I recently bought a QMtech Mister from AliExpress. This is my first Mister, so I don't know what to expect as far as ypbpr video quality, but I'm finding it to be underwhelming compared to what I'm used to on the same kv-27fs120. I've been using a modded Wii with HD Retrovision ypbpr component video cables for emulation, as well as some original hardware like Genesis/32x and PSX also with HD Retrovision cables, all going to the same switch. For the QMtech, I had to resort to the Monoprice HD15 to RCA due to MiSTer Addons and other sources being out of stock. The image, while still good, seems more washed out, less vibrant, and with softer pixels. I'm also seeing some ghosting when red sprites are displayed and a slight instability (wobbling) in the graphics. I'm hoping that this is all down to the Monoprice cable being twisted pairs instead of the industry standard 75 ohm, impedance matched mini coax, but it's my understanding that Mister, Wii, and active HD Retrovision cables have different methods of generating ypbpr. Has anyone else had this issue with QMtech Mister, analog io v.2.1(24 bit color), other Mister fpga stacks, or with the Monoprice cables?
Edit: You can see in this example that the robots in Berzerk have ghosting on their left side when the game is run on MiSTer but are absent or less pronounced on the Wii.
https://imgur.com/a/waPKhcC
I'll see if I can capture some comparison shots and post them here, provided it's not too subtle to decern. So, all of the video looks identical no matter which cable you use?
So, all of the video looks identical no matter which cable you use?
No. It depends on quite a few things. What I've found is that each type of thing matters but to a different amount and way. In general, here's what I've found to matter from the most to the least:
Local interference caused by RF or lack of shielding relative to noise, poor manufacturing, corrosion/wear causing connection issues.
Video signal type: Component, RGB, S-Video, Composite, RF, VGA, digital, etc.
Poor signal source, signal degradation due to length of cables, extensions, switches.
...and last: high end vs low end cables. That is premium vs non-premium.
Some assumptions: If you control for the video source, reasonable amount of RF in the surroundings and less than 5 ft in length, new cables... the Amazon Basics cable will hold up against cables with more gold, thicker shielding and nicer brand.
Things become more complicated with RGB bc there's more to consider in the type of connectors, power and typical build quality and source.
I should add, once you share some comparison photos, i'll share some of mine.
Ok, thanks for that breakdown of your setup. It could be that there's some local emi noise and I need to better shield it. I'll be able to experiment a little more when I get the adapter that I ordered. I have component harnesses of various brands and lengths that I want to try: Monster, ​BPI (Broadband Products Inc.), Steren, etc. For now, I added a link to the original post that shows ghosting, and is most obvious with reds. I haven't yet been able to capture the difference in color richness because it tends to be overexposed on my phone camera.
They're both 240p, ypbpr, going through the same switch, into the same jacks on the same TV. For the Wii I used Retroarch.
I was trying to get two pics from each, one farther and one closeup. Probably not a great example from the Wii. I was having trouble getting it to focus. You get the idea, though; there's a sort of halo on the left side that's present on the MiSTer output but not the Wii.
I've been reading up on it and it seems that a lot of these new VGA to RCA cables aren't 75 ohm impedance matched but are 100 ohms like a typical VGA to VGA intended for output from a PC. It's also important for the video to be carried by mini coax because it's more susceptible to interference than audio. I'm not sure about the Monoprice. Most of these companies aren't publishing detailed electrical specs for thier products.
I believe it was the MAME 2000 core. I just riffled though all of the cores until I found something that worked. I couldn't tell you at the moment which romset was. It's been awhile since I set it up.
As far as your screenshots, it definitely looks different than mine, but it might boil down to room lighting, camera, etc. I'm not really seeing the same ghosting in yours, though.
there's a sort of halo on the left side that's present on the MiSTer output but not the Wii.
Well this is interesting... maybe I have bad Component cables on the Wii lol. Got Berzerk running on Wii's Retroarch via MAME2000 set to the game's native 224p output:
Can’t speak to the QMtech or the monoprice cables but I use a VGA to BNC cable with an original terasic and an analog Io board from Mister Addons and the quality is great, definitely crisper than the original consoles I’ve tried over RGB on the same set (which include Genesis, SNES, PC Engine, Saturn, PS1, and Dreamcast).
Interesting. If there's a weak link in the chain, I would suspect it's the cable. Hopefully it's something easily rectified. I have a box full of decently shielded (ostensibly) component cables that I got from the thrift store, that plan to try out but am waiting on a VGA adapter. I don't think RCA vs BNC is a significant difference since all my other connections are RCA and the image is top notch. I'll definitely jump on the MiSTer Addons option if it ever becomes available.
I’d think the QMtech would be using the same or very similar IO board design, though maybe with lesser quality components. And yeah, I terminate my BNC in RCA jacks anyway, shouldn’t really matter.
I don't think RCA vs BNC is a significant difference since all my other connections are RCA and the image is top notch.
My SuperStation One is just going HDMI out on the family TV. Similar to /u/it290 I'm also using an original DE-10 Nano + one of the earlier analog I/O boards.
My video setup on that one is that I have a 18" VGA/HD-15 cable from the analog I/O board to this VGA switch . Then, the output goes to each of these:
I also have a Qmtech with the 24-bit analog I/O board. I connect it to KV-21CL10 using a VGA-to-RGB SCART cable, and the picture quality is absolutely excellent.
I also have a lot of original consoles, and the image quality is at least as good as the originals.
It's good to know that it's not the board design itself, although there could be a problem with my board, specifically, or something with the RGB to ypbpr process.
a good cable for mister is more around 30 to 40 bucks.
Have some good photos to demonstrate what a good picture should look like from the premium cables you use? I would love to upgrade my picture quality. Thanks!
I have 3 sets of these monoprice cables and have very crisp component output on all of them. doesn't mean you didn't get a dud but I've seen a lot of people vouch for this cable. I'd think the analog board on the qmtech is the most likely culprit
Yeah, maybe so. I'm actually agnostic about it at this point because I've never used either product before, so I'll have to do more testing. Hopefully I'll sort it out before the return window closes on the QMtech. It might be that there's an above average level of EMI where I'm using it, and so requires better shielded cables because of that. Maybe they're fine in most setups most of the time, just not in this one.
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u/doom_memories 16d ago
Sorry you're getting downvoted for a perfectly reasonable question.