I will start with some information about two audiophile Class-D amplifier pioneers - Tripath and Hypex. In spite of the disdain displayed by some traditionalist audio enthusiasts for Class-D, these pioneering efforts were based on rigorous engineering, not unicorn fairy dust and other subjective exotica. But there is still much research and work to be done.
Tripath Technology was founded in 1995 by a Silicon Valley Ph D. electronics engineer, Adya Tripathi, who had previously held senior positions with AMD, HP and IBM. As far as I know, Tripath was the first company to offer true high-fidelity Class-D amplification, which they called "Class-T" and trademarked the term for marketing purposes.
The fact that Audio Research, Bel Canto, Sonos, Apple and other high-quality technology companies designed and sold Class-T amplifiers speaks to the role of Dr. Tripathi’s technology in moving Class-D up into the realm of high-fidelity, in spite of its inherent flaws and artifacts. The continuing popularity of the remaining NOS Class-T chips and modules 13 years after the company went bankrupt is testament to the quality and performance of the development of that technology. Unfortunately, when the big semiconductor companies like TI moved into Class-D chips for mass-market A/V electronics in a big way, it killed Tripath and Class-T. All that remains is lots of inventory. (Three years after Tripath went belly-up, Dr. Tripathi founded another Silicon Valley tech company, "Tula Technologies" that is also into saving energy. Rather than audio, Tula's software products are DSP for ICE (internal combustion engines), including a pairing of digital signal processing and sophisticated powertrain controls. This technology can enable the removal of 1 ton of CO2 per vehicle per year and boost MPG by 7-15%.)
Although there are many poor implementations of Class-T amplification as well as some excellent ones, I am not aware of a “bad” Hypex amp - the surviving notable Class-D amplifier manufacturer. Hypex Electronics is a Dutch company that was founded in 1996 to make plate amplifiers for "live sound loudspeakers." In 2003, Hypex executives recognized the movement of Class-D technology towards market dominance, so they developed their proprietary “Universal Class-D” variant and called it “UcD.” Just like Tripath’s Class-T technology, UcD lives on more than a decade later, but unlike Tripath, Hypex is still in business. Then NcD line was joined in 2008 by a newer variant, the Ncore series of modules, which add a high-quality switching power supply to the module. UcD amps with switching power supplies, and Ncore amps with on-board power supplies are much lighter than many “audiophile” UcD-based amps with heavy iron-core linear power supply transformer(s) present. (Of course, some people prefer linear power supplies, and I am guessing that Hypex will continue to manufacture both both UcD and Ncore products.)
So, while Tripath tried to compete in the mass market electronics sector, Hypex appears to be focusing on high fidelity and smaller specialty markets - audio enthusiasts/audiophiles, DIY, and pro audio – and they are apparently succeeding. They actually have two marketing/sales divisions – OEM and DIY. OEM is factory direct, and DIY is via DIYClassD.com, which has links to it on the Hypex web pages. Some modules are OEM only, and not available on the DIY site, but third-party vendors seem to sell OEM modules to DIY enthusiasts All in all, a nice segment of today’s audio gear environment.
Tripath Technology was founded in 1995 by a Silicon Valley Ph D. electronics engineer, Adya Tripathi, who had previously held senior positions with AMD, HP and IBM. As far as I know, Tripath was the first company to offer true high-fidelity Class-D amplification, which they called "Class-T" and trademarked the term for marketing purposes.
The fact that Audio Research, Bel Canto, Sonos, Apple and other high-quality technology companies designed and sold Class-T amplifiers speaks to the role of Dr. Tripathi’s technology in moving Class-D up into the realm of high-fidelity, in spite of its inherent flaws and artifacts. The continuing popularity of the remaining NOS Class-T chips and modules 13 years after the company went bankrupt is testament to the quality and performance of the development of that technology. Unfortunately, when the big semiconductor companies like TI moved into Class-D chips for mass-market A/V electronics in a big way, it killed Tripath and Class-T. All that remains is lots of inventory. (Three years after Tripath went belly-up, Dr. Tripathi founded another Silicon Valley tech company, "Tula Technologies" that is also into saving energy. Rather than audio, Tula's software products are DSP for ICE (internal combustion engines), including a pairing of digital signal processing and sophisticated powertrain controls. This technology can enable the removal of 1 ton of CO2 per vehicle per year and boost MPG by 7-15%.)
Although there are many poor implementations of Class-T amplification as well as some excellent ones, I am not aware of a “bad” Hypex amp - the surviving notable Class-D amplifier manufacturer. Hypex Electronics is a Dutch company that was founded in 1996 to make plate amplifiers for "live sound loudspeakers." In 2003, Hypex executives recognized the movement of Class-D technology towards market dominance, so they developed their proprietary “Universal Class-D” variant and called it “UcD.” Just like Tripath’s Class-T technology, UcD lives on more than a decade later, but unlike Tripath, Hypex is still in business. Then NcD line was joined in 2008 by a newer variant, the Ncore series of modules, which add a high-quality switching power supply to the module. UcD amps with switching power supplies, and Ncore amps with on-board power supplies are much lighter than many “audiophile” UcD-based amps with heavy iron-core linear power supply transformer(s) present. (Of course, some people prefer linear power supplies, and I am guessing that Hypex will continue to manufacture both both UcD and Ncore products.)
So, while Tripath tried to compete in the mass market electronics sector, Hypex appears to be focusing on high fidelity and smaller specialty markets - audio enthusiasts/audiophiles, DIY, and pro audio – and they are apparently succeeding. They actually have two marketing/sales divisions – OEM and DIY. OEM is factory direct, and DIY is via DIYClassD.com, which has links to it on the Hypex web pages. Some modules are OEM only, and not available on the DIY site, but third-party vendors seem to sell OEM modules to DIY enthusiasts All in all, a nice segment of today’s audio gear environment.
