The legendary producer - who worked on Michael Jackson's 'Thriller', the largest selling album of all time - said he was lucky to be able to recruit Amy to work on his upcoming album of covers 'Q: Soul Bossa Nostra' after a chance meeting at Nelson Mandela's 90th birthday party, which she performed at in 2008.
Of her performance of Dinah Washington track 'It's My Party', recorded with Mark Ronson, Quincy told RollingStone.com: "She's a smart little girl. What can I say, man? Nobody sounds like her. She's been going through a lot of stuff, but she came on through, man. Everybody was saying, 'You'll never get her' and all that stuff.
"You know how the press is today - it's lethal, with all the haters and negative s**t. But she and Mark came on in and they did it. She has a great voice. She's from another planet."
Meanwhile Mark, who produced Amy's breakthrough album 'Back to Black', said he will not make a decision as to whether he will work with her on her long delayed third album until he's heard the songs she's written for it.
He told the Metro newspaper: "I'm not sure if I'll definitely produce her new album. Whenever I'm producing a record with Amy or whoever, it's always about the songs, so you have to hear the songs before you decide what you're going to do.
"Obviously there's a chemistry in the record that we made together. I hope if we did something together again it would be as good."