can i mate my receiver mac 1700 as a pre amp to my mc 275 amp?

It appears that the 1700 does not provide output jacks for its preamp section.  Therefore I believe the only way you can use it as a preamp would be to connect a speaker-level to line-level converter between the 1700's speaker outputs and the 275's inputs.  Such devices can be found via a Google search.  You would want to make sure that the converter is rated to handle amps capable of providing 40 watts, plus some margin.

Of course with that approach you would essentially have two power amps as well as the converter in the signal path, which isn't likely to be optimal from a sonic standpoint.

Regards,
-- Al

   Hello bamboo,
  
     I believe you've reached a crossroads on your audio journey.  I suggest you need to decide whether you want to retain the convenience of a receiver, along with its inherent limits and compromises on sound quality performance, or you want to upgrade to higher potential sound quality performance through the utilization of separate preamp and amp components in your system.  Contemplating using your receiver as a preamp seems to indicate uncertainty and avoidance of making this basic but important decision.  
     I recommend and encourage you to take the adventurous road on your audio journey. For example, you could sell your receiver, use the funds to buy a high quality and well matched new or used preamp to mate with your 275 amp and begin exploring and enjoying the wonderful new world of increased higher audio system performance that well researched and carefully chosen separate components are very likely to provide.

Best wishes,
     Tim

Appreciate your feed back!
looks like a preamp is in my future!
i just bought the Mark IV 275 through you!
what in your opinion would be the perfect preamp for that amp🤷‍♂️Tim