Little Singer HE2200 battery 33/45
 

Found this at Kutztown today. NIB and clean. Powers up, spins at speed but the audio is kerflempt. I can hear the record but the hiss above it is drowning it out. Pure hiss that increases with volume. Can't find a schematic online. Should I be looking at the cartridge or beyond in the board and it's 50 year old components? I have not opened it yet awaiting your wisdom.

Got an audio generator? Unhook a lead from the cart and feed the amp audio directly. If it don't sound right coming out of the amp or requires more signal than the cart was meant to make to be audible than look at the amp first. If the amp works well look at the cartridge.

The cartridge may be bad; but, for the hissing problem, I'd be looking for a noisy (likely germanium) transistor.

Yes, I suspect noisy germanium transistor also.