Jumper Cable or Foot Switch

[ignition]

Would running a switch like a Lehle Little Dual be the same as using a jumper only... foot switchable?

[Big Mike]

Not quite.

With an A/B or both, your either choosing one channel or the other, or both in parellel.

With a jumper you're actually cascading the channels. It's a different sound, different gain, different response.

[SDM]

If taking about a JTM45, 1959, or 1987 style amp here, and jumpering the inputs with a cable, then the jumper cable does just put the inputs in parallel, it does not cascade them.

The overall effect is slightly different when using a jumper cable vs. an A/B box (that simultaneously feeds both inputs) due to the way the switching jacks work, but both will just parallel the input stages, and work very similarly.