I agree with Zerogee, the black box is getting a bit old now and I am uncertain if you can actually access all the sounds through a driving decoder. The XLS will give the correct sounds actually digitally recorded from the original loco. Just as easy to fit as the driving only decoder except there is a speaker to mount and plug in to the decoder.
Actually - are there many different sound functions on the black box units?
Thanks for the info all, so if I decide on the Xls, how do I get as many sounds as possible to work on analogue using reed switches? And do I require a power buffer to keep the sound ticking over and shutting down on analogue?
I am not at all sure a power buffer can be used in the usual sense on analogue. The loco will keep moving when the controller is turned off. It is suggested analogue running is turned off in the decoder when a buffer is fitted. Whether a buffer can be fitted to just the sound bit I don't know!
Hm sounds to me like there is an expectation of a pretty tricky thing to do without going DCC. Personally I think you may be better sticking with what you have till such time as you make that switch, if you ever do.
JonD
Me to, do it.Ha ha - I'll bet you go digital.