SMSL DO300EX AKM Review – AK4499EX DAC & Headphone AMP The ‘EX’ in the name of the new SMSL DO300EX is a reference to the latest EX series DAC chip technology of AKM. For me, the important thing here is not the EX in the name, but the revised flagship DAC chip called 4499EX at the heart of the DAC’s board. The DO300EX incorporates an AK4499EX DAC chip coupled with an AKM AK4191 digital filter interface. This chip combo and … Continue reading SMSL DO300EX AKM Review