Two ways to clean power.
Only one disconnects you from the grid.

In a toroidal isolation transformer there is no direct wire between the wall socket and your equipment. Power crosses from the primary to the secondary winding by magnetic induction alone. That break in the circuit severs the path for DC offset, ground-loop noise and high-voltage line spikes, so they never reach your components. Passive filters cannot do this: the wall and your system remain electrically connected.

Ordinary mains is unbalanced: one live conductor at 230 V (or 120 V) and a neutral at roughly 0 V, both referenced to earth. A balanced transformer splits its secondary winding around a centre tap tied to earth, creating two legs of equal and opposite voltage: +115 V and −115 V on a 230 V supply, or +60 V and −60 V on a 120 V supply. Common-mode interference arrives on both legs in identical phase, so it cancels symmetrically at the load instead of being dumped elsewhere.

Only if it is too small. An undersized transformer compresses dynamics just as badly as a restrictive filter. A large, well-designed toroid has very low DC winding resistance and a massive core, so it behaves as a local energy reservoir and delivers sudden current bursts without choking transients or bass impact. This is why Audes builds its conditioners around generously sized cores, such as 3000 V∙A for the main transformer of the TT-3200DC and 3300 V∙A for the DT-3600.

The transformer stops DC offset from reaching your equipment, but the DC still flows through its own primary winding and can partially saturate the core, which makes it buzz mechanically. A DC blocker removes that offset before it reaches the transformer. Every current Audes conditioner has one built in. On the DT-3600 it is switchable from the rear panel so it can be used only when your grid needs it; on the TT-3200DC it is always active.

For lower-current source components, where rack space and weight are tight, a passive filter can be a sensible and affordable choice, and it is very good at targeting specific high-frequency RF bands. Its limits show with power amplifiers: series chokes raise source impedance and can soften transients, and the noise it removes is usually shunted onto the safety ground, from where it can migrate into other connected equipment.

Regenerators rectify the mains to DC and use a built-in amplifier to synthesise a fresh sine wave. They isolate well and block DC completely, but their current delivery is capped by the size of that internal amplifier, they run warm with typical efficiencies of 50–70%, and some need cooling fans under load. A large toroid has no such ceiling on peak current and runs far cooler.

The weight is the iron and copper that make the performance possible: a reference toroidal conditioner typically weighs 30–60+ kg, the TT-3200DC weighs 37 kg and the DT-3600 61 kg. Plan for a solid floor position or a reinforced rack, much as you would for a large power amplifier. Although toroidal cores contain almost all of their magnetic field, we still recommend keeping any conditioner a reasonable distance from turntables and phono stages.

It depends on what you power. Large power amplifiers and multichannel cinemas benefit most from the highest ratings and the dual-transformer DT-3600 and TT-3200DC, which add an isolated group for digital devices. Integrated amplifiers and complete stereo systems are well served by the mid-range models, and sources, preamplifiers and compact systems by the ST-900DC. Our dealers can recommend the right rating for your equipment.