Am just about ready to get into sound. Just a few questions, Since all my locos are DCC equipped are there any good "sound only" decoders? How many sound equipped locos can you run at one time until it gets distracting? Do you have to have sound in both the A & B unit of a lash-up to sound right? Thanks....Jerry
I find it's best to remove the original decoder, and plug in a "Motor/Sound" decoder, such as Soundtraxx Tsunamis which have sounds tailored to the prime mover of your locomotive.
Soundtraxx now has sound boards to replace the original decoder boards found in Bachmann diesel locomotives.
To answer your last two questions: It's a matter of personal preference, no rigid rules.
You should do some research first at:
http://www.soundtraxx.com/
Regards