The stereo 70 was an excellent amp when they went for 150$. I have one and have replaced the: Driver Board(sound values)125$ All tube sockets w/ceramic 80$ The power supply w/Curcio's upgrade90$ power supply choke 20$ various jacks and resistors and caps 50$ All in all it now is a very good sounding amp but for approx. 500$ Now I see them going for 400$ just for the amp so do the math. The stock units are not so fine sounding but you can replace certain caps and other parts to sqeak by but I would look elswhere. I use it when I need power the amp drives the PI 4's to very respectable levels. Good for backyard parties!