There was also Dr. Tripathi's Class T amp for high efficiency speakers. Very low distortion, low noise, low cost and sound quality so good that the big chip brand who acquired the patent for the TA2020 chip deliberately killed it.

I built a Class H amplifier for use on 12volts ... it used a Philips IC with all the necessary circuits built in ... it sounded great ! It delivered 70 watts into 4 ohms

Another good one that has been on my mind recently as well! Thanks Paul!

Thank you great explanation. I have a Technics SA-DX940 Class H+. The question come up at work a week ago. Now I know.

OSD Nero amplifiers say they are a Class H design. They actually sound very good and run cool for a very reasonable price.

Here in philippines, class H power amplifiers are famous. They are used in big mobile sound systems and mini sound systems. Many manufacturers here makes class H power amp that can produce over 20,000 watts rms......

I have 4 RPA-16's from Rockville.. Class H amps.They are something else for the money! 47lbs. each.. They are BEASTS!

Many pro audio amplifiers have a class H topology. QSC is a prime example. Repairing them is a nightmare due to the multiple voltage rails available to the amplifier and the feedback circuit used to switch rails.

There is still a large market of Class H in the Philippines, there’s this event called Battle of the Sounds, hard-kick bass lovers.

Great analogies!!! Great vid Paul!, Thank you. Keep em coming.

Thanks. I learned something today!

Complimenti per il video, posseggo l'amplificatore Pioneer A-70 vintage anno 1983 dynamic power non switching in classe H , 2x120 watt rms su 8 ohm e 2x 320 watt rms su 4 ohm , ha un suono cristallino ,completo e con bassi potenti

Enlightening! thanks

Bob Carver used class H in his tfm line of amplifiers. I currently own an AV 705x 5 channel amplifier for home theater. I've had it since 2003, bought it used and it's a workhorse. 125 watts channel 5 channels driven. I can crank that bad boy all day and it only gets warm.

Well explained.

Soundcraftsmen baby!

The Benchmark AHB2 is class H.

Sorry Paul that's not right here are the definitions of class G and H . Class-G amplifiers (which use "rail switching" to decrease power consumption and increase efficiency) are more efficient than class-AB amplifiers. These amplifiers provide several power rails at different voltages and switch between them as the signal output approaches each level. Thus, the amplifier increases efficiency by reducing the wasted power at the output transistors. Class-G amplifiers are more efficient than class AB but less efficient when compared to class D, however, they do not have the electromagnetic interference effects of class D.

I'm a bit confused because if Class H has been supplanted by Class D, then why does the Benchmark AH2 100 watt per channel perform so superlatively in terms of measurements and sound quality? I haven't heard them myself, but it is frequently lauded as good or better than any high end amplifier. Also it seems that most high end and ultra high end amplifiers, I've looked into are still mostly Class AB.

Interesting, I can imagine a multi-taped power transformer generating several rails, however swapping from one to the next would be tricky, swapping cleanly between the two sides of a class AB, without generating crossover distortion is bad enough, but then stepping through many supply options for the output stage - wow.