I'm sorry, but I have to disagree with your statement that "They have low parasitics, but that only applies at high frequencies, not audio." The statement is completely inaccurate and misleading. The Class-D output stage runs at high frequency (our GaN modules at 800Khz), and the output MOSFET, whether Si-based or GaN-based, must have extremely low switching losses to operate efficiently. Any "parasitics" impact the efficiency and purity of the switching waveforms, causing slope variations, overshoots or undershoots during the transition. All of these factors affect the quality of sound reproduced. To better understand the fundamental principle of operation, it would help to look at the principle of operation of a switching amplifier (CLASS-D). Many articles are available online that can help you understand this better.
Gallium Nitride GaN Class D Amplifiers
In my recent research for a possible upgrade to my current amp (Benchmark (AHB2) I was reading about the new higher end design for Class D. I'm very interested in learning more about these new GaN(Gallium Nitride) designs. Three companies are offering some very well reviewed products and they are not going crazy with Watts per channel:
Orchard Audio offers a 250 watt Amp
AGD a 100 watt
Atmos-Phere also a 100 watt
What's interesting is while Orchard is a new company AGD and Atmos-Phere have been around a while producing high end Tube amps. In almost every review it is noted how these newer designs sound like Class A or Tubes with all the benefits of Solid State. One reviewer couldn't go back to his tube amps after extended listening to the Orchard. No wonder AGD and Atmos-Phere are getting into this technology. It's very exciting as these amps are highly efficient turning over 90% of the power they draw into sound compared to about 78% with A/B designs and I believe even significantly lower for Class A. They run cool and usually weigh between 10-28lbs. I plan to do more investigation. Small size and light weight with decent power is very attractive. There are also mono block offerings for more power if needed. These are not cheap Class D products. They are well designed and constructed.
Orchard Audio's base model is around $2700and their Dual mono version with larger power supplies is $5500.
Both AGD and Atoms-Phere are $5000
Mono blocks for each are about twice the cost.
Has anyone had any experience, demos, etc ., with these types of GaN Class D amps?
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- 75 posts total
- 75 posts total