hum on preamp phono output

[ger56]

hello

I have hum on my phono preamp output .

When connecting my turntable , hum is quit big and reduce 90% when connecting aplifier earth .

I try to make a direct wire from cartridge to phono output , same problem , i change the cartridge , same problem , so I suspect the phono output but I do not know many in electronics .

When thre is no connection on the phono output thre is still hum .

My preamp is 20 years old with component like :

NE 5524 AN
B32520 u22K100
itt 25V 47 uf.

Can someone give me some help , should i chnage the itt caps 47 uf ?
alos if i can upgarde it , the phono is on a single card !

thank's