Power Supply Capacitors

Why power supply capacitors are so decisive for audio

A high-quality power supply determines how sovereignly an audio device performs under real music loads. Essentially, the energy from the power supply is to an amplifier what the fuel in the tank or the energy in the battery is to a car: without sufficient available energy, no engine runs – and no amplifier works. And this energy must be there exactly when it is needed: without delay, without dips – and precisely where it is needed: directly at the actual amplifier stage. Power supply capacitors smooth the supply voltage, buffer load steps, and determine how stable the supply remains when dynamics, impulses, and high levels occur simultaneously. In short: without a good power supply, no amplifier can develop its full potential.

Different amplifier concepts – different requirements

Depending on the circuit concept, the requirements for the reservoir capacitor change considerably:

• Class A: high continuous current → temperature resistance, low drift, and long-term stability are decisive.
• Class AB: strongly varying loads and high pulse currents → peak current capability, low internal resistance, and minimal supply dips are the priority.
• Class D: fast current edges and high-frequency components → what is required is broadband low impedance and a stable, low-noise supply.
• Tube circuits: high voltages and often classic layouts → in addition to electrical performance, the appropriate design plays an important role, especially for faithful, original-style builds.