Hehe, it actually has that pointed metal rod (can be seen in the picture), that goes onto the end of the Microphone Stalk. Works very much like a screwdriver, except a bit more high-tech. I haven't used it, but it'd be perfect for finding engine noises while stationary.
I'll check later today what voltage this thing puts out. It just uses a 3.5mm Mono connector. The volume is adjustable, via a scroll wheel. So even if it amplifies up to the supply voltage (a 9V block battery), you could carefully set the volume to be at 5V Max.
The Tactrix has a 2.5mm Audio Input Jack for logging. That's an analogue input isn't it? It then converts to digital levels iirc. Would that work for what you need?