Power for Conventional Control

Why not use your DCS remote and one of the two variable channels on the TIU?  I have that wired to my mainline, that's the way I run conventional stuff here.

Honestly, I didn't know you could do that.  But I don't have a DCS remote or TIU.  I have the DCS Remote Commander and a DCS Explorer.  All the starter set stuff.  I've been waiting for the new Wifi stuff from MTH before I take the plunge to big boy DCS.

If the MPC train set came with a blue 50-watt transfomer, I would personally pick that over the Z750 or the CW80.  I would also recommend Lionel's postwar 1033 and RW-type transformers for conventional operation.  These are quite affordable these days.  The only caveat is that I would add an Airpax external circuit breaker between the transformer and the track, as cheap insurance.  My $.02.

Thank you for the response, I will follow your advice!

Switch either track loop center rail between your MPC sets power and DCS Explorer power.  See my website page, Toggle Track Power Between Conventional and DCS or TMCC .
This "how-to" photo on that page shows how to switch one loop between an AC transformer and DCS TIU.

(Be sure transformers are phased.)

That's a good idea, I never would have thought of doing something like that.

I've got 2 mainlines and DCS / Conventional (MRC AH601) that can power either / or by using 2 toggle switches. I've use a DPDT; one for common and hot, though the SPST will work as well. All the lightning and switches are controlled by a separate ZW providing varying levels of voltage. They all share a common ground, i.e. phased together. Currently working on using rectifiers (LED's) and relay's to control the crossing gates, flashers etc by using the ZW power them triggered by whichever AC is actually on the tracks.  That keeps the accessories operating at a constant voltage regardless if the track power is conventional or not. Below is a neat diagram I found showing the use of AC and DC control together. Some folks may find this useful.