A video game apparatus includes a CPU. The hinges are mounted to respective plates in the base and top box having sufficient thickness and strength to support the weight of the top box without binding. The processing device is configured to select one of the plurality of gain tables based on the signal strength of the digital input signal and apply one or more values in the selected gain table to the filter, the amplifier, or both, to process the digital input signal, the analog output signal, or both.