Yesterday, Nick and I had the pleasure of hosting a focused demo session with IsoTek Systems, and even with our expectations already high, the results were nothing short of revelatory.

We tested the V5 Polaris power cleaning block in tandem with the V5 Syncro Uni 10 DC Blocker — a pairing that sits comfortably within reach for many serious systems, yet delivers the sort of upgrade that leaves a lasting impression.

The change was immediate and unmistakable. The noise floor dropped, allowing more music to come through unimpeded. The soundstage opened up, with greater width and separation, making it easier to pick out individual instruments in complex recordings. Vocals took on a more lifelike presence, with a sense of body and realism that simply wasn’t there before. It didn’t feel like a tweak — it felt like a system upgrade.

The complete IsoTek package we used in the demo comes in at £1,595, and for what it brings to a well-put-together system, that feels like exceptional value.

If you’ve never heard what proper power conditioning can do — especially with a DC blocker in the chain — we’d love to demonstrate it for you. It doesn’t add anything to the music… it simply gets out of the way.

Why Is There DC on the Power Grid?

Your hi-fi system is designed to work with clean, symmetrical AC power, but what it often receives is anything but. One of the main culprits is DC offset, a small but disruptive imbalance on the mains supply that stems from the way modern devices interact with the electrical grid.

Anything with a motor or a switch-mode power supply can introduce this issue — think fridges, washing machines, LED lighting, phone chargers, and TVs. Increasingly, solar panel inverters and home battery backup systems are adding to the problem, feeding distorted current or asymmetrical loads back into the household supply.

The result? A DC component riding on your AC waveform, which can cause toroidal transformers in hi-fi components to buzz audibly or operate less efficiently. But even if you don’t hear it, your gear feels it — transformers can saturate, dynamic range may shrink, and resolution suffers.

That’s where the IsoTek V5 Syncro Uni comes in. It actively removes DC offset and realigns the waveform, allowing your system to breathe freely again, with improved transparency, tighter imaging, and greater musicality.