Ran out of time last weekend, but I finally got around to doing the MCU firmware update today. The faint ticking that I was hearing during very soft passages with DSD playback is gone. Definitely worth the effort. The instructions provided by Gustard were pretty good. If you decide to take this on, in addition to a Windows computer and the STC tool I mentioned
here, you'll need 2mm and 2.5mm hex keys:
Also, a 5mm socket driver:
I removed the four screws in the corners using the 2mm hex key. I then removed the pairs of screws holding the XLR jacks in place and the remaining screws next to the RCA jacks.
The back was pretty easy to pull off. I just tugged on the BT antenna socket a bit. It only needs to slide back an inch or so to allow access to the brass nuts. The 5mm socket driver was up next to remove those from the ends of the threaded rods that hold the display in place.
With those free, the front panel pulled off easily. Just a slight tug.
Again, just had to pull this out about an inch so that I could unscrew the threaded rods from the corners of the display. The display is surprisingly heavy, so don't let it fall. I set a microfiber towel down to lay it flat without getting it scuffed up.
The ribbon cable connected to the display, as we've seen earlier in this thread is a bit fragile. There's a stiff plastic bit covering the part that slides into the back of the display. And, a little of that sticks out. I grasped both sides as close as I could to the green plastic and pulled with equal force until the ribbon cable came loose. Easy does it.
It's important to match the 5V pin into the J3 socket:
Gustard's instructions for installing the USB driver for the STC tool and getting things connected worked as advertised. It was interesting to see the detached display wake up after connecting the tool:
The rest of the software instructions worked fine as well. Resist the temptation to download the update for the STC tool. Not necessary, and it added a few minutes to the process.
The firmware version did not seem to change after I did the update, but I definitely had clicking sounds during DSD playback before the update, and they are definitely gone now, so I'm happy.
Assembly process was just everything in reverse. I made sure to return the two yellow ground wires next to the power inlet back to the rods on the right. The screws that hold the XLR and RCA jacks are going into plastic, so I had to take care not to strip them. I turned them counter-clockwise until I felt the threads line up, and then gently screwed them back in. Everything during reassembly should be finger tight.
I've shared this earlier, but all of the files and instructions that I used are zipped up here:
Gustard_X16_MCU_Update.zip
Many thanks to
@shwnwllms for sharing tips along the way. If you don't already have the required hex keys and socket driver, this set comes highly recommended:
https://www.amazon.com/gp/product/B07ZD3WSL4/
Good luck! Now, back to listening…