Symmetric Amplification

Class A amplifier? As a side benefit, you can fry your breakfast on it.

On a related note, I recently tried powering a front end with asymmetric supplies (+4V and -6V instead of +/-5V) to see if biasing the amplifier's input stage a little off the 0V rail would reduce crossover distortion. I tried this with two high spec JFET input op amps (ADA4817-1 and AD86something) with a gain of about 1 million in that stage. I could see no performance improvement. I concluded that modern op amps are so good that input stage distortion is negligible.

Nemo

Indeed... we are all twisted in our own personal way ;-) ...Jim Thompson

Speak for yourself.. ;)

Jamie

The path travelled by light in a vacuum without gravity - i.e. 99% of what we call "space"

The edges of crystals come awfully close.

John

Bob Newhart was pretty good at delivering them.

How about a still spider hanging on its strand of silk? The silk will be pretty darned straight.

John

Gravity is not everywhere - it is only where mass is. Hence light is straight unless to insist on measuring it near planets and stars (etc)

Get real. There are gravitational forces _everywhere_. So there are NO absolutely straight lines... except in Larkin-land... and that's because of the fairies ;-) ...Jim Thompson

Symmetric in the local vicinity of an operating point is the best you can expect to find in semiconductor devices. There ARE some vacuum tubes that use beam-steering onto split anodes, and THOSE are as symmetric as the left and right halves of the fabricated elements.

Why ever would a symmetrized gain cell NOT be what you want?

Well, if you allow magnetic field as the input channel instead of 'voltage', a Hall sensor qualifies. It's not generally considered a useful amplifier, though.

Incandescent vactrol.

John

He *is* being real. Light travels in straight lines to an incredibly good approximation as soon as you are more than a few diameters away from a normal matter or plasma based gravitating object. If it didn't we would see the sky altering and being distorted around the moon.

Most of the universe is empty space so a ray leaving the any star will travel in a straight line by default unless it passes really quite close to or through a strong gravitational potential well.

The effect that Eddington measured at the total solar eclipse for stars with light passing extremely close to the sun was barely measurable at under 2" arc as predicted by Einstein against a reference plate taken six months later. The deviations from a straight line are tiny even for stellar mass objects at grazing incidence.

So whilst you could argue that light doesn't travel in *perfectly* straight lines (to be accurate it travels along the null-geodesics or in classical terms along the path of minimal time) they are the closest we get to straight lines in the universe and span huge chunks of it.

The effects of objects in the way can be rather pretty through the influence of galactic clusters on even more distant objects.

Regards, Martin Brown