Why 8 Watts of Tube Amplifier Power is Quite Sufficient
8 watts sound as loud as 50% of a 100-watt amplifier. You can personally hear this in a head-to-head comparison between a tube and a transistor amplifier.
How much does the volume of an 8-watt amplifier differ from a 100-watt amplifier, given the same speakers with a sensitivity of 90 dB?
Sound volume is measured in decibels (dB), and increasing the amplifier’s power affects the sound pressure level (SPL). The basic principle is that to double the perceived loudness (an increase of 10 dB), you need to increase the power by a factor of 10.
To determine the difference in volume between an 8-watt and a 100-watt amplifier, you can use the following formula (see the picture below).
Thus, a 100-watt amplifier will provide a volume that is approximately 10.97 dB higher than an 8-watt amplifier when using the same speakers.
If you convert this to a percentage increase in volume, an increase of 10 dB is equivalent to doubling the perceived volume or a 100% increase. Therefore, 10.97 dB means an approximate volume increase of 110% compared to the 8-watt amplifier.
