Woops, brain fart. I forgot about the shared design.Soundstream TN2.600D is the same board inside as PPI P600.2. Onlinecarstereo.com has them. Also Polk Audio Class D amplifiers use the same (Nakamachi) board design, although the individual internal components are different. The Polk amps have pretty much the same watt output as PPI/SS, even though the 2-channel Polk D2000.2 is rated slightly lower. I saw a test of avtozvuk.com showing 2x150watt output at 4ohm with 12.5 voltage, so it should be same as PPI and SS with 14.4V. I don't how how these compare with the more "noble" brands like Boston Acoustics for pure SQ material, but these class D amps have amazing price/performance, size, great for subwoofers or power-hungry speakers.