Sonab 75 S hum

Hello !
A few months ago I bought some 20+ years old (Swedish) Sonab 75 S 'hi-fi' turntable. The deck looks lovely and... worked perfectly until suddenly 'something' went wrong and now, together with the music, I also hear the constant electrostatic hum :( I mean when I put the power on the hum is already 'on'... then it disappears, but only when the arm is going (automatically) down / up... when it's on the record the hum is again 'on' :( I changed the cable connecting the turntable with the amplifier... I took the headshell with the cartridge off... the hum is still present... what (the hell) is wrong ? It was perfectly OK when I bought the turntable... I do hope you'll be able to suggest any solution, please ! Thank you very much in advance...




2007-12-15 6:29 pm
You have probably found the solution by now but I have only just spotted your post.

I found that after removing the original DIN plug and replacing it with phono plugs that I too had a quite bad mains hum on it.
It turned out to be poor earthing - I found it necessary to earth to the chassis of my amp (a Quad 405) after which it was fine.