I bought this kit a few months back as a pre-order and had to wait since I wanted a different colored shell. But the kit allows you to use a donor GBA mainboard from a standard GBA and essentially turn it into a small console to play your games on a modern big screen display using an SNES controller. Here are thoughts on this:
The small ribbon cable that has to be soldered to the GBA CPU is tricky and requires a lot of patience to get soldered into place. The pitch of the soldering is quite fine and I had to use my 10x loupe to verify the connections and check for and remove any bridges I found (There were quite a few). The ribbon cable is designed and marked to help you line everything up. It has a nice center GND you solder down at the corner of the CPU to help anchor the ribbon in place. There are also markings showing where pin 1 and pin 127 should be lined up. However, the first time I tried this, I actually had the left hand side of the ribbon where pin 127 is one pin off. Due to the way this ribbon is designed it is possible to have one side perfectly lined up but the other side be too high or too low allowing for a 1 pin offset as I had initially. No damage done as it just meant my controls weren't working initially. But it did require me to carefully undo and remove the ribbon completely so I could clean up everything, re-align it and do it again. This picture below is of the final and successful placement of the ribbon on the CPU.
The kit comes with a 3d printed case shell. You can choose from the colors they already have on hand and available if you are in a hurry or you can specify the color you want. I do have to complain about this part because they don't list all the colors in their order page and only stated that with a custom color, you specify. However, there isn't a comment section or anything in which to specify this?! What I did and apparently this worked, was when I made my payment via PayPal for the kit, I specified that I waned a purple case shell if possible otherwise red would be good. But again, they didn't have a list of the colors they can do anywhere so I was guessing they could accommodate my choice. They did as do have a purple case shell for my kit. The fitment of the case was great as it initially arrives already pieced together without the screws in its own bag. However, once everything was assembled I found quite a few issues. For one, the GBA mainboard doesn't line up flush with the edges of the case shell so everything is recessed inward about a 1mm or so. This isn't a huge problem, but it doesn't look as finished as it could. The holes on the inside for screwing everything down into place doesn't allow for any adjustment so it is what it is. I also found that the openings for the ports on the back are a tad on the too small side of things. But since it doesn't sit flush anyway, this doesn't matter that much. It did come with two power buttons I can choose from. A grey solid printed button, or a white semi translucent one. I chose the white hoping it would allow the LED on the GBHD board to shine through. Spoiler...it doesn't.
However, the main GBHD FPGA board does seem to sit more flush with the front side of the case so there is that.
The sticker comes in the kit and is an optional thing you can apply. I sprayed off the top of the case with some 99% IPA to make sure it was a clean surface before applying the sticker on mine. I think I got it lined up pretty well for eyeballing it.
So...what about the output and overall thoughts?
To sum up...it is outstanding! The way the kit works is that the GBA main board is only used to provide the logic for reading the game and handling the controls. The LCD driver on the GBA main board is what is providing the video output to the GBHD FPGA board that provides the final output. As a result, you remove the battery terminals and the speaker off the GBA main board as they are NOT needed and take up additional space. In fact, on some of the other GBA console kits, you have to make sure to put the GBA power switch in the on position, but because of the way this kit work, it is providing voltage directly to the CPU when you power it on. As such, the power switch and volume wheel have no use or function anymore since all of that is bypassed. In fact, the audio comes straight off the CPU pins and is handled by the GBHD board itself. In a nutshell the GBHD FPGA board is really doing the heavy lifting for the video/audio output and as the interface for the controller input on the front. Audio is an issue for some as I've been told it isn't compatible with all setups. This is because the audio appears to be handled as PCM analog through the HDMI and I guess newer TVs and AV receivers don't support that? My AV receiver in the game room is 10 years old and not only does it support PCM audio, but supports up to 96khz PCM so I had NO issues with this on my AV setup.
Once installed, the kit allows you to pull up a simple to use OSD for changing a few things on the video display. It defaults to output at 720p and this is really the most compatible and best looking option as it provides about a 4x scaling from the GBAs original resolution. It has different modes to control the aspect of the image from proper integer scaling (Default) to stretching to fit your widescreen or a setting of in between with a little stretching and some minor borders around the edge. It has an option to compensate for overscan and this was needed on my TV in the lab area but not required on my main TV in the game room. You can also choose what color you want the border to be if you so desire. There are options for LCD grid like effects and scanlines. These look okay but I'm not a fan of either when playing on my big screens. There is also some filters but I honestly think they made the output look worse on my modern TVs. My guess is they are there to help provide a better look if you use this with other equipment to play on a CRT but that is just a guess. My kit came with Firmware v4 pre-loaded and apparently was assembled back in June of this 2022. I do see via where something like a jtag header could be soldered in but do NOT see or know of a way to update the firmware in the future. It might be possible this is something that could be implemented in the future using flash carts? But that is only speculation.
How does it look? Well here is a quick 1min video of it in action with the game Iridion II since I had that handy for testing. I used my phone to get this so it isn't direct capture but you get the idea.