The main purpose of the USB turntable is to convert the old vinyl records into digital music files. While buying a turntable, one must think of the following aspects:
Output - The most important consideration is to think of the type of output needed. Go for a design that has standard audio outputs. This lets you to plug them into your stereo system and other devices, and not only limited to connecting the turntable only to the computer.
Control - The next important consideration to be thought of is control. For more convenience, one should look for a design that has an automatic play feature. These do all the work so you need not to be messed around with starting and stopping the record.