The 10 Best Mono Amplifiers
History Of The Audio Amplifier
Triode-based continuous wave radios also allowed amplitude modulation sound transmission, commonly known as AM radio.
In 1906 the first electronic device capable of amplifying sound was created and it was called the Audion and was invented by Lee De Forest, who was an electrical engineer. The Audion was a triode, meaning it consisted of three electrodes that were placed inside of a partially evacuated glass envelope or tube. The invention of the Audion hailed the beginning of the electronics age and made possible things such as amplified radio and long-distance telephone calls.
The Audion tube contained a small amount of gas because De Forest believed it was necessary for the amplification properties. As it turned out, not only was the gas not necessary, it actually hampered the device's ability by limiting the dynamic range and giving the sound nonlinear characteristics, making the amplification erratic. Despite its shortcomings, the Audion was used to build the first successful electronic oscillators and amplifying radio receivers. Triode-based continuous wave radios also allowed amplitude modulation sound transmission, commonly known as AM radio.
By 1913, another inventor named Harold Arnold, who had purchased the rights to De Forest's Audio, was working on developing triode amplifiers with a higher vacuum. This device was known as the Pliotron. Eventually all of these partial-vacuum amplifiers were replaced by fully-vacuumed tube amplifiers. Without the invention of the Audion and the triode, most mass communication devices such as TV, radio, and the public address system would never have been possible.
As transistor technology become less expensive and more practical in the 1970s, transistor-based amplifiers began to replace the older vacuum tube models, but for many years after their introduction, they could not match the former's sound quality. This led audiophiles to believe that tube-based amplifiers were inherently superior. Over time, electrical engineers learned to better understand the causes for the distortion process within transistor amplifiers and eventually correct it. Currently they are far superior to the vacuum tube amplifiers.
Mono Vs. Stereo: What's The Difference?
Mono and stereo is a source of much confusion for the average consumer. Some people seem to think mono sounds better, while others feel that stereo does. Many receivers and head units these days can electronically switch between stereo and mono, but not so with amplifiers. If you have ever been listening to music in your home or car and switched from stereo to mono, you may not have heard any difference. This is because the difference is only noticeable when the music or recording has been produced in one channel, or has been recorded at a louder setting in one channel than the other.
Consider surround sound when watching a movie. Those times when you are watching a movie with surround sound and it sounds as if a noise has moved from one side of the room to another, that is making use of stereo sound recording and playback. If you were listening to that on a mono system, it would not have created that effect of movement. The rest of the time when watching a movie, it would have made no difference whether you were listening to a mono system or a stereo system as the sound was recorded and intended to be played back on both sides at the same level.
A stereo amplifier has two independent channels, the left side and the right side. These two signals are similar, but not the same. Sound or voice can be produced on just one channel, which can be used to give music and sound effects a sense of depth. They can also be produced slightly higher on one channel than the other to make a sound that seems to have originated off center. If the sound on the left channel is produced slightly higher than sound on the right channel, it will sound as if it is coming from slightly off to the left.
In a mono system, all of the audio signals get mixed together and then routed through a single audio channel. This means that even if a mono system makes use of multiple speakers, there will be no sound difference between them as the signal coming out of every one will be exactly the same.
Understanding Amplifier Specifications
There are a few important terms one must understand when considering which amplifier to purchase. Power output, which will be rated in watts, translates to how loud the amplifier is capable of getting. The larger the speakers, the more watts your amplifier will need.
This tells you how much background noise the amplifier will make.
Total harmonic distortion is often ignored by consumers, but actually makes a big difference in sound quality. It tells you how much effect the amplifier will have on the sound output. The higher the total harmonic distortion or THD, the more distorted the sound will be from the original recording. Ideally one should look for an amplifier that has a low THD rating.
Many amps also site the signal-to-noise ratio or SNR. This tells you how much background noise the amplifier will make. If the volume is set very loud, one may not notice the background noise of the amplifier, but at lower volumes, the electronic hum can be quite noticeable. It is best to find an amplifier with a higher signal to noise ratio. The higher the signal to noise, the less noticeable the electronic noise will be.