Skip to main content


process product detail

All OMA products are made in the immediate environs of Oswald's Mill in Eastern Pennsylvania. Most are made by hand, though sometimes aided by very high tech engineering. To understand what we make, it's useful to know the processes involved.

Our slate, from which our turntables, plinths, equipment racks and even some amplifiers are fashioned, comes from the last two functioning quarries in Pennsylvania. It is cut on a state of the art five axis water jet machine owned and operated by a Mennonite family, surrounded by Mennonite farms. Once cut, the slate is honed by hand using water and diamond tooling and abrasives.

Our foundry has been owned and run by the same family for four generations. It specializes in cast iron and bronze, the most ancient metals. Working closely with the foundry master, our new products such as the Ironic cast iron loudspeaker employ cutting edge fabrication technologies, such as 3D printing the sand molds used to cast the Ironic, and using special hypo eutectic high graphite grey iron for its non resonant, anti vibration characteristics. The bronze throat castings for our AC1 loudspeaker demonstrate the foundry's long history producing exquisite architectural details.

Our hardwoods (black walnut, cherry and ash) grow in the surrounding forests and are sustainably harvested. They require two years of air and kiln drying, usually in solar kilns which gently heat in the day, and cool at night, allowing the wood to release tension and provide more stable lumber, critical for our loudspeakers. We buy our wood in the form of "boules", an entire tree slab cut so that every board will match in color and figuration.

Once the wood has been properly conditioned, our master woodworkers build our loudspeakers, amplifier chassis and other components by hand, the old fashioned way. This takes far more time, is more expensive, and ensures a superior product.