4-Pole Technology

In classic power supply capacitors, the charging path (from the rectifier into the capacitor) and the load path (from the capacitor to the amplifier stage) run through the same internal current path over long stretches. As a result, the unavoidable parasitic components – ESR (equivalent series resistance) and ESL (self-inductance) – do not act only “inside the capacitor” but also directly shape the supply at the output stage. Especially with pulse currents and ripple components, this creates shared voltage drops and modulation.

Mundorf's 4-pole technology solves this problem by design: input and output are routed as separate terminal pairs. Charging/ripple currents are routed via the input, while the power stage is supplied via the output. Charging and load current paths thus share considerably less common impedance.

Electrical characteristics

Reduced common impedance in the load path

Charging and load current share less internal resistance and internal inductance. This reduces voltage drops in the critical load path.

More favorable behavior with pulse currents

Load impulses imprint themselves less back into the charging path, and rectifier impulses/ripple currents couple less into the supply of the output stage.

More effective use of the capacitance in the real system

The capacitance “works” closer to the amplifier stage, because the current path within the capacitor is routed in a more defined way.

Macro-microphony

We understand macro-microphony as significant modulation of the supply caused by mechanical movement or strongly varying load forces. A more stable current path routing reduces the tendency for load impulses to appear as perceptible supply modulation (“pumping”). The 4-pole technology thus contributes to stability under dynamic load – complementing mechanical measures such as fixation and winding stabilization.

Micro-microphony

Micro-microphonic effects appear as the finest modulations in the current path. Separating input and output reduces the likelihood that charging/ripple currents imprint fine modulation components into the supply branch of the amplifier stage. This supports a calm, clean supply even with complex signal patterns.

Sonic Character

In reproduction, the 4-pole technology manifests as authority: more control in dynamic passages, more stable impulses, a calmer overall impression and more precise imaging. Especially with level peaks and complex music, the sound picture remains stable, because the supply is less prone to dips or modulation.

Typical Applications

• Power amplifier supplies (class A/AB/D) where pulse currents and load steps are high
• Power supply banks in active systems and signal-processing devices with high dynamic requirements
• Applications where “energy at the stage” is decisive: fast transients, controlled bass, a quiet background
• Upgrades/service, when an audible improvement in power supply stability is desired