nad s300 , 200 watts 4 ohms?

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In general gain can be high or low regardless of whether connections are balanced or unbalanced. It depends on design of the equipment. If you have a particular piece of equipment that has provision for either balanced or unbalanced connections it may be the case that balanced connections yield higher gain, so that the volume control is turned up LESS. But some equipment with balanced interfaces automatically detects when inputs are unbalanced and adjusts its gain accordingly.

Whatever. One o'clock is a better place than nine o'clock for your volume control.
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Thank you Eldartford, I talked to the guy that I bought it from and he said the bal. mode is louder. So you get higher gain in bal. mode?

How far you turn up the volume has nothing to do with the power capability of the amp. It has to do with GAIN (volts out/volts in). A low power amp can have high gain, and under normal listening conditions play louder than a high powered amp, but will max out (clip) at a lower volume.