Just received a very good looking Beomaster 900K which is in good working order and makes a very good sound for 2x6w. Very pleased! It’s my first B&O, having spent most of the 1970’s looking at friends’ parents 2400’s and up systems. Question - At power on, its quiet with no aux connected. If I plug in a 5 pin din to 3.5 mm lead, within 10 seconds a buzzing starts and gets louder until something (unearthed and not on mains power) is connected when the buzzing vanishes thankfully. Does this need fixing or just ignore? What is building up here? FM is amazingly good even with what I presume is an internal aerial plugged in via 3 pin plug to the FM/UKW socket. Sound is so warm. Whats an easy aerial for the rest to plug into the other socket? I don’t have the plug though. Otherwise all seems to be in very good order and lights and dials all working. Are there any maintenance items to do/clean/ other? I’m not going to start soldering just yet! many thanks