Integrating a vintage piece

I’ve made some giant move to upgrade the audio in my house...I now have a ton of orphan budget equipment from Best Buy from the 90’s to get rid of. Anyway, there is a piece I inherited from my uncle and has some sentimental value to me. I would just as soon keep it and not use it if it’s going to degrade the sound but I would like to integrate if possible. My favorite system I’ve put together in the house is a McIntosh MA5100 with my MCS 6100 turntable and PSB Image 5t speakers...I’ve also really enjoyed the sound of the Klipsch Heresy’s..just to give you frame of reference to the sound I’m attempting to achieve. I listen to rock and favor some brightness.

The piece I’d like to integrate into a separate system is a Lenoxx Sound SL-700 integrated amp. It has phono and aux in, A and B speaker out. If I were to pair this with an NAD preamp and either PSB Stratus or Klipsch Heresey speakers, will I be able to compensate for the amp being on the lower end? Is the preamp necessary? The only reason I mentioned it was because I thought I could run my components to it and plug it into the "Aux" on the Lenoxx. I’m listening to Vinyl and Flac digital files.

Any help would be great. Thank you.