If you changed the TT with another & it sounds good on
the Zenith amp its probably the cartridge. IIRC these had EV carts.
Look at the needle & be sure the needle is resting on a rubber thing
that goes to the cart. They break & fall off often.
This shows a magnetic but the layout is basically the same.
https://www.google.com/search?q=need...id:h5t4t5lzzA4
s
The part to look at is the "suspension".
73 Zeno
LFOD !