At Coffman Labs, we use a liquid-nitrogen (LN2) cryogenic process to treat selected conductors and components used in our products.
Cryogenic treatment is a materials process that exposes a material to extremely low temperatures and then returns it to normal operating conditions. Liquid nitrogen reaches approximately −320°F (−196°C), allowing materials to be exposed to temperatures far below those encountered in conventional manufacturing or normal operation.
The process is particularly interesting at the microscopic level.
What happens to the material?
Metals have a crystalline structure made up of grains, grain boundaries, dislocations, and other microscopic features. Manufacturing processes such as drawing, forming, machining, and plating can introduce stresses and changes within that structure.
When a metal is cooled to cryogenic temperatures, it contracts. Because the material is not perfectly uniform at the microscopic level, different regions can respond differently to that change in temperature.
Research on copper and copper alloys has shown that cryogenic treatment can alter characteristics such as residual stress, dislocation structures, grain boundaries, and precipitation behavior. The specific effects depend on the composition of the material and the treatment process.
The material doesn't simply become "frozen." Its microscopic structure is responding to a significant change in temperature.
Why does that matter for audio?
An audio signal travels through a physical electrical system. Conductors, connectors, solder joints, transformers, switches, and other components all contribute to that system.
Changes at the material level can influence the electrical and mechanical behavior of those components. In an audio system, those changes become part of the signal path.
At Coffman, we've found that cryogenic treatment makes an audible difference.
What we hear isn't a new sonic character or an exaggerated effect. The difference is in the qualities that matter most when listening closely: greater clarity, improved resolution, more precise spatial information, better separation, and a more natural presentation of dynamics and tone.
Low-level information becomes easier to follow. Individual instruments and voices have greater definition within the soundstage, while the overall presentation remains coherent and natural.
The goal isn't to make the system sound different for the sake of sounding different.
It's to preserve more of what is already in the recording.
Why LN2?
The term "cryo" is used to describe a range of different processes, and they can involve substantially different temperatures and methods.
Liquid nitrogen reaches approximately −320°F (−196°C), placing it firmly in the deep-cryogenic range.
That extreme temperature is significant because the effects of cryogenic treatment occur at the material level. For copper and copper alloys, research has documented changes in microstructure, residual stress, dislocation structures, and other material characteristics following cryogenic treatment.
For us, LN2 provides a consistent way to apply that treatment to the materials that become part of the signal path.
A labor-intensive process
Cryogenic treatment is not a quick or automated step.
It requires careful handling of the materials before and after treatment, along with the equipment and procedures necessary to work safely with liquid nitrogen. At Coffman, selected conductors and components are treated individually before they are incorporated into the finished product.
It adds another layer of hands-on work to an already hands-on manufacturing process.
For a company that builds its products by hand, that's a meaningful consideration. But the treatment has become part of how we prepare the materials used in our products.
Cryogenic treatment is material-specific
There isn't a single response to cryogenic treatment.
Copper, steel, aluminum, and different alloys have different structures and can respond differently to changes in temperature. Even within the same material category, composition and manufacturing history can affect the result.
That makes cryogenic treatment a materials question rather than simply a temperature question.
It also means that the treatment needs to be considered alongside the material itself. At Coffman, selected conductors and components are treated before being incorporated into the finished product.
Part of the construction process
Cryogenic treatment is one step within a much larger manufacturing process.
The materials we select, the conductors we use, the connectors and solder, the transformers, the insulation, and our point-to-point construction all contribute to the final result.
Cryo doesn't replace any of those things. It is part of how we prepare the materials before they become part of the finished circuit.
Most of this work disappears once the product is assembled.
The wire is inside. The connections are covered. The microscopic structure of the material is invisible.
But you can hear the cumulative effect of the decisions made throughout the signal path.
The process happens at the microscopic level. The difference is heard in the music.