It’s great that you are asking a question about a new hobby but you also need to know some of the people you asking and if you should believe them or not.
ASR is a joke. Stereophile is a joke, tell me a review of any product that had a negative outcome, every product they review is the best of the best. Also, jasonbourne posts are all the same, if you spend more than $500 you spent too much.
Now, to answer your question about if you need a preamp or can you hook up the dac straight to the amp, it all depends. If you go jasonbournes way and go cheap, you are most likely going to need a preamp because they will go cheap on the volume control section and it will be noisy AND the dac might not have the range to control the amps output. If you go with a much better dac (I paid over $8000 for mine), it has a quiet volume control and provides an attenuate button so you can properly control any amp. I sold my 5-digit preamp when I purchased this dac because my system sounded better without it and my volume setting is in the sweet spot of control.