The Amplifier Class XD has a British patent owned by Cambridge Audio. The term XD comes from Crossover Displacement, which means this amplifier is based on a Crossover Displacement Technology. This technology removes a certain amount of distortion without collateral compromises. It first appeared, many years ago, in the Azur 840A integrated amp, and has a Class B output stage merged with a Class A output one. Both work at the same time, which allows relocating the crossover distortion away from the zero-crossing point. The combination of the two operates with a Class A at a lower level and with a Class B at a higher level. However all, the have no association with Class AB.
Amplifier Class XD: the Pros
The Amplifier Class XD has many benefits because of its particularly low distortion. Class A amps are extremely efficient, but they tend to have greater levels of distortion because of the delicateness of the audio signals when crossing a transistor. In contrast, Class XD usually moves the controlled distortion away from the zero-crossing zone, a place where the transfer functions of the transistor pair more evenly. As a result, the distortion of the sound is far less perceived.
In addition, money-wise, it appears to be cost-efficient.
The Cons
The sound of an Amplifier Class XD appears to be amazing, but it doesn’t seem to be very efficient. Differing from this, you can find Class A monoblock amplifiers in all shapes and sizes. It’s even possible to find them as small as a coffee table! In oposition, Class XD amplifiers require a huge amount of heat, generally produced by Class A operations.
Some Final Information on the Amplifier Class XD
The combination of Class A amplifier, with the efficiency and power of Class AB amps seems to have broad audible benefits for most speaker setups. It’s worth mentioning that the 851A provides 120 watts for each channel.
