Copper Reference

Copper Reference

Premium Stereo Audio Interface

A hand-built American hot rod of unparallelled quality and performance.

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The very best components available and an advanced design ensure the ultimate in signal transparency. A fully defeatable tube (valve) stage adds incredible versatility to the Cu interface, allowing users to add variable saturation to input signals.

– Tube Stage design by soldano

The rear of the unit provides a full range of professional inputs and outputs in all popular audio formats. Computer interface is handled with the ‘future proof’ USB Type-C, while word clock and digital I/O allows seamless integration with any system or use as a stand-alone.

Add the ultimate I/O path to any system.

Copper Reference Gallery

Copper Reference Gallery

A True 'Hot Rod' Design

Encased in solid copper and hand-made in Seattle, WA, the Cu is a true “hot rod” among premium audio interfaces. Through exhaustive builds and testing, its precise combination of components, layout, firmware and features have resulted in a design that pushes theoretical limits. The added flexibility of the defeatable tube stage provides an extra surge of inspiration when searching for that ideal sound.

Engage The Flow

Copper Reference employs a simple, straightforward signal flow utilizing the finest components available. Features include:

  • 2 Channel extremely high fidelity audio interface
  • 2 mic/line inputs featuring THaT Semiconductor 5171 chips
  • Monitor source Analog, AES, SPDIF or USB
  • Extremely accurate, custom grown TCXO Fox Crystals, Word Clock I/O and digital synch
  • USB Type C with XMOS 8 core processor and universal driver
  • Headphone output with zero latency monitor mix
  • Volume bypass for integration with professional monitor controllers
  • ESS 9038 Pro Sabre DAC
  • 2x AKM AK4396 ADC (summing quad to stereo for increased dynamic range)
  • Mike Soldano designed 12AX7 tube stage for analog inputs with hard bypass
  • Pristine DSP controlled audio signal path
  • Custom product Pelican Case
A Wealth of Components

Having already pointed out many of the top quality components that comprise the Cu interface, one in particular held up production for several months as we waited for availability. We designed the Copper Reference to be the first product to feature the new Sabre Pro 9038 DAC chip from our friends at ESS Technologies. Capable of 140dB DNR and -122 THD, the Sabre Pro embodies the phrase ‘exotic silicon’ and is a major improvement on the previous king of converters, the ESS Technologies’ Sabre Reference DAC.

Not to be overshadowed by the staggering specifications of the DAC, the Copper Reference input path features dual flagship AKM ADC’s run in parallel and summed to gain an extra 3 dB of dynamic range.

No Compromise

From conception, there was never anything ‘mass production’ about the Copper Reference. We have strong relationships with manufacturers of popular mass market interfaces and did not want to compete in that space. So, we took the opportunity to specify, design and build what we considered to be our ultimate audio I/O device.

With no consideration for retail pricing, market position or mass appeal, we designed the product we wanted for our own use. Components were chosen based on performance and compatibility alone. The physical design was intended to be unique and the crazy tube saturation circuit – designed by guitar amplifier legend, Michael Soldano – was added just becuase we thought it would be cool. And it is.

With the promise of working on a ‘no compromise’ product, we assembled a highly experienced hardware design team from top Seattle-based manufacturers and began a five-year project to fulfill our dream. After many iterations, the Copper Reference (aka ‘Cu’) interface is finally available for purchase. We will only build about 300 of these beauties so be sure to order yours soon!

(Image: An early Cu Team meeting at a local pub. L-R James Woodburn, Jan Hofland, and Jamie Wojcik. Nathan O’Neill is missing and Dave Christenson is behind the camera.)

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System Requirements

Class Compliant

ASIO driver provided

Class Compliant

Copper Reference Gallery

Copper Reference Gallery

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