Phono stage hissing
My phono stage which until tonight has been fine, has suddenly started hissing loudly in a white noise sort of way. This is on the MM setting, if switched to MC it's hissing, but more bassy.
Is this the sound of death? I've tried it using different inputs on my amp, but it sounds the same. I've also disconnected the power supply from the turntable, but the amp still hisses. Other sources play fine.
The phono stage is a Rotel RQ970BX, turntable Rega P3-24, with Ortofon Red Cartridge.
Any suggestions welcome