John Mayer johnhouse.jpg

X17online has the first pix of John Mayer's new $10 million Hidden Hills mansion (that's the equivalent of $20 million in regular, non-Valley LA currency) and it's a whopper!!!!

Dude's supposedly leasing the place to use as a recording studio -- but he must be housing the entire band and their families there too!

The place has got a theater, eight bedrooms, a six-car garage, and even room for horses!

So the question is ... will Jen spend the night???