decrease the length of the chuff by reducing the value of CV 196.

 

[Philbahn]

My Rugens settings Are; 198 -2 196-9 Works for me

 

[stockers]

Thanks for the ideas guys. Changed 196 to 18 and I am getting about two chuffs per revolution. Not prototypical, should be 4, but is sounds about right for the speeds I like to run at.

 

[stevelewis]

It is very much a trial & error job as stated above, I have spent many a happy hour or so !!! Trying to get Mallets and Saxon Meyers to sound correct, and no doubt will have to do it all agian when the new Mallet arrives!!

 

[stockers]

It is very much a trial & error job

Too true Steve. I just lowered CV196 to 12 and it's much better. Difficult to count the chuffs per revolution (about 2 and a half maybe!) but it sounds right - Brill.

 

[Philbahn]

Alan Just lowered 196 to 4 on my mallet sounds even better