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At £69, this sits well below the 25th percentile of £101 and far under the median of £357 across recent comparable GBP listings, so it reads as a strong bargain rather than a merely fair ask. Against that market backdrop, the price looks especially attractive for a compact digital DAC/DDC-style unit like this, where the used market is often driven more by performance-per-pound than by brand cachet.
What makes it worthwhile is the usual appeal of these small XMOS-based boxes: handy as a clean USB/coax bridge, easy to drop into a desktop or secondary system, and typically good value if you want a straightforward digital upgrade without spending much. At this price, the main upside is simple—low risk, strong resale cushion, and enough headroom that even a modestly used example can still make sense, provided it powers up cleanly and comes with the needed cable or PSU.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.
Quantum Science Audio (QSA) emerged in early 2020 under the leadership of Steven Tsang, an electronic engineering expert with deep roots in audio consulting. Based in Scottsdale, Arizona, with ties to Hong Kong where Tsang honed his expertise, the brand quickly carved a niche through relentless innovation in power components. Drawing from over two decades of proprietary research, QSA embodies a fusion of technical discipline and audio obsession, prioritizing subtle yet profound system enhancements.
The company's focus centers on high-performance aftermarket fuses, including thermal, slow-blow, automotive, and specialized AC variants like inlets, outlets, and panel breakers. QSA also extends into power receptacles and related accessories, all engineered to eliminate so-called "bottlenecks" in signal paths. Their lineup spans accessible entry points at around $28 to ultra-premium models commanding exorbitant prices, reflecting escalating tiers of advanced materials and quantum-inspired treatments.
In the hi-fi market, QSA occupies a polarizing boutique position among high-end enthusiasts, celebrated by some for transformative sound improvements in power delivery. Top models attract audiophiles chasing marginal gains, though skeptics dismiss the claims as overreach amid long production lead times. This niche status suits discerning buyers open to experimental upgrades in an otherwise crowded field.
See all Quantum Science Audio listings on RADAR.
