RADAR is a price search engine. We link to the original listing — we never sell direct. Transactions happen on the source site.
The US$21 asking price for the used Optimus SA-155 is a genuine bargain, sitting well below the 25th percentile of US$28 from our 24 recent comparable listings. With the median at US$30 and the 75th percentile at US$33, this listing is significantly underpriced relative to the typical used market, offering a clear buying opportunity for enthusiasts seeking an affordable entry into vintage integrated amplifiers.
This small SA-155 is well-regarded for its surprisingly extended bass response thanks to its unique, non-defeatable loudness contouring scheme, which makes it a fun choice for record players or portable sources. Its 1.8 watts RMS per channel is modest but sufficient for small rooms or desktop setups, and the front-panel 1/8-inch input adds modern convenience. Since the price is far below median and the listing appears clean, there are no material caveats to raise—this is a timely, low-risk purchase for a well-loved, simple amplifier.
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.
