No operational issues. The SQ1G is the latest evolution in a design refinement process that dates back over 40 years to the earliest Klark Teknik graphic equalizers. Enhanced proportional Q response replicates the response of the classic single-channel DN27 graphic equalizer, using modern solid-state design and manufacturing techniques. The SQ1G also features dual-channel 30-band graphic equalization with fixed high-pass and low-pass filters per channel. The SQ1G provides essential features for corrective equalization and filtering in a cost-effective package without sacrificing audio performance, making it ideal for both FOH and stage monitoring applications. Gentle contouring and precise high-Q notching, uniquely enabled by the proportional Q response, improve clarity and eliminate subsonic rumble, room and speaker resonances, and standing waves. Please check the photos for the condition before purchasing.