First Generation Amplifier Board (V1)

Early in our existence as a company, NuForce demonstrated that a switching amplifier (also known as Class-D) performs as well or better than traditionally designed high-end amplifiers. Indeed, in 2005 The Absolute Sound (USA) declared our Reference 9 amp in its Version 1 iteration Power Amp of The Year. We followed up with the Reference 9 SE (Special Edition) in late 2006.

Second Generation Amplifier Board (V2)

Our V2 amplifier is an overall optimization the V1's circuit and layout. The V2 board looks quite different from that of the V2. More to the point, the V2 board outperforms its predecessor in several key respects: a 20 dB-lower noise floor (that's no typo) and an output stage that achieves 85% efficiency. And we abbreviated the current-delivery pathway in order to achieve a 20% improvement in through-put. Further, we incorporated everything we learned in developing our top-of-the-line 9 SE amp into our standard amplifier board.

Third Generation Amplifier Board (V3)

V3 significantly improves control and feedback. Don't be fooled by V3's superficial resemblance to V2. Improving control and feedback posed daunting challenges. The Reference 9V2SE has been widely reviewed as one of the best amplifiers to be had, classification notwithstanding.

Have we taken V2 closer to perfection? Most definitely! Superior feedback characteristics and overall control produce a more linear signal across a wider bandwidth - in point of fact, an astonishing 130KHz. Harmonic distortion and noise have been significantly reduced.

Note V3's improved FR measurement. Note also the absence of variations. (Many amplifiers exhibit FR variations from +/- 0.5db to 1db through 20Hz to 20khz - in other words, the audio frequency range.) Our FR remains within +/- 1db variation until it reaches 130KHz. This is astonishing, for a Class-D or any other manner of amp.

Frequency Response Comparison

Notice that V2 has improved bass frequency.

V3 shows a significantly improved FR measurement. Note that there is practically no variations (many amplifiers have FR variations of +/- 0.5db to 1db from 20Hz to 20khz) within the audio frequency range (20Hz to 20kHz) and the FR stays within +/- 1db variation until it reaches 130KHz. This is astonishing for a Class-D amplifier.