By popular request (really, I got quite a few emails about this!...;-), I finally completed my Beogram DC motor restoration video! It demon...
Sunday, January 29, 2017
Beogram 4000: Replacement of Corroded DIN5 Plug and Installation of a Grounding Switch
After rebuilding the control cluster the next step of my current Beogram 4000 restoration was to replace the original corroded DIN 5 plug with a modern gold plated all-metal plug, and to install a switch that allows connecting system and signal grounds in case there is a ground loop causing a hum in connection with the amplifier. This shows the rusty original plug:
And here the replacement:
Pretty! On to the grounding switch. This shows the terminals where the DIN cable is connected to the internal cartridge wiring:
This is the perfect spot to install the switch:
This switch allows to toggle between the B&O-original setup, where signal and system grounds are kept separate, and a configuration where both grounds are connected. B&O actually adopted this configuration in later 4002 and the 4004 Beograms. My experience is that if there is a hum, this connection in most cases suppresses it.