Wavves frontman Nathan Williams has issued a second mixtape from Sweet Valley, his production side project with his brother Joel. Last month, Sweet Valley put out their debut tape, 'Stay Calm,' and now they are back with the 13-track 'Eternal Champ,' which features samples from various video game scores.

"We did the first [tape] really fast, in about two weeks," Nathan recently told Pitchfork. "The second one took a bit longer because we took a lot of samples straight from video game stuff, so we had to play to certain levels to get the sounds that we wanted. We did a take that's all from 'Ocarina of Time,' the N64 game."

"The record samples are a bit easier," he adds. "Most of them are just records that I already own, but some of it comes from stuff that's been posted on Twitter, or I'll remember a song I liked." Check out 'Eternal Champ' streaming in its entirety below.

Sweet Valley are currently on the road with Bear Hands and rappers GZA and Killer Mike on a North American trek dubbed the 64 Squares Tour. Sweet Valley are doing DJ sets during the shows, while Nathan will also be playing guitar for GZA during the Wu-Tang Clan member's set. That tour runs through an Oct. 26 gig in Asheville, N.C. Check out the complete itinerary here.

Listen to Sweet Valley's 'Eternal Champ'