Chuff - New Paradigm

[Joe Satnik]

Dear All, 

Boarders in a previous threads seem to be struggling to achieve satisfactory sounding chuffs at all speeds and loads.  Recently, it was theorized that faster triggers were interpreted by sound modules as "noise", and  thus ignored.   

Perhaps we need a new approach.  Up to now, we seem to have one trigger for both cylinders. 

Why not two triggers and two voices, one for each cylinder?  The "stereo" signals could then be mixed down to a mono output to the speaker. 

Think about it.  This would cut the chuff trigger rate in half, allowing for longer "decay" of the hissing sound for each cylinder.

Perhaps overkill: Have 4 triggers, one for each stroke (forward/backward) X 2 cylinders. 

Is there a difference between the sound of a cylinder's forward stroke and its backward stroke?  Is there a significant sound difference between cylinder action/chuff from the left side of the engine vs. the right side of  the engine if you are standing on one side?       

The live steam people are probably chuckling over our struggles to achieve "live steam sound"...

Sincerely,

Joe Satnik

[Greg Elmassian]

An interesting idea Joe.

One problem with current designs is that the "chuff" is a sound "bite" that is just played when it is triggered.

A good sounding chuff at slow speeds is "too long" at high speeds, and they run together.

What is needed is a sound system that can vary the duration of the chuff sound with speed.

One manufacturer has this in beta test right now, so hang in there.

Regards, Greg

[Tony Walsham]

Joe.
The K-27 already has four chuffs per revolution.
By removing a link on the socket pcb that can be reduced to 2 chuffs per revolution.

The RCS/EVO PnP-3 controller has solved the problem of poor chuff output by filtering the original signal from the cylinders and then inverting the signal to be compatible with most sound systems.
This filtering and inversion are built in.  There is nothing else to add to the loco.

My experience to date has been the K-27 works just fine on 14.4 volts.  This provides a quite reasonable top speed.
I do know for a fact that if you use greater than 14.4 volts to power the loco and then run the loco much faster than the speed it can achieve on 14.4 volts, the chuffs will blend into one another and lose definition.