Yes No EAR acute cd player into my pathos tt ?.

You should have a routine which you do not vary from when it comes to set up of a new system and in which you are using a source as volume control. You should always set the volume to minimum on all components. Some amps also have output controls, so they also would be set to minimum. Always work from ground zero toward your listening level. It's the only way to be absolutely sure you will not blow up something.

Also, every single time I establish a new rig I always have my hand on the remote's stop button when first beginning play. No exceptions. I have set up some rigs a dozen times, but still hold the remote's stop button for the source. Why? Because we all make boneheaded mistakes and we don't want that one moment of thoughtlessness to be our undoing.

No exceptions: Check cabling two or three times. Remote in hand with finger on stop button.

I also have my hand on the power button when firing up amps, just in case. It's not a perfect world and preparedness to act can one day save a lot of pain. :)

Right. As Douglas said, make absolutely sure the volume on both the Acute and the Pathos are ALL THE WAY DOWN before you begin playing. If you trip up there, you may find yourself blasted into the back wall of your listening room. Quite an unpleasant experience.

Yes, I do this all the time with two Pathos Classic One MkIII integrateds running mono. You can set the output of the player to Max, then control the volume from the integrated.
Just be sure at initial setup that you start with level down to minimum on both components and adjust accordingly. It's the safe, sensible way to establish the control of the system.

I once had an EAR Acute into an EAR 859 integrated amp. It worked just fine.