More power for better sound at low volumes?

When you operate a high power amplifier at low power levels quite often you have higher levels of distortion. This is because most high power amplifiers are push-pull and with rare exception, most push pull amps (tube or solid state) will have their lowest distortion at some point well above zero watts and then the distortion increases again as power continues to decrease.

At low power in particular, it really is that 'first watt' that makes the difference! Due to the ear's masking principle, if higher distortion is present, detail will be obscured IOW such an amp will be less detailed at lower volume levels. Also as others have pointed out the noise floor will be higher too.

Amps that do not exhibit this dip in distortion, IOW amps that have a linear decrease in distortion as power goes down to zero, will have unmeasurable distortion as power levels fall below 1 watt. They fall into two categories: either SET, or fully-differential with little or no negative feedback.

I can go into the why of this if anyone wants but it gets technical.

Unsound, more power in the amp will not reject external noise. The way to do that is to have a fully differential balanced circuit (whether tube or solid state).

Listening to most really good stereo recordings on headphones is in fact the stereo equivalent of watching a 3-D encoded movie without the required glasses. Room acoustics are the equivalent of the 3-D glasses for a stereo recording. And of course no two rooms share exactly the same acoustics, including studio or hall recorded in and listening room at home, so the reproduction will most likely always be different to some extent and not exact no matter how "good" the stereo system is.

06-21-12: Unsound
Al, Perhaps erroneously, I would have assumed that "all else being equal" extra power would have provided the muscle to reject external noise from seeping in?

Hi Unsound,

No, I don't see it that way. Higher amplifier power will loosely correlate with higher amplifier gain, since amplifiers tend to be designed such they they will be driven to their maximum power capability, whatever that may be, when their input voltage is in the same general area (commonly, although of course not always, in the general area of 1 to 1.5 volts, for unbalanced inputs).

So as I indicated, any noise that is generated or introduced downstream of the volume control will, more often than not, be amplified by a greater amount if the amplifier is higher powered. (Noise originating upstream of the volume control will normally be unaffected by that gain difference, because the volume control setting will be turned up or down to compensate for the gain difference, affecting the signal and noise that originates upstream equally).

Best regards,
-- Al

IMO clarity/resolution is the solution to better sound at any volume. It starts with your soure and then the preamp. All that gets passed through to your amp which basically just magnifies the signal. Most preamps have to use a little juice to get them sounding good basically becasue of the caps in the signal path. Use a direct heated triode preamp that is transformer coupled and you won't have that issue. If you are using a CD Player how old is the laser? That can have a significant affect on clarity/resolution.

Happy Listening.

Mapman,
You raise an excellent point with nearfield listening. I often use to pull my chair up to within 3 ft of the speakers ( Martin Logan CLS modded at the time ) and listen nearfield. I believe it removes the room effects and you get a much larger soundstage behind the speakers and can hear into it.
Reminds me of a one on one I had many years ago with Dave Wilson of Wilson Audio. He positioned me in a nearfield position, 3ft from each speaker and dead centre, and proceeded to run through many of his recordings to demonstrate his recording and microphone techniques. In this nearfield position all was revealed.