I have tried upsampling (max PCM and max PCM power of 2) to both Mojo and 2Qute. I did detect a difference (perhaps a wider stage), but in the end preferred turning DSP off. Enabling DSP, at least on these Chord DACs and in my system, reduced detail and precision.
Per Rob Watts when asked if the Mojo upsamples and if so what does it upsample up to?
“Yes all my DAC’s up-sample to 2048 times that is at least 16 times
more than typical. What does this do? Well its not just about up-
sampling but filtering out the RF noise that is present on a digital
signal. Its essential to do this, as it gets you closer to the original
analogue signal in the ADC (and this is the DAC’s job to recover the
analogue signal not the digital data). This extensive filtering reduces
jitter sensitivity by a factor of 64, and allows the DAC to eliminate
noise floor modulation. Now this is a very important problem, as it
makes the DAC sound hard and less smooth and is a major problem with
DACs - all other DACs have very large noise floor modulation, Mojo has
zero measurable noise floor modulation (I have plots at home proving
this). This is a major reason why Mojo sounds so smooth and natural.”