Audio Research EC-21 Active 2-Way Tube Crossover - Serviced

General:The EC-21 is a 2-way crossover from Audio Research designed to optimize bi-wire configurations.It sounded great in our testing and features a tube design with matching McIntosh branded JJ 12AX7 tubes installed inside. This particular EC-21 was serviced here at SkyFi to work reliably for many more years to come. From the original Audio Research marketing materials:The EC-21 is an infinitely variable, fixed frequency and slope, two-way electronic crossover, allowing biamplification of a number of quality loudspeaker systems. Biamplification greatly improves the dynamic range of an audio system while greatly reducing dynamic distortion. Biamplification is the best approach to increasing system performance and efficiency.SkyFi Cosmetic Notes:Light wear is present on all surfaces. The original feet are still in place but have significant wear.SkyFi Technical Notes:This crossover was just serviced here at SkyFi. We replaced the majority of the power supply capacitors, along with the