I have just modded a BM2400-2 with LED's on all the RED lights (except for the 2 Volume lights).
Not a simple job, in fact a lot of research in redesigning the circuit, but the results are very good.
Actually the Phono, Tape and P1-5 lights were originally designed to work with LED's, according to the datasheet of the SAS570S driver. B&O made an (IMHO) unnecessarily complicated circuit to run them off incandescents. I have retained the signal going into the IL1 fault circuit.
The 3 Green lights cannot be converted to LED's without a major redesign, and even if I had the time and inclination to develop the mod, it would be beyond the scope of most of the readers here. And, my primary objective in designing these mods, is to make them friendly enough for any of the members who are reasonably proficient with a soldering iron, to be able to understand them, and install them with ease, and have fun doing it!
Anyway 5 incandescents are much easier to replace, than 15!
I'll be posting a full article once the restoration is completed, including full instructions on how to make these mods. This of course, applies to the BeoMaster 1900 as well.
Here's the Bass Treble Balance PCB.
Menahem
Learn from the mistakes of others - you'll not live long enough to make them all yourself!