Disclaimer: I don't own any locos with Paragon 3 decoders. I DO use an NCE Powercab for my layout, and to program all my locos with Soundtraxx Tsunami decoders.
First, a quick look at the online manual for Paragon 3 steam decoders (p9 and p15) suggests that a quick "double click" of the F8 button on your NCE controller will drop the sound one "level." There are 8 levels... when you reach the bottom level, additional double clicks of F8 with increase the volume one level at a time. It sounds as if these changes are transient, and are lost when you turn everything off.
To make a "permanent change" (one that will be maintained from one session to the next; but it can always be changed again), you need to re-program (change) the CV that controls the "Master volume." To do this on the Power cab:
- Select the loco you wish to program (it's likely you already have that loco selected, if you have been controlling it with the power cab). Many locos come with the default address set to 3, others come with the address set to the number on the model).
-Push the "Prog/Esc" button (lower left on your Powercab controller)...
-Push "Enter" to accept program on main...
-Push "Enter" to confirm the loco number...
-Push "2" to choose CVs...
-Push 1 3 3 followed by enter to select CV 133, which controls the master volume...
-Enter a new value... BLMI suggests a number less than 128 (which implies that 128 is the default value). I would suggest trying 64. To do this, key in 6 4 followed by "Enter"...
-When you are finished, press "Esc/Prog" to exit programming mode.
Test your volume... and adjust up or down to your preference by repeating the procedure above...
Page 9 & 10 of the Paragon manual provide a list of the volume CVs for many of the sounds... by changing them individually, you can "fine tune" their relative volumes to your own preferences.
Good luck...
