In 2010 Audio Research announced the Reference Anniversary preamplifier, a special limited edition product commemorating their 40th anniversary. It was acclaimed by many as the finest preamplifier available and a fitting tribute to all of the classic Audio Research products that were introduced during the forty years that preceded it. That they would only accept new orders for this special product during the anniversary year surprised almost everyone, but they considered the limited time frame appropriate. Since that time, they have learned a few things, and the result of that knowledge led to the development of the Reference 10. Included are critically chosen new components, proprietary custom-made capacitors, wiring, and new connectors that cumulatively provide a level of performance never before achieved. Key Audio Research design traits remain: The signal path is fully discrete, all-tube, pure Class-A, with zero feedback. Other attributes and choices remain, too: Each unit is completely hand-soldered and hand-constructed in our Minnesota facility using the finest materials, with major components such as custom transformers, plated-through circuit boards, and casework sourced locally. All engineering is performed in-house.