Green Amplifier Technology Comes of Age


This is the "Greenest" thing I have.

Power Amplifiers for Hi-Fi stereo systems come in a variety of types. Audiophiles often prefer tube or solid state amps, while some like hybrid amp designs.  Having used both tube and solid-state amplifier designs has given me an appreciation for both approaches. Class A, AB solid state*, and tube designs are often the most used amps for high end music playback. I’ll admit that tube amp designs can impart a beautiful tonality on the music, but sometimes the added harmonic content is too much for my tastes.

Although Class D (pulse width modulation) amps have been around since the mid 70’s, they have been mostly used in consumer grade electronics and live sound installations. Many of the home theatre-in-a-box and recent iPod sound docks** also use Class D amplifier technology.

Being energy-efficient, physically small, and running cool makes class D amps very attractive to the consumer market. High end audio companies also took notice. Companies like Lipinski, Bel Canto, NuForce, Wyred for Sound and CI Audio have all worked at making the most musically satisfying class D designs.  The ability to drive most speaker loads and exert extreme control over the speaker drivers make class D very attractive indeed.***

Sonically, I have experienced mixed results with audiophile class D amps. While quiet, fast, and revealing, they can also sound a bit dry or stark. Comparing these current generation class D amps to Class A and AB designs has kept me from recommending any one class D amp for audiophiles.

The Dutch Masters?

A small company in The Netherlands, Hypex, has taken control of the current class D amplifier scene. Hypex  builds many OEM Class D subassemblies that make their way into audiophile amps. A new generation of this Class D amplifier called Ncore is supposed to “surpass the best linear amplifiers – in every way,” according to Hypex. Luckily, 6moons (audio review site) had a chance to try these new modules and speak with the designers. You can read the full article here.

  1. * Audio Amplifier designs explained here.
  2. **Hypex is also known for designing the Class D amp and power supply found in the Bower &Wilkins Zeppelin iPod dock.
  3. ***This is refered to as the Damping Factor of an audio amplifier.