Phono preamp for old Thorens / new Marantz

I just bought a Thorens TD150 MkII turntable from a friend. Has a Rega RB300 arm w/ Sumiko Blue Point cartridge. Was excited to hear some vinyl but discovered my Marantz SR5004 AV receiver has no phono input. Wasn't expecting to spend more money on this but evidently need a preamp. Any suggestions? Can't spend a lot, but don't want the quality of the turntable to get lost in translation to the receiver.