PV 6 BT getting different output with the same source between channels 3/4 and 1 and 2

[peaveychiq]

So I have a stereo guitar amplifier out signal that I'm trying to get into the mixer. If I put it in channels 3/4 the sound is reduced, very little volume. However, when I stick it onto the 1/4" middle of the XLR of channels 1 and 2 separately, the sound comes out at full volume.

All the knobs are identical in terms of volume.

Is there something that I'm missing or doing wrong ??

[jim h]

The 3/4 inputs are unbalanced inputs, while CH1 and CH2 inputs are balanced. With the unbalanced inputs you are losing up to 6dB of your input signal on each channel.

[peaveychiq]

Wow! I did not know this... Why is that? (About the 6db loss).

Also, would I get that loss in db back if bb I switched to unbalanced cables?

Also, why would 3/4 be unbalanced and 1&2 be balanced? What is the philosophy/thinking behind that?

[jim h]

You can easily google the difference between balanced and unbalanced. Sorry, more typing than I'm inclined to do at the moment and it might be easier to understand visually.

On channel 3/4, the inputs are also paralleled with the 3.5mm stereo jack, which is unbalanced. To make the 1/4" balanced would have taken another op-amp stage and we are pressed for space on a mixer like the PV6BT.