The NuPrime STA-9 is a compact yet powerful Class D amplifier that delivers a rich, engaging, and spacious sound. With a Class A biased JFET input stage and a high 550kHz switching frequency, it refines traditional Class D performance by reducing noise and enhancing tonal depth. Offering 120W per channel, or 290W in bridged mono mode, the STA-9 provides ample power while maintaining an effortless and refined musicality. Its robust build quality, premium connectors, and thoughtful engineering make it a compelling choice for audiophiles seeking high performance in a small footprint.

– John Grandberg, parttimeaudiophile.com

“How does 120W x 2 worth of hybrid Class A + Class D amplification for $649 sound? How about running a pair of them in mono mode for a total of 290W per channel? You’d think there must surely be some compromise involved yet try as I might I just can’t find it.These little fellows offer richly textured sound with an excellent soundstage and deep low-end extension, all in a tiny package. The amps build on the classic NuForce Reference models of yesteryear, but take on a subtly relaxed flavor where those older models could be a bit high strung. This is a hugely crowd-pleasing product worthy of serious attention despite its affordable nature”

– Philippe Daussin, qobuz.com

“Combination of energy and musicality
…NuPrime’s achievements have earned an excellent reputation, including its digital amplifiers, including the STA-9 model on power stages using a brand design and preceded by class A gain stages. Listeners get excellent sound results, which should reconcile the advocates of opposing opinions on the amplification classes!…”

– Jörg Dames, fairaudio.de

”…
– exceptionally clean, clear sound, not least promotes a very pleasant, seemingly organic timbres representation.
– tonal neutrality, the sound image becomes but absolutely consistent and coherent.
– an impeccable resolution, delivered pleasant long-term compatible sound.
– well-balanced voice or midrange.
– excellent space: precise focus
– we recommended listeners to experience with both the stereo and mono versions“