The Maroon 5 frontman and his wife, Behati Prinsloo, bought the massive pad from "Will and Grace" creator Max Mutchnick just over a year ago for a cool $35.5 million ... and just put it back on the market.

We're told the couple put $7 million into a complete remodel with a world-famous designer and are now listing it at $47.5 mil. Do the math ... pretty nice profit for a year's work.

The estate -- listed by super real estate agent Kurt Rappaport -- is located on an iconic street in Bev Hills and is over 10,000 square feet of awesomeness ... including a gym, spa, guest house, resort-like pool, 2 kitchens (one just for the chef), a professional screening room, 12 bathrooms and 5 bedrooms ... including a 2,000 sq. ft master suite.

Oh, and Pete Sampras used to live there too, so it also comes with the famous tennis court he installed.

We broke the story ... Adam and Behati recently bought Ben Affleck and Jennifer Garner's former home in the Pacific Palisades for $32 mil, so don't worry about them being homeless.

Real estate is kind of a thing for Levine -- he sold 2 other homes last year in Beverly Hills ... including one to John Mayer for $13.5 mil.

No word if any celebs are interested in Adam's new one yet ... but we're sure Rappaport will get a ton of calls.