Strange clipping from TDA2030

Hi! I'm hoping for a diagnosis of a horrible sound coming out of a TDA2030, which will run my first Amp build. Eventually I plan to run two of them in bridge mode, but I am just testing everything first. I built my power supply almost exactly following that of the fender frontman 10G, but at +/-12v for the dual supply. I'm running that power into a simply unity-gain buffer on a TL072, and then that runs into the test circuit from the TDA2030 datasheet. That runs into a Carvin redeye 4x10 cab. I'm just using my bass' volume knob to control level while I make sure everything works.

Here's the thing: everything sounds good up until I hit about 50% volume out of my bass. Then I get this terrible clipping noise that kicks in right at the attack of a note, then disappears. I've recorded a sample and will link it in the comments. I slowly turned up the volume up on my bass so you can hear it kick in.

Any thoughts on what this is and how to solve it?