As the manufacturer of Signature , we are proud of getting Amir recommendation based on test data. We think that Signature will outperform (jitter and noise floor) all transporters on the market at any price point (BNC where you can see the real performance)
Now , test data , clearly shows that THD+N numbers with a good dac (with good jitter reduction) will not change with a poor/good digital source. On the other hand , you have multiple subjective opinions that a better source produce a better sound (I want to stress that no test data shows it)
Whatever camp you are in...we designed the Digione and especially the Digione Signature to have very low jitter. We go to great lengths to filter every rail , to think about every detail , to give you a digital output thats so clean , different cables will slightly change it. We are (decent we think) engineers , but in the end, we just love music , like everyone here.
Final decision is , of course , with each customer . Enjoy