Are future improvements in Amp/PreAmps slowing to a crawl?

Speaking of Pass, it is important to note that the model for a high quality SS amplifier was first really codified in the late 1970's by the work of the late Dr. Marshall Leach Jr. Using bipolar transistors Dr. Leach's proposal set the blueprint for every SS design going forward for decades.

Almost 40 years after this paper, I would love to have a panel discussion with Pass, Curl, Carver about how far we have come from then, what Leach got right, what he got wrong, or what they think Dr. Leach would have done better with the parts we have today.

Best,


E

Anyone who thinks the best Class D is the lesser technology or always inferior sounding when compared to Class A is just not paying attention.

"Will it sound like what you like?",

That is a completely different discussion to have. If anyone can make a _better_ amplifier than the best linear and Class D for normal speakers I cannot hear it.

However, lots of ways of making amplifiers sound different, juicier and more colorful.

As someone once told John Coltrane (I believe): "You can't make it better, only different."


Peace,

E

Want to give a shout out to Carver, the concept for his magnetic field amplifier continues to be used by Yamaha, NuForce and possibly even NAD (D 3020).

Carver's design used a linear amplifier of relatively small power handling and hooked it up to a power supply of varying rail voltages. This minimized the power dissipation required in the output stage. Carver sued (and won) against Yamaha, but the Yamaha Pro line is using the EEEngine which seems derived. NuForce is using the idea in their hybrid amps, Class-D providing the voltage rails, with a linear amp sandwich, and maybe... the NAD D 3020.

Still, how old is this tech? We can definitely argue against calling it all that revolutionary.

Is any of it better sounding? Not sure, but Yamaha and Nuforce are free to send me samples.... :)

Best,


E

@dlcockrum

Yeah, you are not the only one! Apparently Carver did not have any PC's to do Monte Carlo simulations. It took him years to figure out the problems, AFAIK, related to switching voltages far too fast in the power supply, causing dead shorts.

Best,

E

I never said the amps were exceptional, but that the paper put together the formula.

I am unaware of any other document before his paper that put together all the components that would become known as the SS formula. If there are, please share.

High distortion SS amps were no longer passable as hi-fi.

I have no idea what "frequency overload" means. Explain?

Nice find, Dave!

I wonder if we'll see that circuit in a headphone amp? :)

Best,

E