Does using XLR cables (double voltage output) mean I can use lower powered amplifiers?


Hi

Does using XLR cables (at 4V output from most dacs) vs RCA cables (with 2V output) mean that I have doubled the gain hence I only need half the power from amplifiers?

Just as a background I am looking for tube amplifers which typically are less powerful compared to solid state amplifiers. So I was wondering if using XLR connection rather than RCA mean that I can venture into lower powered amplifiers?

Or does the voltage input from the dac not matter/affect the power that a amplifier needs to drive the speakers?

Thanks!

Regards
Ben
thegreenman

Showing 1 response by cakyol


No, it does not work like that.

All XLR systems do is provide DIFFERENTIAL signals. This reduces noise considerably but does not change the gain and/or power transfer.

Below is a VERY simplistic explanation. The detail is much more complex but this is to give a very basic idea:

In an RCA cable (or any NON differential system), if you were to feed 2 volts of signal, typically it would be 2 volts on one cable and 0 volts on the other. If there was some noise of say 200 mV, then you may get 2.2 volts and still 0 volts, hence totally passing the noise to the amplifier.

In a differential amplifier, the same voltage will appear in both the cables as 3 volts and 5 volts (difference of 2 volts). With the noise, BOTH the terminals would be raised to 3.2 volts and 5.2 volts. Since the system works on the DIFFERENCE of the voltages, ie, 5.2 - 3.2 = 2 volts, your noise gets eliminated to a negligible amount.

Hence the much better noise rejection of an XLR differential system