Tag Archives: tube

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.

Yes, they do!!

Parts matter

Of all the things we do at PS Audio, perhaps what drives some people crazy more than anything is our insistence that parts matter to sound quality.

No one would argue that the difference between a precision value resistor or a matched vacuum tube or transistor in a critical area isn’t important. We can easily measure the differences in performance. But what of the various types of capacitor or resistor construction? For caps, there are ceramic, electrolytic, tantalum, film and foil, metalized film, dozens of different dielectric materials, and multiple conductor types to name just a few. And choices of resistors are perhaps just as dizzying.

Most measure identically in a circuit, yet sound remarkably different.

In mass-market consumer audio, where price is the point and performance is judged by meters and marketing people rather than experienced listeners, the many choices of parts quality are a Godsend for keeping prices in check.

High-end audio’s quite another thing altogether. Brands that place performance first and price second, use any and all available choices to get what they want out of a design.

Parts matter, but in different ways to different designers.

 

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.

List of ingredients

Prepackaged foods list their ingredients so consumers know what they’re putting into their bodies.

My rule of thumb is not to eat anything I cannot pronounce or if the list sounds more like a Gilbert Chemistry set than food.

Stereo equipment manufacturers have no such rules though many tout the good stuff (and generally keep quiet about the ho-hum parts).

The more organic the parts the more likely a manufacturer is to list their ingredients: vacuum tubes, film capacitors, MOSFETS, JFETS, GaN FETs, FPGAs, precious metal connectors, high purity wires.

Other than food, automobiles, furniture, clothing, and high-end stereo equipment I can’t think of many other products that care to list their primary ingredients. Perhaps this is because consumers don’t care?

More likely it’s because it’s not important. I don’t really care what this computer is made of nor do I give a rat’s ass what type of rubber or plastic goes into the tires on my car.

I do care what the ingredients are in my speakers and electronics because I believe their composition plays a major role in the quality of music I am expecting to enjoy.

Not every FET, tube, or carbon fiber cone sounds best but it certainly is a good starting point from which to form an opinion.

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.

Wildcards and curveballs

Sometimes everything goes according to Hoyle. But, more often than not, a wildcard gets slipped in—a fact not listed in Hoyle’s Games—but true none the less. Most people around the country can put their trash in the outdoor receptacle without a second thought but not residents of our neighborhood. Hungry bears.

When we get a new piece of stereo equipment our expectations are high for drop-in-and-work and often that’s exactly the case. But then, there’s that curveball: the need for a better audio cable, different position, realignment, or tube swap.

I used to get frustrated with wildcards and curveballs but over the years I have begun to understand their value. By introducing unexpected variables I am required to step outside my comfort zone and learn something new or look at a situation from another angle.

Learning expands horizons. The farther I can see the greater my wealth of possibilities.

I don’t go looking for unexpected circumstances but wildcards and curveballs are some of the best uninvited teachers I know of.

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.

Right tool, right job

You can make almost anything work. Getting things to work right is a bigger challenge.

Take for example a Power Plant AC regenerator. We’d love to use Class D amplifier technology for the output but have consistently stayed with good old Class A/B. Right tool, right job.

Class D amplifiers can be terrific for the reproduction of music and so too can Class A/B. The reason either can work for music but only one for a regenerator is because the jobs are different: powering loudspeakers isn’t as extreme as powering equipment.

Speakers might demand instantaneous current approaching 10 amps for short periods of time—a workable challenge for both amp topologies. Equipment and AC power routinely demand 50 to 60 amps for a regenerator—at 5 times the voltage presented to a speaker. That’s a job for an amplifier without a heavy output filter.

In the same vein, using a vacuum tube for the input rather than the output, or a DC servo instead of a blocking capacitor, is the essence of using the right tool for the right job.

Hard to know what’s right and what’s wrong if you’re not a designer yourself. Which is why it’s important to find a company or a designer you can trust.

Right tool, right job offers the best performance.

 

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.

Devils and details

Part of the challenge in audio engineering is to know when to use certain processes or devices and when to use others. For example, a tube in the input stage works well, but not so much in the output. Or, a capacitor used as a DC blocker might sound better than the complexity of a servo, or, vice versa.

Analog integrated circuits, like op amps, can typically be bettered by their discrete counterparts in some cases, but not all. For example, if component matching is a critical aspect to your design then there’s likely no better process than integrating everything on a single piece of silicone. Each component tracks the temperature variations of the other for near-perfect matching.

Yet, in the same way separates can outperform integrated amplifiers, there are disadvantages to IC solutions too. The limitations of single silicone, including low power requirements and a lack of isolation between components, can hinder performance levels in highly resolving systems like the kind you and I might want at home.

It’s always a good idea to keep sweeping proclamations of better and worse at a minimum.

Like just about everything else in life, it’s the details that flush out the devil.

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.

PS Audio has announced the availability of their newest and most advanced AC power re-generator, called the P 20, for high end audio systems.  What a piece of  audio equipment!

I wish I could both afford this and had space for it, as its expensive, big and heavy.  However, with one kid in college and another getting married this fall, it will have to wait. Besides, the Furman IT Ref20 I am using, which is a big, balanced power, isolation transformer, works pretty darn good and at 85 lbs, I’m not so interested in moving it. If I didn’t live out in the country and had friends closer to help me move stuff, maybe, just maybe, Id be tempted, as this piece from PS Audio is the absolute state of the art in feeding our audio systems perfect power.

