Class T Amplifier

An amplifier is an electronic device that is used to boost the current, power or voltage of a signal. Amplifiers are generally used with audio devices in order to ‘amplify’ the sound signal, but are also employed in broadcasting and wireless communications. Amplifiers can be categorized into two types – power amplifiers, or weak signal amplifiers. Weak-signal amplifiers are utilized in wireless receivers and can amplify a very weak signal by eliminating internal noise and increasing the voltage of the signal. The device that is most effective for such use is the field-effect transistor. Power amplifiers are used in broadcast transmitters, wireless transmitters and hi-fi audio devices. Bipolar transistor is frequently used with power amplifiers.

Power amplifiers can be of many classes. Linear amplifiers are used in almost all kinds of home, car, PC and other audio input devices. However, these amplifiers are quite inefficient as they waste a considerable amount of power that they consume as heat. Linear amplifiers also require a great deal of power supply and large heatsinks – both of which increases the systems cost, weight, and size. Class D amplifiers; however, is more efficient when it comes to power usage. The Pulse Width Modulation (PWM) switching technology used in class D amplifiers enables it to use power more efficiently. However one might has to compromise with sound quality and fidelity with a class D amplifier which is not an issue with a linear amplifier.

A breakthrough innovation that addresses both power efficiency and sound quality has been introduced by Tripath, a Silicon Valley start-up in 1998. Tripath came up with a Digital Power Processing (DPP) circuit topology that is incorporated in a new class of amplifier called the “class T” digital amplifiers.

Using voice/data communication theory, The Tripath class T amplifier uses proprietary adaptive processing that will get rid of the number of different switching artifacts that is generally encountered in conventional PWM digital amplifiers. The class T adopts a much higher than PWM amplifiers to provide a higher signal resolution with minimum distortion. According to Tripath, there is a considerable difference in the waveform of PWM amplifiers and class T amplifiers. The waveform of a class D amplifer would show a pulse-width varying digital signal, along the set frequency of the wave generator, whereas a class T amplifer would show a complex digital waveform at varying frequency. The output transistors in class T amplifiers are switched in a manner similar to the spread spectrum technology. The frequency varies at a rate of up to 1.5 MHz.

These lead to an exceptionally low intermodulation distortion and IHF – IM figure in the class T amplifier, both of with are less than 0.1%. Class T also supports a noise floor of -100 dB, and a range larger than 120 dB. With eighty percent power efficiency, the class T amplifier reduces power consumption, and also leads to a low cost.

After Tripath, the class T technology has been incorporated by a number of other audio device manufacturers. A popular amplifier of this sort is the Sonic Impact Tripath Amplifier. The ‘chip’ technology introduced by Tripath is what makes this amplifier a cheaper one, compared to traditional linear or class D amplifiers. At US $39.95, this amplifier, when combined with suitable speaker drives, is considered to be a good value for the price, according to users. Users have claimed the Sonic Impact amplifier to be exceptional in terms of clarity and transparency of sound and voice. It has very low power consumption, and delivers high quality performance at an exceptionally low price. However, there are slight imperfections in the amplifier in terms of overall dynamics. Nevertheless, one cannot expect anything more than what it already delivers at such an affordable price. For audiophiles at least, the Sonic Impact amplifier is truly a small and compact wonder in the amplifier technology.

This Class T Amplifier Review is Written/Updated on Jul 29th, 2010 and filed under Consumer Electronics. Both comments and pings are currently closed.

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