they replaced them with the A-series to replace flaws that the E-series had. They're the same price and wattage as the E-series. The boards are nearly identical, too. The only differance is that they have different, more massive heatsinks (the e-series would overheat too easily due to a small heatsink), and when they overheat, they won't shut off. Instead, the volume rolls back until the amp reaches an acceptable temperature.