New Studiomaster Power Amp Technology

First announced at this year’s prolight+sound exhibition in Frankfurt, the technology is designed to improve over current Class D designs. The new topology is said to combine design innovations with a Studiomaster patented ‘polyphase’ output stage. The effect is to provide “the equivalent sonic performance of a pure analogue design and greater efficiency than a Class D amplifier; enabling better sounding, more compact devices and power circuit integration, ” according to the company.

Here is how the company presents the new tech:

“At the heart of the Class AD Polyphase amplifier is a take on the ‘current dumping’ design of the 1970’s, where a high quality, low efficiency Class A amplifier operates in parallel with a bi-polar output stage. In the new Class AD design the ‘clumsy’ bi-polar output is replaced with an ultra fast switching Class D stage using MOSFET devices. To provide even higher apparent switching speeds, the usual parallel operation of the MOSFET devices is replaced by Studiomaster’s patented Polyphase mode, whereby pairs of MOSFETs operate at different times, sequentially. This provides the opportunity to overlap the devices when the load is greater or the signal is bigger. The net result is a far higher apparent switching speed and a reduction in the required output filtering and switching artefacts, improving sound quality and reducing weight.”

Additionally in the Class AD topology, the Class D circuitry becomes inactive at very low signal levels (with only the Class A component operating); thus, at small signal levels the inherent sonic limitations of Class D amplification are eliminated and the system runs as if it were a high quality, purely analogue device, according to Studiomaster.

The technical reference document, describing the new Studiomaster Class AD Polyphase development can be downloaded at https://www.studiomaster.com/files/ClassADamp_techref.pdf