Balanced vs RCA preamps

I always use an XLR connection because, in my experience, the sound is better (with volume matched) than the unbalanced outputs.

If the design is truly balanced, the higher output level from XLR can generally contribute to better sound (again, when volume matched) due to a higher SNR and lower noise floor in terms of THD+N. Apart from the well-known benefit of better noise rejection, handling the signal path separately for + and - significantly reduces crosstalk (see below).

The only potential adverse impact is that the output impedance of the XLR connection might be 2-3 times high. If you have an amplifier with low input impedance, such as a valve amp, you might run into impedance matching issue.

@atmasphere Usually XLR outputs have considerably lower output impedance than RCA outputs.

Where did you get this from? Have you done your homework before taking 10 seconds to write this? Let me do some homework for you, and you can do the rest to see if you can find anything to support your false statement.

You have to be careful about things you read like the specs above! I own the two of the Topping DACs; The 40 Ohm value is actually the two 20 Ohm output impedances put in series when really they should be in parallel, which would be about 10 Ohms.

@atmasphere  One should be very careful when interpreting the impedance of a true balanced XLR cable. The two conductors (pin 2 and pin 3) carry both positive and negative signals from the source to the load simultaneously, behaving like a parallel connection. However, because they are of opposite polarity, the signals travel in differential (v.s. common) mode. The resulting voltage is the so-called differential voltage, which is twice the amount of the individual phase voltage.  This explains why the voltage from an XLR port is twice that of its RCA counterpart.

Similarly, the resulting impedance, known as differential impedance, is also twice the impedance per phase.  The manufactural reports either impedance per phase or the differential impedance.  Hope this helps.