Fresh From the Bench: A Tale of Two Class-D Amplifiers Orchard Audio Starkrimson and Purifi Audio Eigentakt EVAL1

Stuart Yaniger examines new amplifier solutions from two disrupting audio companies. Purifi Audio from Denmark, founded by Bruno Putzeys, Lars Risbo, and Peter Lyngdorf, together with a remarkable engineering team; and Orchard Audio, with a product developed from the creativity and entrepreneurship of Leonid (Leo) Ayzenshtat, in this case exploring the latest gallium nitride (GaN) semiconductor technology. This article was originally published in audioXpress, July 2020.

Following the immensely popular and retro styled MA252 and MA352 Integrated Amplifiers, which took design cues from the timeless MC275 Vacuum Tube Amplifier, McIntosh introduced two more matching separates with similar styling: the MC830 Solid State Amplifier and C8 Vacuum Tube Preamplifier. "Featuring styling reminiscent of their 1950s and 1960s designs, the MC830 and C8 are full of modern day technology to produce an amazing home audio experience. When a pair of MC830s are combined with the C8, they can form the foundation of system that can deliver a lifelike home audio experience," McIntosh says.

For those audio enthusiasts considering their options to acquire a new amplifier that uses Purifi Eigentakt amplification technology, NAD Electronics announced another high-performance, affordable and very attractive option. The C 298 is a two-channel design that is a perfect partner to high quality preamplifiers or in any application where additional channels of high end audio amplification are desired. This new NAD classic amp boasts 185 Watts per channel into 8 Ohms and can be bridged to 620W X 1 into 8 Ohms to create a huge Monoblock.

In this article, Stuart Yaniger reviews the M10 Masters Series Streaming Amplifier from NAD Electronics, a compact but powerful Class-D home audio amplifier and network streamer that surprises positively for multiple reasons. One of those is the integration of the latest Dirac Live room correction technology with Bass Control, which is also covered in detail in this review. The other is the number of versatile features that make it the only item needed for a modern music system, other than speakers. This article was originally published in audioXpress, August 2020.

Our late and much esteemed author, Ron Tipton, shared a fascinating project on testing Class-T or Tripath power amplifiers on the pages of audioXpress. As he characterized, these "small, inexpensive, and power-efficient units," sounded good "but testing them is problematic." The article also discusses the story of Tripath Technology and speculates on the reasons why the Tripath ICs remained popular among the DIY audio community. This article was originally published in audioXpress, March 2014.

Following a preview at CES 2020, the highly anticipated amplifier of the year 2020 by NAD Electronics - the first company to license Purifi Audio's amplifier technology - is now shipping! NAD M33 is the latest BluOS enabled DAC/amplifier that can serve as the heart of a reference whole-home system. In its simplest form, the M33 ($4999 U.S. MSRP) is an ultra-high-performance streaming amplifier with superb sound. And it can obviously be combined with a BluOS ecosystem of wirelessly networked music players, creating a whole-home audio system.

From audio development and product design to acoustics! Read the Acoustic Solutions Round-Up and expert articles. Check out the NAD M10 Masters Series Streaming Amplifier review, then learn about Sound Liaison, a recording label translating live acoustical recordings in the best possible quality. Jan Didden reflects on "The Internal Life of Vacuum Tubes," and George Ntanavaras introduces his APR-17 Aperiodic Loudspeaker design. audioXpress August 2020, Focus on Acoustics, is now available in print and digital.

audioXpress July 2020 is now available, and there's a quiet revolution happening in audio amplification. Essentially it is the direct result of strong innovation in Class-D technology, with incremental improvements introduced on multiple fronts. In this month's Market Update, J. Martins details a few of the "Class-D Products Getting Smarter" and then Stuart Yaniger discusses Class-D amplifiers from two of those companies: Purifi Audio and Orchard Audio. Also, Ward Maas details his visit to Purifi Audio. Dimitri Danyuk shares his "Fully Balanced Transconductance Preamplifier" project, Roger Russell is "Hunting the Elusive Transient," and Ed Simon concludes his "Powering Your Circuits" series. And there's much more valuable content in this edition. Download or view your issue online now.

Parasound has introduced a 12-channel, 2-ohm stable power amplifier for commercial and residential audio systems installers with flexible power options for stereo audio in six rooms (zones), and up to 24 individual speakers. Uniquely, the Parasound ZoneMaster ZM 12 drives two channels at 120 watts each, 8 ohms, with the remaining 10 channels at 60 watts each. With 4-ohm speakers typical of architectural audio, the ratings are 150 and 100 watts respectively. There are also A and B speaker outputs for each channel. With this upgraded performance and features, the ZM 12 represents a significant advance over its 12 x 50W predecessor, the ZM 1250.

Purifi Audio, the Danish company founded by Bruno Putzeys, Lars Risbo, and Peter Lyngdorf together with a remarkable engineering team, promises Class D amplifiers with record-breaking performance (as well as speakers). Now, Bruno Putzeys made available a detailed report of his investigation on hysteresis distortion, which motivated the development of the company's products. As Putzeys describes, hysteresis in the ferromagnetic material of the amplifier output filter coil is what causes "a recognizable grainy texture in the sound."