A friend of mine picked up an ION record player that has either USB or RCA with built in pre-amp. My natural instinct is to say RCA thru his audio break out box, but maybe USB is okay these days.
Opinions please......
If you use the USB feed then you're relying on the quality of the inbuilt A/D converters and the preamps. Taking the signal from the RCA connections you're only relying on the inbuilt preamps.
Given the quality of similar units I've seen it'll probably make little difference either way.