Can I use an 'Integrated Amp' as just an Amp?

This question comes up because my complex Speaker setup (Infinity RS-1B) seems to require me to go out and buy a separate preamp to feed into the crossover, and then separate 2-channel amps for treble and bass speaker towers. So, for those who haven't seen them, there are a total of four towers, and you supposedly need a minimum of two 2-channel amps to power the setup properly.

I have a decent 2-channel integrated amp and I think I can use that on one set of the towers. (For the other set I have a 2-channel SS amp that is getting some minor repair).

The Integrated is an Arcam with a "direct" button which I think knocks out most or all of the pre-amp functions. I've always loved this button, if only just for access to some attempt at simplifying my electronic path and sound.

Furthermore, if I do go out and buy a 2-channel amp, some of the ones I see that I want to consider are actually "integrated" amps that have many preamp functions. For example, I'd like to consider some of Jolida's Integrated Amps (which they seem confusingly to call just plain "amps" sometimes), and then if someday I want to use them in a simpler system I could.

But I don't want to buy a nice Integrated Amp for this project only to find that it's not appopriate to use for something like this. (This is all aside from the Infinity Phase-Inversion-concern wierdness that goes with these speakers).