All the hardware - just a different circuit and I love the type 76 as an input tube. I never liked global feedback and I prefer triodes, so it was a logical change for me. Plus all the power supply and the coupling caps have been seriously upgraded. Still looks pretty similar on top. This is a Stereo 20 like no other, and I'm really looking forward to hearing it. I didn't want an amp that I didn't have much interest in listening to, which was the case with the original circuit. All my other circuits are 2 stage single ended ones, so this is basically just a push-pull version.