The 1970's B&O are generally rare to see in white. I believe they were considered "cheaper" looking
than the "elegant" wooden finishes and most white versions were actually slightly cheaper.
Today, the white models are sought after, not only by collectors, and many people regard them as
being more timeless design pieces.
All CX50 will develop foam rot and if yours still have the original woofers, they will fall apart when
you touch them. Even NOS (New Old Stock) woofers will have foam rot, even if never used.
If yours are OK, I'm sure they are replacements - which is of course fine.
The Beomaster 3000 and 3000-2 transformer is often humming. The transformer will do fine and
the Beomaster will play on nicely but the humming will grow annoying with time.
The transformer is cast in a metal case and - at least until someone comes up with a reproduction
transformer or some other fix, the only solution is to find a transformer from a donor Beomaster or
simply live with it. You can dampen the coupling to the furniture on which the Beomaster is placed slightly
by fitting a couple of foam blocks underneath the Beomaster but don't cover the ventilation holes
in the bottom plate.
Martin