BETA
RADAR is in beta — expect errors. Accuracy and coverage improvements are shipping daily.
LIVE
Waiting for new listings…
0 other audiophiles online

Our Thoughts RADAR AI

This is a buyer’s market at the current asking price, and the listing is ambitious versus your recent comp set: at US$1,300, it sits above the US$1,220 75th percentile and well over the US$1,140 median. For a used amp, that means you should expect either standout condition, a notably strong service history, or some included extras to justify the premium.

The reason it can still be a worthwhile buy is simple: this is a respected high-current stereo power amp with the kind of control and drive that still appeals to serious listeners. If it’s clean, original, and fully healthy, the upside is the usual one with well-regarded vintage solid-state gear: big, authoritative sound and long-term satisfaction. At this price, I’d want clear proof of condition and servicing before calling it a no-brainer.

Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.

About Threshold

Threshold Audio emerged in Sacramento, California, in 1974, founded by renowned audio engineer Nelson Pass alongside graphic designer René Besne and Joe Sammut. Pass, a pioneer in amplifier design, launched the brand with the groundbreaking Threshold 800A power amplifier in 1975, introducing a novel sliding bias system that boosted Class A efficiency while employing 48 output transistors in a sophisticated triple-series/triple-parallel configuration. This California-rooted heritage defined Threshold as an innovator during its original run, which spanned until the mid-1990s, after which the intellectual property changed hands, including a 1994 acquisition by investor Randy Patton, who integrated it with PS Audio and relocated operations to Camarillo.

The brand focused squarely on high-end amplification, producing iconic power amplifiers like the 400A and 800A, the Stasis series renowned for their balanced Class A performance, and preamplifiers such as the NS10, SL10, and FET range including the FET-1, FET-2, FET-9, and FET-10. Later designs, like the T-200 by engineer Michael Bladelius, continued this legacy. Threshold eschewed speakers, turntables, DACs, headphones, or cables, concentrating instead on pure analog amplification that prioritized sonic purity and robustness.

Threshold holds a revered position as a vintage high-end icon, cherished by collectors and audiophiles for its enduring sound quality and Pass's technical wizardry. Once a market leader in premium solid-state gear from 1975 to 1992, it remains a sought-after name in the used market, embodying boutique excellence rather than mass production, with modern revivals under Threshold Audio sustaining its elite reputation.

See all Threshold listings on RADAR.

More 400A listings