Switching bipolar power with audio jack - Using MOSFETs?

[Electric-Gecko]

For most of the pedals that I'm building, I want to use bipolar (dual) power supply, so I was happy to find this old topic about how to make the bipolar power switch on when an audio cable is connected (as single-supply pedals do with a very simple mechanism).  They had 2 different implementations of this on that topic, which both relied on bipolar-junction transistors.


Wouldn't it be better if at-least 2 of the transistors in either version (the PNP & NPN connected directly to the battery) were replaced with enhancement-mode MOSFET's? I have no experience using MOSFET's, but I read that they can have way more resistance when turned off (into the Megaohms & beyond), and that they need way less current at their gate.  Wouldn't this mean that it would drain less battery with MOSFETs, both power on and off?

But how could this be made with MOSFETs?
It would be nice if someone could post a schematic.  It would also be nice if you suggested which (somewhat obtainable) MOSFETs to use, as I am new to them.

[R.G.]

It's not necessarily better in a practical way. MOSFETs may be less conductive (more "off") than bipolars in some very low current situations, but for battery switching, they're fine. The battery's self-discharge is way bigger than the leakage through an "off" bipolar, and that's enough.

The first implementation of that setup was actually with MOSFETs. They're simpler to turn on and off slowly, with resistors, which is how that circuit tells the devices to switch. The circuit comes from a time when small MOSFETs were on the order of $0.50 each, far more expensive than a $0.05 bipolar, so I reworked it to use bipolars so it would cost less.

I could go try to dig out the originals, but there is no practical difference in performance.