I'll be doing some listening comparisons between the Gustard X16 and the iFi Audio NEO iDSD. I'm more familiar with the sound of the iFi since I've had it in the rack for a few months. It's the best sounding DAC I've had in my system, so it will be interesting to see how the X16 fairs.
One thing I really appreciate about the iFi is that everything works. Want full MQA decoding and DSD over S/PDIF? Sure, no problem. Want to thrash your amp with up to 7.7 volts of output? Check. Need a serviceable headphone amp? The NEO has one. Short on desk space? The NEO's display rotates when you set it in its vertical stand.
The iFi is a $200 more, but it's also a more complete product. For example, I was surprised to find in the X16 manual that MQA decoding is not supported on the S/PDIF inputs. I don't care much about MQA, but since MQA decoding is implemented inside the ESS ES9068S chip itself, I don't understand the reason for this limitation. But I do appreciate the heft and solid feel of the Gustard.
I'm hoping that the IR codes from the remote for my Topping Pre90/Ext90 preamp do not conflict with the X16. When I press "volume down" on the Topping remote, the NEO switches to a different input. Pretty annoying. To reduce the volume one click, I have to go down four and up three to cycle back to the same input. LOL. BTW, I have tried driving my amplifiers directly from the NEO, but that did not sound great. Detailed, but lacking dynamics and impact. A bit "grainy" too. Inserting the Pre90 makes a fairly dramatic difference…likely because the input impedance on my monoblocks is rather low.
I've rambled. Happy listening.