Tag Archives: monoblock 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, Intl.

I’ve heard the PS Audio system at their previous location and very good, although that room was too small for the Infinity IRS V loudspeakers.


The three P20 Power Plants, two BHK monoblock amplifiers, 12 channels of 1,000 watt amplification, the Infinity IRSV and all the other peripherals to be found in Music Room Two form the basis of the PS Audio Reference System.

Is it the best system in the world? Of course not. There’s likely no single system that might qualify for that honor.

What we can say, however, is that it is a reference-quality system. And what does that actually mean?

In my view, a reference system has a number of requirements. It must be neutral, full range, highly resolving, unflappable, and most important, reliably utilize all its merits to test the identity, strength, quality, and purity of any connected gear. In other words, it cannot impart its identity on devices under test.

While constant improvements to the system are expected—even demanded—those improvements must always be made with the goal of neutrality without suffering sonic bias.

A true reference system is different than a maxed out home audio system. In the former, we want limitless unbiased resolving power where, in the latter, we accept bias in favor of knocking our socks off.

You probably don’t have a reference quality system at home, but in the long run, that’s likely a good thing.

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 swear music is addictive. If I go more than a few days without my dose I am unhappy. Jittery. Argumentative.

And music in the car, or what passes as background music in my home, soothes the withdrawal symptoms but does not give me the fix I need.

My true drug of choice is found in Music Room Two and the IRSV. I press the standby button on the BHK preamplifier. Ten seconds later there’s the satisfying click of the BHK Monoblock amplifiers turning on at the behest of the trigger voltage. Another 10 seconds later and my spirits rise as the IRS servo woofers thump into life. And then all is right. The air in the room feels different. Perhaps it’s the slight rush of noise from the servo woofers. Hard to say. Easy to feel.

I am listening to Gus Skinnas’ latest mix of Jessica Carson’s masterpieces. There’s that opening sound of the room just before she plays the first notes on the piano. Maybe its the air conditioning system in the studio, or the slight shuffling of her feet finding the piano pedals. I am transported into the music and we are one.

I don’t need more for a day or two before withdrawals set in and the pattern repeats.

My drug of choice.


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.

This is timely as I just had a 17 year old pair of Aragon Palladium II monoblock amplifiers re-biased after we discovered more reliable documentation regarding the proper bias settings. As the original  Aragon company was sold to Klipsch, which did nothing good with the  Aragon/Acurus product line, which often happens, and then sold by Klipsch to Indy Audio Labs, who continues to build products based on the original design, there was a scarcity of information regrading these particular amps.  After a little digging and confirmation from Indy Audio labs gave us the info that we needed, we re-biased and them amps definitely sound better. Run a bit warmer too!!

Thanks Indy Audio labs.

Tuning with current

When it comes to traditional class AB amplifiers there are two schools of thought about bias. Engineers can add enough class A current to satisfy their distortion analyzers or their ears. Most keep the analyzers happy without worrying about sound quality and it’s pretty easy to see why. Class A bias produces unwanted heat that is costly to dissipate.

Some degree of class A bias is required in a low distortion amplifier. It is bias that keeps the output devices from switching off and creating distortion. The minimum current needed to eliminate distortion isn’t much, but not all of us place economy above performance.

How an amplifier sounds—particularly in the areas of detail and low-level music—has a lot to do with its bias level. Typically more is better, but only to a point. Successful high-performance designs balance higher output current with available power supply and design goals so as not to cross the line of excess. Too much bias can actually weaken the slam and bass grunt of an amplifier if its power supply is stressed.

As in most things audio related it is a matter of trade-offs that wins the race. When we design class AB amplifiers—whether BHK, myself, Bob Stadtherr or Darren Myers—we start by assigning sufficient output current to eliminate notch distortion, then drag the amp into the listening room for the final bias settings.

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.

The 20 amp question

On my recent visit to Japan, I was working with a high-end dealer who had a beautiful set of Dan D’Agastino’s monoblock amplifiers on display. He and I both wanted to pit the BHK monos against these copper-beauties which we did. Helping him disconnect the D’Agastinos from the wall I noticed the amps sported 20 amp IEC inputs that needed a special power cord. Tracing the cable back to the wall socket I had to laugh. An adapter was in use. A 20 amp to 15 amp “cheater plug” because the dealer hadn’t a bonafide 20 amp AC receptacle—not only defeating the purpose of the 20 amp inlet—and limiting power cable selection—but also adding an unwanted layer between the wall socket and amplifier.

I see these 20 amp to 15 amp cheaters in a lot of installations and it raises several questions, one of which I address in this video.

The 20 amp connector does indeed permit greater current to flow into the amplifier. With a 15 amp connection, you can theoretically draw about 1800 watts, while a 20 amp connection affords about 2400 watts. Do we need that greater current? How many loudspeakers are using anywhere near the rated wattage available through a 20 amp connector, relative to the 15 amp?

I cannot think of many (actually any) loudspeaker systems that approach even the lower of the two numbers. So, I often wonder why 20 amp connections are used.

There are applications where it makes sense to me. Our newest Power Plant, the upcoming P20, is a good example. Here, we have a situation where multiple large power amplifiers might be plugged into this single P20 regenerator and the increased wattage potential offers greater headroom if nothing else.

How did we solve the practicality issue I reported from my Japan trip? By clever means. Our chief engineer, Bob Stadtherr, designed both a 15 amp and 20 amp IEC receptacle into the new P20. A foolproof door slides over the unused inlet so users can attach whichever power cable they wish.

We’ll be unveiling the new P20 beasts at RMAF in a couple of weeks.

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.

Paul is talking about breaking in audio and home theater components and this is something I truly believe in.

There are two different types of breaking in. One is breaking in new components, whether it is electronics, speakers or cables. I have found, with complicated electronics, that this can take up to 500 hours of playing time.

The Parasound JC-1 monoblock amplifiers I owned 10 years ago  come to mind here. They were the most extreme example I’ve experienced with break in of audio components. They sounded great out of the box and then gradually got darker and darker sounding. Then, they started lighting back up until they got what I considered neutral.  The they kept going lighter, until I thought their final sound was tilted up in the treble. Then they started a downward trend until they got it right. Nice amps….

The other is more what I would call warm up and to me, both need to happen with music playing. I warm my system up for at least an hour, each time I plan on listening, which is pretty much every day.

Here is Paul.
Saving up

The best sounding cables I have heard were a bare set of wires. Hardly practical in the real world, cables without shielding and insulation sound better than those with them.

We insulate cables so their conductors don’t electrically touch each other. We shield them with tin foil or woven metal to protect them from noise.

None of these techniques of isolation and noise reduction improve sound quality. Air is the best insulator and a noise free environment what we hope for if we want to avoid shielding. Unfortunately, dangling conductors in the air is as impractical as hoping for a noise free environment. Insulation and shielding are necessary evils.

The problem with insulators is energy storage. When a signal is passed along the conductor they cover, small portions of the signal are stored then released in the insulation. This effect can be measured and enumerated using what’s known as the Dielectric Constant. If we’re building a capacitor we want that number high. If it’s a cable, the lower the number the better.

Of the readily available insulation materials, Teflon has one of the lowest dielectric constants—far lower than standard insulation. But Teflon’s expensive and hard to work with, which is why it’s used sparingly.

In our ongoing discussion of break-in, I suspect it is this dielectric constant that changes with signal.