I have a new headphone amp (Schiit Midgard) with XLR outs and RCA outs. The XLR output puts out significantly more signal. Is anything wrong with the amp? If not, in the simplest language possible, why? Thanks.
Nothing wrong. XLR has twice the output of RCA because XLR has two signal wires where RCA only had one.
A little more detail: RCA has a signal lead and a ground. XLR has two positive leads that are out of phase to each other and a ground. That’s why XLR has three pins. When connected to a balanced amplifier, the difference between the two signal leads is amplified while anything that is the same on both leads is ignored. This is called common mode rejection and why balanced cables can be less noisy.
An additional outcome is since the difference between the two out of phase signals is amplified, the signal that gets amplified is twice the size of the signal that gets amplified in an RCA cable.
For example, if the signal leads are carrying 1volt, an RCA cable has a total of 1 volt on it while a balanced (XLR) cable has a total of 2 Volts, one signal lead with a positive 1 Volt and another signal lead with a negative 1 Volt. When the signals are combined, the difference between the positive 1 Volt on one lead and the negative 1 Volt on the second lead (total of 2 Volts) gets amplified vs 1 Volt for the RCA
Does this make sense?
I just realized you are asking about the connection between the amp and headphone. The above explanation refers to the signal coming into the headphone amp and not the signal coming out of the amp and going to the headphones so it probably off the mark of what you are asking.
The only thing I know about the difference between an RCA and XLR connection from the amp to the headphone is that with an RCA, the two speakers share the same ground lead while with an XLR, each driver has its own ground wire. I’ve noticed this produces a cleaner sound from my headphones but I’m not really sure about louder.
