[Interested in Apex/RK controlled d120's?]

Well I have a bunch of 741 Op amps.  How would one do it if not tying the negatives of both supplies together?  How is the Op Amp input to be negative referenced on the Op Amp?  + signal goes to the Normal input, where would the - Apex line go?

[Interested in Apex/RK controlled d120's?]

Hi all, new here, not that new to Reefing.  150g for 4 years now, and a few 45g for a few more.  

 

I'm wanting to ditch my DIY LED's for these D120's  Planning 3 on my tank.  Now I'm sure the Apex would be fine with 1 light, 1 channel per VDM channel,  but 3 lights, I'm not so confidant.  I cant have my Apex fry as I work in camp 3 weeks at a time and no one would be able to figure it out or repower my tank untill I return.

 

SOOO, to my question.  I am planning to run a OP Amp per channel on the lights.  And incorperate a pot for setting that channel Max brightness, yet keep the Apex program 0-100% for dimming.  I have sketched what I think should work.  Been about 20 years since I played with Op Amps so wanted someone to check it over.  Plan on mounting the Op amp in the light housing.  WOuld I be able to run power from one of the drivers or should I add a separate 10V supply to power the OP?