From Brian Willoughby Sent Thu, Jun 14th 2018, 05:02
From Brian Willoughby Sent Thu, Jun 14th 2018, 05:02
I=E2=80=99m not sure what you mean by =E2=80=9Cwith ground in the = middle.=E2=80=9D Can you explain? Do you mean physically placed in the = middle, or electrically in the middle? Note that unbalanced and balanced are both bipolar audio signals. By = =E2=80=9Cbipolar,=E2=80=9D I mean that the signal goes both positive and = negative in voltage. The signal on the =E2=80=98+=E2=80=99 wire in a balanced connection is = identical to the only signal in an unbalanced connection. The signal on = the =E2=80=98-=E2=80=98 wire is also identical except that it is = inverted in polarity. When one is a positive voltage, the other is the = same magnitude but negative voltage. For this reason, feeding a balanced = output to an unbalanced input with a carefully wired cable results in a = signal that is 6 dB quieter than a true balanced signal. The balanced = input combines the =E2=80=98+=E2=80=99 and =E2=80=98-=E2=80=98 signals = to create a difference voltage that is potentially twice that of either = wire alone, while also canceling out nearly all noise picked up on the = wire. You=E2=80=99re correct that TRS cables can carry either stereo (two = unbalanced) signals or balanced. The stereo signal could be line level = or headphone level. If you happen to plug a headphone output into a = balanced input, you=E2=80=99ll get very little signal because you=E2=80=99= ll be left with nothing but the difference between left and right. = You=E2=80=99ll probably also get some distortion unless your balanced = input can handle headphone power. On Jun 5, 2018, at 7:34 AM, Quincas Moreira <xxxxxxx@xxxxx.xxx> wrote: > Stephen, read Laurie=E2=80=99s explanation above. You do indeed = convert unbalanced to balanced with a DI box. Don=E2=80=99t confuse a = balanced signal with a stereo one. Both use TRS (3 wires) but stereo is = two unbalanced signals sharing one ground. Balanced is a bipolar audio = signal with ground in the middle.