Experiencing noise in the ADCAP's RGB output? Here's what I know and what I did to mitigate it in new builds. You can try these in your build but be advised that any damage done to your unit is your responsibility. You've been properly warned.
I recently changed out PSUs in the ADCAP design with a Meanwell RQ-125. Its showing a better picture, but it doesn't "bolt" into place on the older MK30 cases as its mounting points are all different. I am hesitant to say for sure its the "great final fix" for the older cases as I am not confident I could keep a retrofitted one into place during shipping. I did a Twitch stream showing how I prepped the PSU here: https://www.youtube.com/watch?v=y4pZcoRN6ps&t; I suspect that the handy among us can do this swap in about 20 minutes. Here's the part link on mouser.
A few notes on the troubleshooting with my ADCAP and my PVM.
1. I never noticed any interference on the PVM like some of you have nor on my Arcade Monitor in a box when testing my personal ADCAP (which is built the exact same way as everyone I have built). I only ever really saw some "dancing ants" on the XRGB-Mini and a large flat screen. As to why its varied among everyone, I am unsure but its likely a wide quality control situation with the PSUs. The new PSU didn't really have a huge effect on my PVM that I could tell but on the XRGB Mini it was a noticeable change that improved as the PSU and board warmed up.
2. I suspect that there are a couple points of possible interference that could be had. First the long run to the pots on the front of the ADCAP. Its possible its picking noise up there. The pots are high quality, but the shear run length and loop back could be part of it. The PSU for sure, and the video cables in use to hook everything up. I have a couple video cables I have used that flat out don't work and some that are great.
3. The Suzo Happ PSUs aren't the same quality as they were 4-5 years ago when I started making SuperGuns. First round of ADCAPs didn't have this issue. It seems that the last round of PSUs I received were the in the batch where the decline started. I haven't been using them for as long as some folks have, but I suspect the quality is going down hill by means of them finding cheaper knock off parts to assemble the PSUs to maximize profits and get generally acceptable results for coin-ops who just want things to power up.
4. On the latest builds I finished in December 2017, I did some tests where I connected the outer-ring of the 8 pin mini din to the GND on the ADCAP "brain". I noticed a change there as well; connecting the shield to the ground line seemed to offer an additional reduction in noise on the black "no picture" of the upscaled image.
My general recommendations to improve the experience:
1. Run a ground wire from the shield to the GND on the ADCAP.
2. Upgrade to the RQ-125 PSU.
3. Use high quality shielded video cables.
What I am doing with the SuperGun line up:
The last 5 I finished 26 Dec 2017 are my last. If I do more, I am going to revise a number of things so that I can build them faster and hopefully mitigate some of the noise. To do this I intend on doing the following (or considering it):
1. Remove the PSU from the internal case and move it to be an external brick. This will allow them to be far away and be far easier to replace should they go bad.
2. Remove the JROK from the build completely. More and more people are turning to the OSSC to use their classic and retro stuff on HDTVs, so why waste $80 on something that really isn't necessary.
3. Redesign the internals to integrate the new audio attenuation circuit in use, the main ADCAP board, controller ports, and such into a single PCB. Doing some creative routing of signals, power, and ground planes will remove potential locations of interference pick up most likely.
Find something else that helps?
I am definitely interested in hearing your solutions and what you have done to modify your ADCAP SuperGun. Let me know in the comments below, we can all learn from each other since we all bring a different bit of knowledge to the community.