M1 or M1A when combining with second source

[M1A]

I want to combine my M1A with a soundboard transducer (SBT) pickup. I would prefer to use my M1A since A) I already own it and B) I like having the volume control. Can I use the M1A or would I be better off using an M1?

Do I need to get something like a Switchjack to combine the two pickups? It looks like the ring is already taken on my M1A jack.

Thanks,
Jon

[Bryan McManus]

It's a whole lot easier to combine the passive M1 with another pickup. For example, the passive M1 can be added as an auxiliary signal to any of our endpin preamp systems such as the iBeam Active System(iBAS) and Element Active System(EAS). It can also be used in place of the Element in our iMIX system, as used by Tom Petty, for a very rich and full sound with minimal alteration to the guitar.

With the M1A, you have to wire in the power switch contact and, if you're combining it with an active system powered by 9V, you'll have to remove the 3V battery from the M1A and tie its power circuit to that of the 9V. It's more complex and more permanent than if you were to use the passive M1.