I need to determine appropriate stylus replacement for the Sony PS-LX300USB Turntable

You have either knocked the connections to the cartridge causing a loose connection, or not seated the stylus right. Or you have static build up, which can be caused by poor earthing.

Perhaps you need to adjust the weight of the cartridge on the recording.

I just received the Sony PS-LX300USB turntable but cannot play sound through the computer speakers. States to setup Playback USB Audio
CODEC which shows working and Recording it shows Microphone USB Audio CODEC which is working. How do I get sound???

hi,
Select the switch to line. Then connect the red and white RCA pins to the corresponding red and white sockets of MD/CD-R play input of Yamaha. Select the MD/CD-R by pressing the button on the remote. Then play the turntable.
OK

Depending on the cartridge design the stylus is part of an assembly that typically just slides out. It will look like this if you have the original one...

http://www.lptunes.com/Elliptical-stylus-for-Sony-PS-LX300USBE-turntable-p/stpslx0300usbe.htm

The whole thing just presses in and friction is all that holds it in place. The actual stylus ("highly polished special elliptical diamond") is that little tiny point on the skinny metal piece ("thin wall aluminum alloy cantilever"). THAT part is NOT a subassembly for you to take off.

The stylus is the needle! If it doesn't have a sharp point on it it's either broke or missing.

Hold the stylus at an angle, rear up/needle down. Put the rear of the stylus in first and then push the front of the stylus up and clip into place.

Which stylus number did you use?
D.

It generally goes on the cartridge fitted. Sometimes you can see the number on it, other times it will be in the manual. Some Sony models just have the model number of the turntable as it. A Google search will come up with replacements and price.

Have you though of using a pre-amp? You'll probably need to go turntable --> pre-amp --> soundcard input to get acceptable sound

You do not need a driver for mac... just plug the usb cable into your mac... go to sound settings in system preferences and set USB to default audio input device... then install audicity... it is free and open source... play your record and hit record in audicity. done.