What are XLR inputs??

Balanced connectors will also get you a few more DB.

Willy -

XLRs are a type of connector with three pins in a round shell. They're typically used for carrying a balanced signal connection, though some manufacturers who have XLR connectors on their gear do not necessarily have balanced connections - they simply have a single ended connection wired to the XLR connector to make their single ended gear compatible with other pieces that have XLR connectors.

If the designed cut corners when designing the gear, the XLR connector will have double the output of a standard RCA connector. If properly designed, the unit will have the same output on RCA and XLR.

XLR inputs are balanced inputs. Here is the techie version (I am sure that I will be corrected if I am wrong.)

For each channel, say the "left" channel, balanced amps and preamps have separate sections to amplify the positive half of the signal and the negative half of the signal. This is one way of looking at it, in reality they an amplifier with positive gain and an amplifier with negative gain, each is closely matched to be the inverse of the other. The output is the differnce between these two amps, and that is why in theory balanced amplifiers should have twice the output of single-ended amps.

For the connectors, one wire connects to the + gain, the other to the - gain, and you are and ready to go. So the XLR/Balanced inputs have 3 wires (one for + one for - and one for ground (neutral)) and 3 contacts to carry the signal to the balanced circuitry.

Why is this good? Because any noise that is common to the system will be amplified in the + section and amplified in the - section, and when you take the differnce for your output the noise cancels itself out. This is called "common-mode" noise rejection. This is also why long runs of balanced cable are better than long runs of single ended cable. Any noise picked up equally by the wires in the cable will be canceled out when the amp looks at the difference signal between the 2 cables.

Just because something has balanced connectors does not mean the circuitry is truely balanced with the separate internal amps I just mentioned. Some coponents just convert signal from the balanced cable into a single ended signal with a cheap op-amp and use a traditional type of amp. If you are considering BAT gear that would be truely balanced, as are the Sonic Frontiers preamps.

good luck!