Background
In 2005, NuForce invented an amplifier that utilizes self-oscillating switching principles in an analog-based
topology (US patent #7,221,216 ) as a significant departure from bulky Class A/AB designs using tubes or
transistors, and Class-D digital designs that convert signals into digital data. Thanks in full measure to
unique innovations, the NuForce Reference 9 amp received the Power Amp of The Year 2005 award from The
Absolute Sound, a prestigious American audiophile magazine. Subsequent versions of the Reference 9
received similar awards in Japan and France.
In 2014, NuForce, having decided to focus on mobile products, sold the high-end line along with its
technology to investors who then created NuPrime Audio. Under the leadership of NuForce co-founder and
original CEO, NuPrime has assembled a design team comprised of talented engineers who earlier worked on
NuForce’s high-end line along with newly recruited experts in switching-power circuit design. Recent
developments have made it possible to redesign NuPrime’s switching amp topology from the ground up in
order to create a new generation of amps that allow NuPrime to precisely control the sound characteristic.
NuPrime is not a Switching Digital Amplifier
Switching Digital Amps, commonly known as Class-D, first appeared some decades ago. From the start, Class-
D showed enormous potential along with significant shortcomings: limited usable bandwidth, and a fixed
saw-tooth waveform for audio- signal modulation, the latter producing jitter that effectively masks low-level
signals.
Instead of the conventional saw-tooth configuration, NuPrime’s patented circuit design uses a naturally
occurring analog-modulating signal that adds neither noise nor jitter. Rather than reverting to off-the-shelf
solutions, NuPrime’s in-house advances have further unlocked the switching amp’s potential without the
difficulties pure digital-switching amplifiers simply cannot avoid – in other words, the best of both worlds.
Goodbye, heat. Goodbye, hernias.
Once upon a time heat and bulk were badges of status. Today, they’re the bane of obsolescent technology.
NuPrime amps switch at 600,000Hz – more than 10X the CD sampling rate. At these frequencies,
transformers and capacitors work far more efficiently, making it possible to reduce their size. Typically, Class-
A amps rarely utilize more than 30% of the power they draw; the rest is wasted as heat. High operating
temperatures also shorten the useful life of the electrolytic capacitors used in abundance in these designs.
A comparison with traditional designs is mind-boggling. A NuPrime amp, small enough to sit on the palm of
one’s hand, is, typically, 85% efficient – in practical terms, cool-running and easy on the utility bill.
Advantages of NuPrime Amplifier Technology
1. High bandwidth. Truly faithful reproduction of music demands bandwidth, and plenty of it. Inadequate
bandwidth withholds important spatial information and tonal complexities. NuPrime amps deliver high
bandwidth with a ruler-flat response from 20 to 50,000Hz. Only a very few, very expensive linear
amplifiers are capable of achieving that. This bandwidth allows NuPrime to amplify complex music with
faithfulness far beyond the capability of conventional amps, with particular regard to a vast soundstage
– accurate spatial information delivered in full.
