With the SCSP EG in pretty good shape, I have turned to fix some of the remaining issues in the DSP. The main fix I put in was support for the input effect mixer which fixes many of the dry/wet balance issues. I put in floating point support as well for ring-buffer read/writes. This fixes popping issues when the DSP initially reads from the ring-buffer, which most driver versions initialize to 0x6000 (the DSP floating-point representation of zero).
I also noticed that the EG_Update() function can possibly return a negative value in the DECAY1 state, which would potentially cause a segfault when later used as an index for table lookup (and if it doesn't, the output from it would probably sound very bad). I fixed this by adding a clamp to zero in the DECAY1 state.
I also took a brief look at LFO code and noticed that the saw PLFO was mistakenly set to a triangle waveform, so I fixed that too.