Tag Archives: amp

Asheville, Walnut Cove, Biltmore Forrest and Western North Carolina’s Audio and Home Theater specialists present Cane Creek AV and Paul McGowan of PS Audio

Paul is getting technical here, but what he is beginning to describe today  are different ways to make an amplifier make music through speakers via solid state amplifiers, as opposed to tube amplifiers, although tube amps also have different ways to operate. Today, he describes something called a Class B circuit, which nobody I know uses exclusively. Class A/B yes, but Class B, on its own, no.

There are no hard or fast rules as to which type of amplifier sounds best. So far, in my 35 years in this audio hobby, the best solid state amp I’ve heard is the one I’m using now, which is a class AB amp, but has a speaker compensation network built in, which take most of the speaker cables out of the sound equation. Unfortunately, it is a Pro amp, built in the early 80’s, has fans, albeit quiet enough to not bother me…much….. and is pretty ugly. Still, it sounds great.

I’ve had Class A amps, Class A/B, Class H and Class D amps and sound wise, they are all over the place. I’ve recently taken in a pair of  Class A Aragon Palladium II monoblock amplifiers on consignment and they sound pretty darn good,

Here is Paul.

How much is enough?

We’re familiar with the common terms describing amplifier bias levels: class A, AB, and B. And we generally want more bias for better sound—which means we like class A better than the lower bias settings of AB and B. But how many of us really know what all this means? How much is enough?

Let’s start at the beginning to help our understanding.

First things first. These classes of amplifiers generally apply only to solid state designs. With few exceptions, we don’t worry about tube amplifiers and their output bias schemes. For simplicity sake let us just avoid the subject of tubes and agree that when we refer to the classes of an amplifier we are talking solid state.

Modern solid state power amplifiers split the output signal in two—one for the top half, the other for the bottom. Here’s a picture.

The two bluish circles labeled NPN and PNP are the transistor output devices. The squiggly lines are resistors that you can ignore. Note how the top transistor (TR1) handles what’s labeled as the “positive half-cycle”, the bottom transistor the “negative half-cycle”.

The input signal in this illustration is a simple sine wave. The circuit breaks the sine wave apart and divides the reproduction duties between the two devices.

What you are looking at is a Class B circuit. No Class A’ness to it at all.

More tomorrow.

 

 

 

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Asheville, Walnut Cove, Biltmore Forrest and Western North Carolina’s Audio and Home Theater specialists present Cane Creek AV and Paul McGowan – PS Audio, Intl.

Ever wonder why sunrises and sunsets are more colorful than the sun is during the day? Here’s an explanation from Paul.
Does knowledge limit magic?

Enjoying a fresh cup of coffee this morning I am in awe at a most amazing sunrise. Reds and oranges color the eastern sky with a fluorescent palette—a work of art. But why? Why the color in the morning and not at noon?

Ordinary sunlight is composed of a spectrum of colors that range from violets and blues at one end to oranges and reds on the other. When light passes through air molecules it scatters. Because tiny air molecules are closer in size to the shorter wavelength of violet light than to that of red light, pure air scatters violet light three to four times more effectively than it does the longer wavelengths. At sunrise or sunset, the sun takes a much longer path through the atmosphere than during the middle part of the day, increasing the amount of violet and blue light being scattered out of the beam. The light reaching your eye early or late in the day is noticeably reddened.

That’s the knowledge base. And it is often thought that knowing these facts takes the magic out of the experience. Like a magician watching another practitioner of the art.

If you understand technology is there still magic? Arthur C. Clark wrote, “Any sufficiently advanced technology is indistinguishable from magic.”

That is certainly true, but then I struggle with the opposite.

I understand how an amp works, yet that knowledge doesn’t diminish the magic that comes through speakers.