Forum

[godchuanz]

Just to clear up the balanced/unbalanced signals issue:

- Unbalanced: you take the signal from one end to the other. Any noise picked up in between is present at the other end, e.g. from guitars to most effects pedals, to amps etc. This means, the longer your cable, the higher your noise. Since you only need to transmit 1 signal, a MONO cable (TS) will do. If you plug in a stereo cable (TRS, XLR if it fits), only one of the channels will be used.

- Balanced: you take 2 copies of the SAME signal from one end to the other. It gives cleaner sound. The trick is, one of the signals is phase-inverted. When it goes through the cable, they both pick up very similar noise signatures. So when the 2 waveforms are summed after noise, the signal cancel each other out, and only the noise is present. You can then invert the noise and apply it to the uninverted channel, to achieve noise cancellation.

Ignore this part if you don't understand. But for those who see things mathematically,
1) let signal be x(t)
2) inverted signal will be -x(t)
3) let noise be z(t)
4) At the end of the transmission, the signals will be:
a) x(t) + z(t)
b) -x(t) + z(t)
5) Summing them, you get 2z(t)
6) Apply noise cancellation: x(t) + z(t) - 0.5(2z(t))
7) End result: x(t)


Since balanced connections require 2 signals to be transmitted, you will need a stereo cable for that, e.g. TRS or XLR cables.

I hope I helped clear up some fog!

edit: By the way, impedance has little to do with balanced/unbalanced signals. It has got more to do with signal strength, and even that is not really accurate.