16 or 8 ohm speaker ?

[Hartley118]

I'm guessing that the expired cartridge that you replaced was a crystal type. It may be that the replacement has a lower capacitance than the original and so may need a higher load impedance. A crystal or ceramic cartridge effectively incorporates its own rather low value coupling capacitor, typically of the order of 2nF and usually needs a load of at least 1Mohm to preserve its low frequency response

Achieving a high input impedance in transistor amplifiers of that vintage was always a challenge. If you've got plenty of gain, the first thing I'd try in order to get more bass response is to connect a 470k resistor (or more) in series with the input to present a higher load impedance to the cartridge.

Martin