Mesa Bass Prodigy & mpulse together questions??

The slave out of the mpulse goes to the fx return on the Prodigy. That should turn your Prodigy into a simple power amp with all the preamp action coming from the mpulse.

Since the mpulse has level control you could potentially turn that way down and go into the front of the Prodigy instead.

If you get a hum I think you are stuffed from ground loop syndrome.

 

The front input on the Prodigy is instrument level, the effects send on the M-Pulse is line level.

 

Because there were unknown mods done with effects loops over time, especially by the DIY community, I can't be sure why you got the results you did.

 

Try working the slave out level control back and forth.

 

First, you always keep the cab connected to the Prodigy when playing thru it.

If your first attempt using the slave out jack didn't work, then use the effects send jack from the MPulse to the effects return jack on the Prodigy.

 

Also, when using your MPulse all by itself and you don't have any effect pedals or modules plugged into the effects loop, then I wouldn't leave that mini toggle swith to "on".