Power Amplifiers

Power Amplifiers

A power amplifier, or power amp takes a low-power, line-level signal and boosts its current and voltage to drive heavy loads like loudspeakers, headphones, or radio antennas. As the final electronic stage before the signal physically leaves the system, it deals with massive electrical currents, so you need to get it right! Shopping Power Amps at Markertek comes with confidence; we supply industry-trained expert support and technical advice from start to finish!

Core Classes of Power Amplifiers
Power amplifiers are broadly categorized into "classes" based on their internal circuit configuration and how long the output transistors conduct electricity during an audio cycle:

• Class A: Transistors conduct electricity 100% of the time (360° conduction angle). They deliver the highest linearity and zero crossover distortion but suffer from terrible power efficiency, generating massive amounts of heat.
• Class B: Uses two transistors in a "push-pull" setup, each handling exactly half of the signal cycle (180° conduction angle), increasing efficiency but introducing crossover distortion.
• Class AB: The industry standard for high-fidelity audio; both transistors run slightly past the half-cycle mark (180° to 360° conduction angle), successfully wiping out crossover distortion but keeping the increased energy efficiency.
• Class D: A high-speed switching design where transistors act like rapid on-off switches, producing 90% power efficiency, virtually no heat in lightweight, compact forms.

The Math of Speaker Matching
A power amplifier must be carefully matched to your passive speakers to prevent sound clipping; an underpowered amplifier pushed past its limit can damage speakers.

• Impedance (Ohms): Speakers typically present a 4-ohm or 8-ohm electrical resistance; choosing the proper rating ensures it handles low impedance without overheating.
• Continuous Power (RMS): Always match your equipment using RMS (Root Mean Square) wattage, not "Peak" or "Max" wattage. Your amplifier should ideally deliver 1.5 to 2 times the continuous RMS power rating of your speakers to provide safe headroom.

We Can Help!
Here at Markertek, our selection of power amplifiers is chosen from top brands like LEA Professional, ART, Crown International, and QSC, building for broadcast, mobile networks, live sound reinforcement, theaters, and automation. Our Sales Engineers are ready to put their industry knowledge and expertise to work for you; reach out!

FAQ

Where are different class Power Amplifiers used?
Class A is common in high-end, studio, home audio, and headphone sound. Combination Class AB powers Studio Monitors, Home Theater, Guitar Amps, and AV audio. Class C is for radio transmitters and oscillators, and Class D is in portable Bluetooth speakers and modern live music. G and H handle high-power, heavy-duty, professional concerts and live events.

What is Linearity in Audio Power Amps?
Linearity is the ability to take a small audio signal and make it bigger without changing its shape to avoid distortion. A linear amplifier acts like a magnifying glass for sound waves, producing clean, accurate, and faithful sound reproduction.