Hey there. Just to be clear, you're asking for your 64 channel mixer to be able to handle 64 stereo instruments? Even in the digital world, computers have limited processing power. A stereo signal is processed as two separate signals, with different audio content, origins, and destinations. That's the nature of stereo. A 16 channel presonus mixer has a single processing core. A 32 channel mixer has dual core. A mixer capable of 64 stereo channels would need 128 channels of processing, or 8 cores. And unless half the channels were only available digitally, it would also need double the number of phisical inputs and preamps, which would drive the price up substantially. At that point you're buying a 128 channel mixer, but with only half the faders.
