Balanced vs RCA preamps


How important is it that your Pre-amp has both balanced and RCA capabilities? I’m shopping for another pre, most likely tube, and it seems to make sense with any future component that it offers both XLR and RCA. And to further complicate the search finding both these features plus remote limits the offerings for both tube and SS particularly tube.

 

kckrs

I have not owned a single ended tubed preamp that did not produce unwanted noise over the cabling. I made the switch to an ARC preamp and was able to put balanced cables in all the way through from DAC to amp. Best move I ever made to significantly reduce noise and hash. Now I have a black background. If there are single end tubed preamps that are quiet, I certainly didn't have any luck finding them like some others have.

YMMV

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.