There is a hiss in my Digitakt line input which is audible in the tail end of the samples. All inputs and outputs muted on the 12T yet the hiss remains. No such noise from my analog mixers to Digitakt using the same cables (TRS to TRS).
I’ve confirmed the hiss is present on all outputs of the 12T even when they are muted.
The residual output noise of the CQ is -88dBu (https://www.allen-heath.com/content/uploads/2023/10/CQ-12T-Tech-Datasheet.pdf#page=4&zoom=auto,-274,664) so if it’s more than this then it could suggest an issue with the unit or setup.
Looking at the spec of the Digitakt, it has unbalanced inputs. It shouldn’t make any difference to connect the balanced outputs of the CQ to these, but perhaps try an unbalanced cable (which will just short the -signal to earth at the CQ-12T TRS outputs).
You should also ensure you have good gain staging and a healthy level at the output, better to have a strong (but clean) signal at the CQ output that is attenuated at the Digitakt to improve the signal to noise ratio.
TS cables made no difference. It’s not a gain staging issue since I can clearly hear the noise via HP out with all channels muted (and compare with my analog mixers). I’ll return the unit.