I was just mucking around with an oscillating filter being routed through the ER-301 and was rather surprised by the degree of aliasing artifacts being produced. I thought perhaps my filter was acting up, so I recorded some sweeps to get to the bottom of it:
The first sweep is direct and the second is being routed through an empty chain. The input level was moderate, so I don’t think the anti-aliasing filters are clipping. And the built-in sine oscillator does not exhibit any aliasing that is noticeable to me. The effect is more pronounced with the 48kHz firmware, but is also present with the 96kHz version.
I understand that the inputs are being resampled from 60kHz to the target rate. Is it maybe possible to run the IO at the ‘host’ rate to avoid resampling? Or maybe an option to run at 60kHz?