NOS vs. Digital Filtering DACs: Exploring filtering turned off, implications, fidelity and subjective audibility. (Recent BorderPatrol DAC chatter...)

Hmmm... Non-OverSampled waveforms - "accurate", "high fidelity"? The waveforms above were captured with my RME ADI-2 Pro FS ADC at 384kHz. As you can see, each waveform originated either from the TEAC UD-501 DAC with the digital filter turned off (Non-OverSampling - NOS mode) or with the TEAC's "Sharp" oversampling filter turned on. On the right, we see the same waveforms captured from an