On the subject of the DAC used, and why it was 'only' 12 bit. I believe the instrument actually runs all of the voices through a single DAC, so it is basically

On the subject of the DAC used, and why it was 'only' 12 bit. I believe the instrument actually runs all of the voices through a single DAC, so it is basically 16x oversampled, and the voices are held by a sample and hold circuit for all 16 voices before they are summed to the analog output. If the later DX mark II is anything like the TX81z (which is also said to have a 16 bit DAC) it actually uses a 16 bit dynamic range DAC, but with a 10 bit resolution (a YM3012 for the TX - https://www.alldatasheet.com/datasheet-pdf/pdf/1179489/YAMAHA/YM3012.html https://www.alldatasheet.com/datasheet-pdf/pdf/1179489/YAMAH...) This is definitely the age of interesting DACs, with all sorts of interesting noise profiles. We're really spoilt these days with the quality from delta/sigma DACs, thinking that this has always been the case!