Tag Archives: amplifier

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.

Steam power

I love the term “running out of steam”. It’s an obvious reference to the beginnings of the industrial age where our world transitioned from animal power to steam power. When something runs close to its limits we say it’s running out of steam, or gas.

Recently there’s been quite a flap over on Ask Paul’s Videos. A question came to me about a subject that seems a tough one to grasp. Can preamp gain make up for low wattage? You can see the video response here.

Turns out this is a tough one for many to understand. I’ll see if I can approach it from a slightly different angle to chip away at the answer.

What’s confusing is the idea that if you put the same loudness music signal into both a big amp and a small amp, they produce the same number of watts (assuming they have the same gain – which most do).

To be more specific, let’s assume we have a 50 watt amplifier and a 500 watt amp, each with the same gain. Put 1 volt of music into either amp, and you will get (for this example) 30 watts out of both.

With me so far?

Using the same setup, now we will double the input voltage to both amps. Same thing happens, only the little amp will run out of steam—it can’t produce double the 30 watts and it clips. The bigger amplifier has plenty more steam available so it merrily outputs the expected 60 watts.

So, going back to the original question, can preamp gain make up for amplifier power, the answer is no. More preamp gain simply increases the input signal size to the power amplifier. It will still run out of steam at the same point. A preamp just gets it there quicker.

 

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.

Listening to power supplies

A power supply converts the AC wall voltage into something useful for our audio equipment—typically DC.

That conversion process of AC to DC sounds simple enough that we might imagine they are all the same, yet that would not be true—which is why many audiophiles have strong opinions on what’s best. Some are happiest when their power supplies are made from massive hunks of steel and copper festooned with a forest of capacitors. Others are thrilled when a thousand watts slip out of a tiny switch mode power supply without all the iron and parts of the aforementioned linear supply.

Yet, we don’t listen to power supplies. The sound of DC is zero. If you connect a battery to the input of your amplifier (don’t do it) no sound should come through the speakers.

Power supplies make no music, yet they are one of the most critical elements in a high-performance audio product. This is because they are the source of what follows. The amplification circuits are simply modulating the power supply in cadence with the input signal. The more rock-solid, low noise, and perfect the power source, the closer to live our music will sound.

Power supplies, and the power feeding those supplies, can often make more difference in sound quality than the circuits they feed.

If you’re the type that dive’s deep into a product’s technology, it’s equally important that you consider the power supply serving the amplifier.

A great amp is only as good as the power feeding it.