PS AUDIO: Truth or preference?

In our search for sonic truth, there comes a point where the systems get so good their “truth” is more about our personal preference. In fact, personal preferences often trump truth. We know we’ve gotten closer to the truth when it matches what we believe to be the musical truth. Of course, no one knows what musical truth is. […]

Read More

PS AUDIO: The additional linear region of a tube is wasted once you pass over a certain level. Wasted, that is, on linear performance – but valuable on another front – headroom in an amp

 Most tube power amps have an advantage over most solid state amps: high voltage.  If we look at a typical tube vs. solid state design, that tube design might have up to ten times more voltage than the solid state design – at least in a preamplifier.  The tubes need the high voltage to operate […]

Read More

PS AUDIO: “…… but, as always with any new fangled connection scheme, there’s a whole bunch of “gottcha’s” to go along with it.”

This’ll be the first of a few posts where we delve into networking and computer audio systems.  In prior posts we looked at what I would refer to as a closed system: a single computer with a DAC attached to it.  This works fine but has a number of drawbacks, many of which are not […]

Read More

PS AUDIO: Good stories are worth repeating; and I think this one qualifies in light of our most recent posts on the oil of snakes and cables

Paul McGowan writes: The summer of 1977 found my partner Stan and I looking to increase our sales of phono stages and we thought we would try and entice a few dealers to carry the product.  Up until this day we were 100% direct-to-customer, something you see more of today in high-end audio, but back […]

Read More

PS AUDIO: Sample rates

Paul McGowan writes … There sure is a lot of confusion over sample rates. We hear about CD-quality sample rates at 44.1kHz (and its multiples), or another common sample rate, 48kHz (and its multiples), and then there are multiple higher sample rates (176kHz, 192kHz as examples) and of course DSD. Lots of numbers. All very […]

Read More

PSA: Distance affirmation

Paul McGowan: One of the more satisfying affirmations happens when two or more unrelated people make the same sonic observation. We send out an update and emailed observations roll in. “What happened to the bottom end?” Or, “The top end just opened up.” For better or for worse, it is fascinating that so many unrelated […]

Read More

PS AUDIO: How does one measure the differences between amplifiers when they clearly sound different?

How does one measure the differences between amplifiers when they clearly sound different? The first and simplest measurements are frequency response and noise levels: frequency response shows us that everything we put in makes it through to the output and noise levels are an obvious thing to measure so we don’t have hiss. Fancier measurements […]

Read More

PS AUDIO: The significance of the folding transmission line in a loudspeaker?

What is the significance of the folding transmission line in a loudspeaker? My guess is that not many of you have heard of a folding transmission line in a loudspeaker, much less ever heard one working.  The late Bud Fried, from Fried Audio (pronounced “freed” as opposed to what one might do with eggs), was […]

Read More

PS AUDIO: Tailoring the sound

Paul McGowan … TAS reviewer Michael Fremer has an extraordinary music system—the best vinyl setup I’ve ever heard. And it makes sense that he does. Mike’s spent a lifetime learning about vinyl audio reproduction and hand selected the best equipment in the world. His digital setup played through that same setup doesn’t quite match my […]

Read More

PS AUDIO: Image size

Paul McGowan … All stereo systems produce a sonic image—some better than others. But, regardless of the image quality, there’s one thing we can say they have in common: a size to that image. If you turn the level of the stereo down to a whisper there’s a tiny image trapped between the speakers. Crank […]

Read More

PS AUDIO: Why flat?

When we look at the specs for a piece of audio equipment we want to make sure it doesn’t emphasize or reduce one frequency area over another.  We routinely see flatness specs that are within 1/10th of a dB from below where we can hear to way above where we hear.  These specs make us […]

Read More

PS AUDIO: Class is now in session

Paul McGowan … Sorry about the headline, just couldn’t resist.  We are going to start delving into the working of Class D amps, also incorrectly known as “digital amps” and correctly labeled PWM amps – short for Pulse Width Modulation. As is our custom we’ll start with an overview and then get into details. It’s […]

Read More

PS AUDIO: Surround ambience

Paul McGowan …. My friend, Sandy, is having good success adding a layer of ambience with a rear-positioned second set of speakers fed from an old Audio Research SDP1. You can read the late J. Gordon Holt’s evaluation of it here. Essentially, the device extracts the difference between the left and right channels, adds a bit […]

Read More

PS AUDIO: Global feedback

When we speak of global feedback we’re referring to the practice of wrapping the output signal of a device back to its input for comparison and correction. Because the input “knows” what’s right, a simple comparison circuit between the two serves to rectify any differences. Of course, nothing in engineering is a free lunch. You […]

Read More

PS AUDIO: Intermodulation

When we think about distortion products we are generally referring to the harmonic kind. Harmonics are naturally occurring byproducts of sound: a plucked string will generate the intended frequency (called the first harmonic) and then higher versions of that note, each slightly less loud than its predecessor. These higher frequencies are all integers (whole numbers) […]

Read More

PS AUDIO: Ignorance and confidence

When we set our sights far in the future the world looks nice and rosy. Imagine that new pair of speakers gracing your living room, the new amplifier, the rebuilt room. According to Mark Twain imagining the future takes a combination of things. “Kindness is the language which the deaf can hear and the blind […]

Read More

PS AUDIO: High voltage and linearity

In a recent post we covered the fundamental differences between tubes and transistors and one of those we’re interested in is linearity. Tubes and transistors are only partially linear devices – which means they will not always faithfully reproduce a larger version of the input signal on their outputs. In our example yesterday we placed […]

Read More