Linear Power

EIN 350L RF Power Amplifier 50 Watts Linear 550L 1711
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High power Wifi Wlan amplifier 80211b 5 Watt COFDM linear HPA SSPA
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PHASE LINEAR D 500 POWER AMPLIFIER ONE OWNER COMPLETE PHASE LINEAR SERVICED
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MODIFIED LINEAR POWER DPS500 AMPLIFIER PAIR TOP NOTCH SQ OLD SCHOOL QUALITY
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ENI 503L RF Power Amplifier 3 Watts Linear
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ENI 411LA RF Power Amplifier 10W Linear 150 KHz 300 MHz EI 411 LA Warranty
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Linear Power

How Tiny Can They Get? - The Latest Super-Miniature Audio Power Amps

New generation super-miniature amplifiers are a result of the same miniaturization that has caused computers and cell phones to shrink. Products are shrinking at a rapid pace. At the same time, manufacturers are packing in more and more features. The majority of audio amplifiers would be tube amps in the past. Although a large number of fanatics still is fond of tube amplifiers, they have been substituted by solid state amps for the most part.

While historically there would be separate pre amp and power amp stages, today's solid-state amp combine everything into a neat box no larger than the size of a VCR. New developments in audio technology in regard to power efficiency of have allowed the development of a new generation of super-miniature audio amplifiers, such as Amphony’s microFidelity Model 100. Even though these mini amps provide up to 50 Watts - enough to drive a speaker to high volume, they are no larger than a deck of cards.

"Class-A" and "Class-AB" amplifier topologies were the two primary amplifier architectures of past audio amplifiers. These technologies have relatively low power efficiency. Only a small percentage of the consumed energy - typically in the order of 20% to 30% - is actually converted into audio by analog amplifiers. The remaining portion is radiated as heat. Analog amplifiers hence need considerable cooling which is done by heat sinks that are often bulky and prevent the amplifier from being made very small.

The "Class-D" topology of digital amplifiers offers higher efficiency than analog amps. The efficiency typically ranges between 80% and 95%. This allows digital amps to be miniaturized. One main disadvantage of "Class-D" amplifiers is the fact that digital "Class-D" amplifiers use a switching stage at the output which causes non-linearity and consequently some amount of distortion of the audio signal. This downside has slowed the progress of digital amplifiers.

More recent "Class-T" and newer "Class-D" amplifier architectures, such as Amphony’s Model 100, incorporate a feedback mechanism where the output of the amplifier is fed back to the input. Using this design, the amplifier is able to compensate for errors brought on by the switching output stage. Amplifiers based on this design are able to accomplish low audio distortion similar to previous analog amplifiers but at the same time the power efficiency of digital amplifiers.

These new generation miniature audio amplifiers open up applications where previous amplifiers would fail, such as speaker installations where space is premium, such as in-ceiling speakers and applications that attach speakers to a cable box or DVD/MP3 player.