A:
Thanks for the question.
There is a USB input, and a single 3.5mm input on this model.
If your turntable is powered (and doesn't require phantom power, or power supplied from the amp, which is common in many older turntables), it may work with an RCA to 3.5mm input, which is the only AUX (auxilary) input on the DA-E750.
The cassette deck could be simply converted with an RCA-to-3.5mm male connection, but not at the same time as the turntable.
You can use the DA-E750 as a main component, but if you don't want to swap out the inputs (turntable and cassette player), then you might either consider a separate mixer, or a different device that has more inputs.
You can have a Best Buy salesperson show you the various models and help you decide if this will be the best option for you.
The DE-A750 is a cherry red finish, and the DE-A751 model is black.
Thanks for your interest in Samsung products.
--Mr.Samsung