ruby amp buzzing

[dmm128]

So I just finished building a solid state ruby amp from runoffgroove. It sounds fine until I crank up the volume and gain. When I do that I get a sustained buzzing sound. Is this a pot issue or something else?

[Amp Kat]

Does it have a pot to adjust the balance of the output transistors ? Sounds like you're getting clipping on one side kinda like crossover distortion on a tube amp.

[dmm128]

Here is the schematic that I used.

Ruby

I posted a video so you can hear the problem.

[ame="http://www.youtube.com/watch?v=Q52_rIeipl0"]YouTube- Ruby amp high gain buzzing[/ame]