Commercial & Consumer Audio/Video Technology

About Us


A Little History

Quantum Products, originally established in 1997, developed Quantum Resonant Technology to investigate the application of electromagnetic field effects in biomedical electronics. The designer, Bill  Stierhout, worked in systems engineering for a defense contractor, as well as with leading pro audio companies - Rupert Neve Inc., and Mitsubushi Pro Audio in product management and support positions. In 1990 he started Coherence Systems, a technical consultancy company working with clients such as Warner Brothers, Sony, and Saban Entertainment. By 1995 he was marketing hifi accessory products for a sister company from which emerged Quantum Products and Quantum Resonant Technology.

The Nordost QRT brand has been quite successful  since 2008, embraced by audiophiles and the audio/video press world-wide.

Now, in 2019, ADD-Powr seeks to disrupt old standards with a new technology and create a new energy reference!

Quantum Symphony and Symphony Pro

His first devices, the Quantum Symphony, Symphony Pro, and ElectroClear appeared in 1999, rapidly gained significant critical acclaim particularly in the high-end AV market. The dramatic impact of these devices on display and sound quality was quickly appreciated. 

 Reviews of QRT Products:

- Positive Feedback

- Soundstage Magazine

In addition to the QRT branded products, his technology was licensed to companies such as Combak Corporation, Walker Audio, Russ Andrews Accessories, and Audio Magic.

In 2008 Nordost bought Quantum Products. They developed a line of products branded QRT, with great success. Quantum Resonance Technology has gained a much larger audience through the Nordost accessory products. 

Today: ADD-Powr

ADD-Powr has re-entered the high-end A/V market with a new product line.

About The Technology

ADD = Algorithm Digital Defined POWR = Energy

It’s a new reference for electronic signals and systems. How so? By literally re-referencing (biasing) the AC waveform with a field based technology.  The reference is an electric field of a specific frequency generated by software algorithms, amplified and induced into the immediate environment of electrical systems.

Whether analog or digital signals, audio or video systems, ADD-Powr reveals a new level of benefits with this new reference.

ADD-Powr provides additional strength to electrical signals large or small: as much as a 1 to 2.5 decibel (dB) increase in the S/N (signal-to-noise) ratio. * Further spectrum analysis tests have shown S/N ration improvements of 10 to 15%.

ADD-Powr creates a new reference. Nothing more nothing less.


The Problems of Conventional Power Conditioning

To audiophiles in the know, AC quality is a well known foundation of any high performance audio system. After all, every audio component takes incoming AC and modulates it to create the musical wave form we listen to. The phrase “garbage in, garbage out” applies very well to audio reproduction. Garbage AC feeding your components leads to less than ideal sonic output.  Unfortunately most attempts to improve or clean up AC is an exercise often fraught with compromise. Making sonic gains in one area usually compromises sound in another. Until now, clean, quality and compromise free AC  has been unobtainable. 

The daunting task of purifying AC  pollution is increasing almost daily. From over saturation of wireless networks in neighborhoods, to cellular phone use polluting airwaves and leaking into the grid, these problems are on the increase, not decreasing, and will only get worse as more and more “smart” appliances become part of our lives and homes. 

ADD-Powr creates a new reference.  Nothing more, nothing less.


Enter ADD-Powr

Add-Powr technology is unique because it is non-invasive. This means the ADD-Powr products are not directly inserted in the grid between AC line and component. Rather, they are a parallel EM field based approach to treating AC not only before power reaches the component, but inside the components themselves.

The added bonus of the EM field based approach is that it doesn't need to be physically inserted to the local AC grid between wall socket and audio component. ADD-Powr technology leaves impedance and peak current capability unaffected. Thus one of the biggest compromises of conventional power conditioning, current limitation, is eliminated.

It does so by actively emitting an ordered field that increases electromagnetic energy within your system's local AC grid and audio equipment.                  

Because it is an EM field based technology, both the placement and energy of the field will affect performance. This technology also benefits both reinforcement and spaced arrays to distribute its impact throughout the listening environment.

It is also compatible with any existing power delivery system including balanced power designs and many transformer isolated systems. 

*Pink noise speaker measurement made with a sound level (dB) meter.