You certainly do not have to spend $400 on a pair of xlr cables to find out!
Get an inexpensive pair (well under $50) and try them out.
The fact is that the xlr connection has greater or lesser benefits depending on what your devices do with such a signal once they receive it.
The dacmagic is supposedly a fully balanced DAC, and its output voltage at the xlr outputs is twice that of the RCA outputs. In principle, it's a cleaner signal.
I don't know enough about your amp/preamp to see whether the xlr will make much of a difference with that.
Get an inexpensive pair (well under $50) and try them out.
The fact is that the xlr connection has greater or lesser benefits depending on what your devices do with such a signal once they receive it.
The dacmagic is supposedly a fully balanced DAC, and its output voltage at the xlr outputs is twice that of the RCA outputs. In principle, it's a cleaner signal.
I don't know enough about your amp/preamp to see whether the xlr will make much of a difference with that.