True bi-pass Question

If an effects pedal has true bi-pass will the battery still drain if you leave the cord plugged in with the pedal turned off ?

Not sure if all but many pedals do that. Mine does it.

My understanding is that the SIGNAL is bypassed around the circuitry when in the off position. The power is still drained when a jack is in the input, though.

... The power is still drained when a jack is in the input, though.

Yes indeed.

Yes, for most pedals. The input jack is usually a TRS connector (Tip, Ring, Sleeve).

The tip is the applied signal, the ring is connected to system ground, and the sleeve is wired to the battery negative terminal. When a plug is inserted, the sleeve and ring are joined (since the input plug is mono, or Tip and Ring), which applies the battery negative terminal to ground.

Even with true bypass, the circuit is still "live", and, therefore, drawing battery current since the positive battery terminal is usually always connected.