Power amps have always been heavy, mainly because of the massive transformers and huge banks of capacitors needed for high-power operation. In fact, six conventional power amps in a rack can easily top 250 pounds. The same number of EPX Series amps come in at just under 134 lbs./61 kg, and they pack all the power of their conventional counterparts!

The secret to the EPX series' incredible power-to-weight ratio is their use of a switching-mode power supply combined with Class-H topology. Switching-mode power supplies work on demand. Instead of constantly working at full power and dissipating excess power as heat, they only ramp up the power output when needed-thousands of times per second. Considerably more efficient than traditional power supplies, switching-mode power supplies are small and light, yet deliver ample power.

Think of a Class H amp as a car with two engines (in amps, you call them "rails"). One engine runs all the time. The other runs only when musical peaks demand extra power output. An EPX Class H amp only generates a fraction more power than is immediately needed while the output stage operates at its maximum efficiency all the time.

And just like in today's hybrid cars, the efficiency of this dual system is far greater than having one engine or rail that must operate all the time. EPX amps don't waste power. Class H amps don't waste power, require much smaller heat sinks and much lighter power transformers.