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*US* BUYERS IGNORE MESSAGE ABOVE SAYING THERE IS TARIFFS FOR THE BUYER THAT IS NOT TRUE! I PREPAY ALL US BUYER TARIFFS NO TARIFFS FOR YOU TO PAY, YOU PAY IS ONLY AT CHECKOUT NO HIDDEN FEES*The Russound P75 Stereo Power Amplifier is a highly sought-after audiophile piece that has been freshly serviced. This rare amplifier from the renowned brand Russound is designed to deliver high-quality sound for your stereo audio system. With its model being the P75, this power amplifier is sure to provide excellent performance and a premium audio experience for your home entertainment setup. Perfect for audiophiles looking to enhance their listening experience, this amplifier is a valuable addition to any home audio setup.
This is a buyer’s market at this price point: at US$166, this sits comfortably below the US$231 median and just above the US$92 25th percentile, so it reads as a solid value rather than a stretch. It is not a screaming bargain, but it is still priced attractively for a used power amp in this category.
The upside here is straightforward: a serviced stereo power amp from a respected niche brand can be a very practical grab for someone wanting robust, no-nonsense amplification without paying collector money. The “freshly serviced” note matters more than hype here, because with older amps the real win is a clean, ready-to-run unit; if the service is documented and the cosmetics are decent, this looks like a worthwhile buy.
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.
