The Attack and Release Time Constant CVs determine how quickly the DDE reacts to a change in load or throttle. The Attack CV sets how fast the effect turns on when the load or throttle is increased while the Release CV set how fast the effect turns off when the load/throttle is decreased.
Each CV may be set between 1 and 255 with higher values producing faster response times. Generally, you will want to set CV 179 and 180 to the same value. Be careful not to set these CVs too high as it will allow the DDE to react to even minor changes in load such as occurs when traversing a turnout or slight change in track radius. This can result in rapid or erratic changes of the chuff volume and is quickly solved by lowering the attack and release CV settings.
CV 181, DDE Exhaust Low Volume Limit CV 182, DDE Exhaust High Volume Limit CV 183, DDE Side Rod Clank Low Volume Limit CV 184, DDE Side Rod Clank High Volume Limit
These four CVs determine how much the exhaust and side rod clank sound volumes will be boosted or cut in response to the motor load and throttle.
Each CV may be set anywhere between 0 and 255. A setting of 0 results in no change to the volume level while a setting of 255 corresponds to roughly a 12dB or 4X increase or decrease in volume level.
It is important to remember that these CVs do not set the actual volume level but rather control the percentage of change. The baseline volume level of exhaust or rod sound effects must still be set with the audio mixer level CVs (CV 131 for exhaust chuff and CV 134 for the rod clank).
Be careful not to set the baseline volume level too high or too low as the DDE cannot increase or decrease the volume beyond its maximum or minimum settings of 0 and 255 regardless of how high you set CV 181 thru 184. In other words, even though the DDE can increase the exhaust volume by up to 4 times (400% or +12dB), if the mixer level is set to 255, no further increase will occur. Similarly, if the mixer is set to 128, then the maximum volume change possible with the DDE is 255/128 or about 199% (+6dB).
CV 185, DDE Baseline Frequency CV 186, DDE Control Gain CV 187, DDE Filter Damping
These CVs influence the DDE’s ability to modify the exhaust chuff pitch and timbre.
CV 185 sets the baseline or ‘no load’ timbre of the exhaust chuff and can be set between 1 and 255. Lower values will give the exhaust chuff a ‘boomier’ sound but only to the extent that your speaker can handle the increased bass levels.
CV 186 determines how much the exhaust chuff pitch/timbre will vary in
Tsunami Steam Sound User’s Guide