Rabbit holes

The problem with rabbit holes is they are easy to go deep before you realize it’s the wrong one. I went down several in the design of the amplifier line that eventually became the BHK, as well as building the first Power Plant two decades ago.

My first idea to design a perfect AC power generator was a carbon copy of what powers our cities. A spinning, mechanical, power generator. Mine would not be spun by the fires of coal or natural gas, but instead by the very power I wanted to replace. On paper, I built an electric motor coupled to a generator like you might have on your bicycle. From it would come perfect, clean, low distortion sine waves regardless of the power quality coming in.

That rabbit hole venture was quickly abandoned as Terri told me there’s no way she’d allow a spinning noisy mechanical generator anywhere near the inside of our home. I suspected others would feel the same way.

My second rabbit hole got me closer. A tube-based HP sinewave generator connected to a stereo power amplifier. Though kludgy and impractical, it worked and proved my idea that the best AC power in the world had to be generated. Nothing else would do. Certainly not a simple power conditioner, which seemed to me at the time about as useful as the polishing of a turd. Brighter and shiner but it still stinks.

Today we officially launch the DirectStream P20, our finest expression of the art of regenerating new, perfect AC.

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.

When hard sounds easy

I was marveling at the skill of my tongue. It rarely gets in the way, it hardly ever gets tied, and it nicely punctuates speech without a great deal of effort. In fact, I never think about it at all, which is all the more amazing given its critical role.

I often think of weird things.

Thoughts of underlying hard things that make life easy leads me inevitably to the art of reproducing music. Think of all the thousands upon thousands of brilliant minds, inventions, breakthroughs, miracles, brain scratchings, and just plain hard work that went into any part of your stereo system. Even something as simple as the turntable/arm/cartridge has consumed multiple lives of brilliant innovators to get where it is: Joe Grado, Ivor Tiefenbrun, Garrard, Sidney Shure, Arnold Poulsen, Axel Petersen, Harry Weisfeld. Hell, might as well throw in Thomas Edison while we’re at it.

And a turntable, arm, and  phono cartridge are relatively simply electromechanical devices. Imagine what it took to invent the vacuum tube, transistor, or a CD player.

What you and I have in our possessions are miracles unimaginable just a century ago. We’re moving quickly, and we have much to be thankful for. Music at the touch of a button streamed from anywhere in the world, from any composer or artist. Most of the major recorded works available in our homes with a glass of red wine and a bite of cheese by our side.

When our impossible technologies seem easy. These are wonderful times, indeed.

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.

I built the speakers I am currently using, but had some help. The manufacturer of the driver, Great Plains Audio, also designed the crossover, although we replaced many of the parts inside. I designed the cabinet and the matching external crossover boxes and had a local guy build them, which was a interesting experience.

After some angst, the project ended up turning out beautifully and I’m very happy with the audio system, although I will be adding Rogue Audio’s new RP-7 tube preamp this week to continue to support my vendors, where it makes sense. What little high end audio I sell here, is Rogue Audio gear, so I am happy to support them. Great products, great people and everything is made in the USA.

I imagine it will sound at least as good as what I am using now, if not even better. I know ergonomically, it will work better and it has a tube headphone inside, too.

DIY speakers

How hard can it be to build your own speakers? Heck, the speaker drivers themselves are easy enough to get—Parts Express has just about every cool driver, crossover, and enclosure you might want. Many are identical to what’s found in the most expensive products in the world.

Pick the best you can afford, solder them up, and kick back to great sound. Right? Maybe, but more than likely not.

While we understand drivers, crossovers, and enclosures are about all that’s in the speakers we really love, the true skill in building world-class speakers isn’t exclusive to the parts. Without benefit of a capable designer, you often wind up disappointed.

If I had two bags of parts in my hand, one with all the necessary components for a speaker, the other to build a DAC, you’d likely have a better chance with the first than the second. Still, getting great sounding music out of a wooden box with speaker drivers, coils, capacitors, and binding posts is nothing too trivial. Many designers invest a lifetime of experience into making loudspeakers that honor the music.

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.

Can you make something better than it is?

To enhance something means to intensify—exceed what we might find in a natural state. Which raises an interesting question. Is it actually better or merely different?

Let us be clear. Enhancement is qualitatively different than what we generally look for in equipment: moving closer to purity. Lower noise, better linearity, are all moves toward purity that do not claim to enhance. Instead, they do less harm.

Changing a digital audio cable to a lower noise version would qualify as a move towards greater purity. Its bettered performance is a result of inflicting less damage.

A tube buffer would qualify as an enhancement since it is additive. (Despite your possible opinion that it is merely colored).

One big question in this same vein concerns preamplifiers. Do they enhance or purify?

We know that inserting a certain quality of preamplifier between the DAC and amplifier improves performance. But why? Is it an enhancement or is it doing less harm?

Over the years I have come to the conclusion it is doing less harm—isolating the digital side of things from the power amplifier’s analog purity.

But, I remain open to further learning on the subject.

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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