Peter Perreaux...original designer of the 1970's-80's amps and preamps. I had an Acoustat TNT that was powering my Acoustat 2+2's.The TNT was stolen (don't ask!), so I went to my dealer to replace it. He demo-ed a CD with loud transients and the TNT clipped his 2+2's at a moderately high listening level. He then hooked up a Perreaux PMF1850 to the Acoustats, played the CD louder and the amp sailed right through it. I bought it and used it on my 2+2's for over 15 years.
Dale Pitcher, formerly of Essence and now of Intuitive Design. The first time I heard Essence SS amps I immediately sold all my tube and other SS amps and quit looking for the holy grail of audio. His carbon nanotube cables were recently reviewed here on Audiogon, and his speakers have won several Best in Show awards.
Dave Gore for the Quatre Gain Cell amplifier.
When The Audio Critic's first issue came out - they had a amplifier show down.
Yamaha B2 V-Fet amp, Audio Research, Threshold, and others. The Gain Cell was their choice over the others. So Mr. Gore definitely deserves a place in this pantheon. (to this day that amp was one of the greatest bass amp I've ever heard. Liquid sounding and dynamic)
Andy Hefley designed the GAS Son of Ampzilla and Thoebe preamp after Jim Bongiorno left to start Sumo. This amp/preamp combination is still a formidable contender against today's multi-kilobuck gear! I am at this moment using this combination with a pair of DCM TW's (52779, 52780). Truly excellent sound!
If you really want to learn about great amps, I highly recommend researching and building one. Watch the Burning Amp lectures. Read Nelson Pass's wealth of articles. I'm anything but an electronics engineer, but my understanding of amps has come light-years in the course of researching, building, and troubleshooting a Pass amp. Pass has dozens of designs that he's written articles on and explains well. Bob Cordell explains some older circuits well too.
If you want to talk SS amplifier designs, I strongly suggest you look into the late Dr. Marshal Leach Jr.
His 1976 paper, "Build a low TIM Amplifier" codified the modern SS amplifier and set the standard for designs for years to come.
I write a little about him on my blog, here:
Bruno Putzeys. "With the invention of UcD and Ncore, Bruno Putzeys is probably single-handedly responsible for turning class-D amplification into the preferred way of building high-end audio amplifiers. His designs are displacing class A and valve amplifiers in all the niches they held until now and are making truly audiophile performance available in very compact, energy-efficient products.
Putzeys is one of the world's top designers of a type of audio amplifier known as class-D. These ultraefficient models are already dominant in multichannel sound systems, portable media players, cellphones, car stereos, and computers. Lately they have made inroads into the ostentatious world of high-end audio, where a component can cost tens of thousands of dollars. Their success there is due mostly to Putzeys.
In 2001, while working at Philips Applied Technologies in Leuven, Belgium, Putzeys designed a compact, versatile class-D amplifier module that he called UcD, for ”Universal class-D.” Over the past few years, dozens of amplifier models, with prices ranging from US $500 to $8,500, have been built around Putzeys's modules, which are now manufactured by Hypex Electronics of Groningen, Netherlands. The amps have received mostly ecstatic reviews.
For Putzeys, the success of the UcD boards has conferred professional freedom that's pretty rare for a 34-year-old EE. In May 2005, he followed his modules to Hypex, where he is now the chief tech guru".
Please see Hypex Electronics and Mola Mola Audio Products.
What a sales pitch!
I think it's pretty bold to say that class D is displacing class A amps though, which they really aren't. They're starting to put a dent in mid-range class AB and that's about it. I don't think the folks at Boulder, Pass, and D'Agostina are losing sleep or faith in class A.
Beyond all that, are there more complicated amplifier designs on the whole planet? And who exactly has called a class D amp "the best"? The highest compliment that's ever been paid to a class D amp is that it sounds as good as a class AB amp. Digging into class D amps is hardly a lesson in legendary amplifiers.
Tim Isaacs is a respected name in the U.K. with regard to amplifier designs in the 70's and 80's. He designed a MOSFET output stage amp that played like Class A at lower power but slid into AB Mode at highest power - best of both worlds - high power when needed but low distortion and low heat output...