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This is a seller’s market for this kind of vintage Class-A power amp, but the asking price of US$1,300 still lands well above the typical used level: the median is US$225, the 75th percentile is US$625, and this sits far beyond that. That makes it ambitious rather than a fair-market buy, even allowing for the clean recap and rarity.
What keeps it interesting is the Bedini/QSA cachet: these are loved for their smooth, lively presentation, strong midrange purity, and “musical” Class-A character that can make sensitive speakers sing. A full recap is a real plus, since these amps are now old enough that service history matters. Still, at US$1,300, the buyer should want proof of the recap quality, stable bias/heat behavior, and clean channel balance before paying up.
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.
