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This is a buyer’s market for vintage budget amplifiers right now, and the US$30 asking price for the used Optimus SA-155 is fair, sitting right at the median of the 24 recent comparable USD listings where the 25th percentile is US$28 and the 75th is US$33. While some external listings show higher prices like US$40 or even US$105, the GROUND TRUTH data confirms that US$30 represents standard market value rather than a bargain or an ambitious overcharge.
The Optimus SA-155 is well-regarded among enthusiasts for its compact design and surprisingly extended bass response thanks to its non-defeatable loudness contour, making it a solid match for turntables or small desktop setups. Its chip-based output delivers about 1.8 watts RMS per channel, which is ample for near-field listening. At this fair price with no noted condition issues, it’s a worthwhile buying opportunity for anyone seeking an affordable, original-vintage stereo amp with included inputs for multiple sources.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.
Optimus is best known as a RadioShack private-label audio brand rather than an independent hi-fi manufacturer. The name traces back to RadioShack’s in-house branding, with “Optimus” used on some products from the late 1960s and more broadly on audio gear in the 1980s and 1990s. It does not have a clearly identifiable standalone founder in the way a dedicated hi-fi brand would; its heritage is tied to the RadioShack retail chain in the United States.
The line covered a broad range of consumer electronics, including stereo receivers, amplifiers, speakers, cassette decks, turntables, and later some home-theater and portable audio products. Depending on the era, many Optimus components were sourced from overseas OEM manufacturers, especially in Asia, and sold through RadioShack’s stores as house-brand alternatives to mainstream consumer audio lines.
In the market, Optimus sits firmly in the mass-market and mid-fi category rather than the high-end segment. Today it is mostly remembered by vintage-audio collectors and RadioShack enthusiasts, with certain receivers and speakers drawing interest for their retro appeal and occasional value. It is not generally regarded as a boutique or audiophile-first brand, but some models remain noteworthy for solid build and nostalgic charm.
See all Optimus listings on RADAR.
