Power Perfected: IsoTek V5 Sigmas Redefines Clean Audio

For discerning audiophiles, a power conditioner becomes an essential investment as their audio journey evolves. Power not only drives speakers but serves as a crucial carrier of musical signals. To experience music in its purest form, the power supply must be free from contamination.

British power conditioning specialist IsoTek addresses this challenge with their V5 Sigmas power conditioner, available in both black and silver finishes. Within IsoTek's current lineup, which includes the V5 and EVO3 series, the V5 Sigmas holds the second position in the V5 range and sixth overall, offering exceptional value in the mid-tier segment.

Since its establishment in 2001, IsoTek has focused exclusively on power isolation and conditioning technology. The company name itself—a fusion of "Isolation" and "Technology"—reflects their specialized expertise, with multiple patents incorporated into their product range.

The V5 Sigmas effectively eliminates two primary forms of power-related noise: differential mode and common mode interference. Differential mode noise originates from household appliances, while common mode interference stems from wireless devices and RF signals. As our homes become increasingly connected, power lines act as virtual antennas for interference, making clean power more crucial than ever.

Technical innovations in the V5 Sigmas include reduced resistance design, resulting in a 35% increase in current capacity and 40% improvement in conductivity. The unit achieves an impressive impedance approaching 0.92 through newly designed direct DC resistance technology. Internal wiring features solid-core, single-crystal, silver-plated copper conductors with Teflon insulation, while two Class-D amplifiers manage power distribution.

The V5 Sigmas employs a star-grounding configuration, connecting each ground point independently to a common reference, eliminating ground loops caused by potential differences between components. Protection features include 121,500A surge protection and dual circuit breakers—16A and 10A—offering superior current flow compared to traditional fuses, with contact surfaces over 1,000 times larger.

The rear panel houses seven outlets divided into high-current (red) and low-current (black) sections. The high-current section delivers 3,680W across three outlets, ideal for power amplifiers and active speakers, easily supporting two 1500W monoblocks. The four low-current outlets provide 2,300W total for source components like CD players, streamers, preamplifiers, and phono stages.

Each outlet operates independently, preventing cross-contamination between components. IsoTek's Adaptive Gating technology automatically senses load requirements, while their proprietary KERP technology ensures equal resistance and power delivery across all outlets.

The package includes IsoTek's Evo 3 Premier power cable, featuring silver-plated 6N OFC copper conductors, FEP insulation, and 24K gold-plated connectors—a cable that has earned five stars from HiFi Choice magazine.

In testing with a Blue Horizon Mains Noise Analyser, the results were remarkable. Direct mains power showed noise levels of 613 units (red warning), while the V5 Sigmas reduced this to 000 (green) on low-current outputs and an impressive 0002 on high-current outlets—exceptional performance considering the minimal filtering typically applied to high-current paths.

Listening tests with a system comprising a LINN LP12, EINSTEIN phono stage, Opera digital player, Melody WE2688, Xindak 20th Anniversary power amplifier, and ATC 50 speakers revealed significant improvements. The preamplifier connection showed approximately 25% enhancement in overall performance, with improved detail, tonal richness, and image focus. The power amplifier demonstrated a 15% improvement, delivering greater solidity and spatial expansion without the dynamic compression often associated with power conditioning.

The V5 Sigmas particularly excelled with vinyl playback, enhancing analog qualities while maintaining dynamic integrity. The transformation from a mechanical, constrained presentation to a more natural, engaging performance was unmistakable.

The IsoTek V5 Sigmas represents a significant advancement in power conditioning technology, allowing audio components to perform at their full potential while maintaining musical integrity and dynamic capability.