A tip from Soundtraxx...

Both Tsunami and SoundTraxx Mobile Decoders have this feature. 

This bit in CVs 49-52 actually changes the way the lighting effect is sent so that it helps make the LEDs appear and behave as if they were incandescent bulbs.  

To see this in action, install a LED and a 1k (1000 ohm) resistor onto the white wire (F0f, Headlight) and the blue wire.  

The default value for CV49, Headlamp control is 15, but change this to 2 for a Mars light.  

The effect is there, but not very vibrant, as you’d expect.  Add in 128 (128+2=130) into CV49 and look at the mars light now.  

It has the expected pop!  This will help all of your customers’ or your installs behave and appear more realistic than many other decoders on the market! 

It is important to note that this does not change the output voltage to regulate for LEDs, so resistors are still required.