Streaming a DSD256 file to a DAC capable of DSD128, but not DSD256 shows a DSD to DSD conversion in the signal path.
What kind of conversion algorithm is being used in this case? Is this a direct DSD to DSD conversion, or is there an intermediate PCM step (DSD - PCM - DSD)?
A true DSD to DSD conversion does not exist. Once DSP is applied, single bit word length has inadequate resolution, thus is converted to floating point multi bit word length. Subsequently, that multi bit is fed back into a sigma delta modulator to convert back to single bit.