Apart from a substantial difference in audio emulation accuracy, probably the most obvious difference between the 'plus' and 'non-plus' versions of the core is that the latter has an inadequate level of low pass audio filtering, leading to tinny/scratchy sound.
This PR adds a simple optional low pass filter at the output stage of the 'non-plus' core. When enabled, audio is more mellow/bassy, and the generated sound is closer to that produced by the 'plus' version - with only a negligible increase in performance requirements.
Apart from a substantial difference in audio emulation accuracy, probably the most obvious difference between the 'plus' and 'non-plus' versions of the core is that the latter has an inadequate level of low pass audio filtering, leading to tinny/scratchy sound.
This PR adds a simple optional low pass filter at the output stage of the 'non-plus' core. When enabled, audio is more mellow/bassy, and the generated sound is closer to that produced by the 'plus' version - with only a negligible increase in performance requirements.