CA: What are your strongest areas of product placement? Auto-sound products, home theater pieces, DSL infrastructure, cell phone development? Which of these do you consider to be the most fertile ground for Class-T® technology? Are there other areas that you plan to explore?

Tripath: Tripath is involved with a wide range of research and development activities, however on a product level we concentrate on just a few key markets.

Tripath supplies amplifiers for flat-panel televisions to Samsung, Hitachi, TCL, and Eizo.

We are the market leader for high-efficiency amplifiers for Plasma and LCD TV's. Class-T® amplifiers offer the ability to pack high-quality audio into the small space around the panel. We expect this market to continue to grow quickly as the panel prices drop.

Home Theater amplifiers are another natural fit for Class-T®, as the market demands more channels, more features, and smaller form factors. The size of a good A/V System has dropped drastically in the past 3 years and they've added 2 channels [from 5.1 to 7.1]! So it's very important to avoid heat issues without giving up fidelity, and that's just what Class-T® is good at.

Recently we have been pushing into the automotive market, and that will continue to be an area of focus. As I mentioned, we have a few new products coming for that market, and I think we can make quite a splash.

Tripath also has a separate group focusing on the DSL line-card business. This is an application where our expertise in high-efficiency amplifiers allowed us to tailor one of our audio products for something unexpected and it has worked out well. We will continue to develop those markets, but separate from the core audio business. We are also continuing to invest in long-term R&D for new applications and improvements to our current technology.

CA: Are there any downsides to Class-T® amplifiers, either in terms of sound quality, pricing, or usability?

Tripath: I'd love to say there were no limitations, but everything has its cost. The great thing for the audio market is that Class-T® doesn't sacrifice sound quality. Currently several very high-end audio manufacturers use Class-T® in their products. Obviously, companies like Audio Research and Bel Canto don't compromise on sound. Traditional Class-D designs do pay a large price in sound quality, but as I mentioned before, Class-T® avoids those pitfalls.

Bel Canto's EVo Series amplifiers utilize Tripath's Class-T® technology.

In general, Class-T® is cost-competitive with most higher power solutions. Units with less then 35 watts and no restrictions on space or heat can probably be done cheaper with an AB amplifier. Most of those applications aren't concerned with sound quality, however. They're all about saving every penny. Our new line of amplifiers for the Home A/V market should make Class-T® very competitive for those markets.

There are some usability issues with switching amplifiers that are still being ironed-out. The big one is EMI interference [electromagnetic interference]. Simply put, the switching in the amplifier can interfere with a radio tuner (AM is particularly susceptible). Our line of automotive products has a method to avoid this problem, but it does cost some of the output power while listening to AM radio. We feel it's the best solution currently available and we're always working on improving it.

Digital Amplifier Revolution: The future is bright
The market for Class D and Class-T® switching amplifiers is still relatively young and untapped, but the technology clearly holds major implications for consumer electronics. The Tempe, Arizona-based consumer electronics market research firm Forward Concepts completed a comprehensive market study in June 2004. Dr. Daniel Sweeney, the author of the report, concluded: "Class D amplification is emerging as a truly disruptive technology and one that may eventually replace linear amplifiers in most audio frequency applications." Tripath, with its high-fidelity Class-T® amps, is consistently being touted in the CE industry press as a "a company to watch with its unique product solution."

In fact, Tripath has already had considerable success marketing Class-T® to the consumer electronics industry. Back in 2002, Blaupunkt became the first car audio manufacturer to harness Class-T® technology, winning a prestigious CES 2002 Innovations Design and Engineering Showcase Award for their 7-channel OD7500 PA Series car amplifier. Panasonic introduced the first in-dash receiver utilizing Class-T® amplifiers this year, the MXE CQ-C9800U. Home audio manufacturers are also well aware of the size and efficiency advantages of Class-T® amplifiers. Tripath's customers include Denon, Hitachi, Motorola, Onkyo, Sanyo, Sampo, Sharp, Sony, and Toshiba. And in April, Tripath announced new design wins for flat-panel TVs from Samsung, TCL, and Eizo.

The key to Tripath's continued success is the advanced sound quality of the Class-T® design in comparison to Class D amplifiers. Judging by the reaction of CrutchfieldAdvisor's resident rock star/car audio reviewer extraordinaire, Charlie Pastorfield, I'd say the future is looking very bright. Pastorfield summed up his appreciation of the Class-T®'s performance in the Panasonic MXE CQ-C9800U like this:

"After a couple of hours of listening, I became a Performance Digital believer. The stereo spread was noticeably more pronounced, and I kept hearing little details popping out (reverb on a snare drum, vocalist's lips smacking, amplifier buzz) that I wasn't accustomed to hearing, making the recordings seem more lifelike. And it wasn't that the mix was being reproduced inaccurately by the Tripath amplifier. On the contrary, I was hearing all the information on the CD reproduced pretty damn close to perfection, just like you'd hear on a high-dollar home stereo system.

My thanks to Shawn Scarlett of Tripath Technologies for his help with this article.