Tag Archives: amplifiers

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

It’s not that simple

An isolation transformer cleans up noise on the AC line yet often harms system performance. How can it be true that an improvement over here impacts performance over there?

The simple answer is that the problem is not that simple. The cleanest power in the world only gets you so far.

This question of influencing performance can be a real head scratcher: we know that lower distortion is a good thing yet not all low distortion audio amplifiers sound good. We know that low output impedance is preferable yet at what cost?

Here’s the thing. As I mentioned in yesterday’s post about the Long Tail, as we get closer to perfection each link in our progress chain become more important. Where it used to be alright to swap a major piece of equipment in the chain without too much worry, now even the smallest bits have a great impact.

When we place an isolation transformer in the AC path we improve one area, cleanliness, by degrading another, regulation and impedance. An isolation transformer helps keep unwanted noise from the system at the cost of voltage regulation.

It turns out that voltage regulation is far more important than clean power. The greater the regulation the lower the impedance the better the sound quality.

An AC regenerator like our Power Plants provides the tightest regulation and highest current delivery of any power product on the market today. There are other technologies that might provide cleaner power, but none that focus more on what’s really important.

It’s just never quite that simple.

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.

Performance above 20kHz matters

Fact or fiction?

Does amplifier performance above 20kHz matter?

This question came first in our list of Fact or Fiction because it’s a fairly easy one to answer but the answer’s going to piss off a whole bunch of objectivists. Let’s try and fix that so everyone wins.

To an objectivist, 20kHz and above does not matter for one plain and simple reason: humans cannot hear above 20kHz. Ergo, if we cannot hear something then it doesn’t matter. Case closed.

While the base statement is accurate, it ignores the consequences of implementation.

If we instead look towards the practical application of high bandwidth amplifiers we see that we could ask a very different question and get a very different answer. The right question to be asking is this:

Does phase accuracy matter within the pass band of human hearing?

Now we have a proper question that circumvents all the narrow focus arguments that plague us.

The answer to question 2 is an unequivocal yes! Human hearing is very sensitive to phase differences within the audio pass band.

Circling back to the first question, we can now answer it with another unequivocal yes! because there are no practical means of bandwidth limiting an analog amplifier to 20kHz without affecting the phase. It’s typically important to have a bandwidth approaching 100kHz to get phase accurate performance in the audio pass band.

See? That wasn’t so hard.