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The asking price of US$25 for the used Optimus SA-155 is a strong bargain, sitting well below the 25th percentile of US$28 from our ground truth database of 22 comparable listings. With the median at US$30 and the 75th percentile at US$34, this listing offers genuine value that far exceeds the typical used market range for this specific integrated amplifier.
This compact desktop amp is well-regarded among enthusiasts for its built-in loudness contour that extends bass response despite its low 1.8-watt RMS output, making it ideal for small speakers or turntables. Buying it at US$25 represents a smart opportunity to acquire a tested, original-owner unit with included accessories at a price point that is practically a steal compared to current market activity.
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.
