VGA -> DVI/HDMI adapters

category: general [glöplog]
The question about which adapter to choose for converting strange oldskool video signals into something projectors can grok has been brought up several times in the context of demoparties; This question is a bit more specific to home use.
I've recently had to replace my screen and the new one only has DVI-D, HDMI and DisplayPort inputs, so your standard passive VGA -> DVI adapter no longer works. I already use DisplayPort for my main machine so I'm looking into an active VGA -> DVI or HDMI converter that I can use with my Win9x era retro machines (so video signals shouldn't be too weird).
Something like OSSC seems like a complete overkill for my use case, so I wonder if any of you have recommendations for active adapters that just do VGA. I've seen some from Manhattan, StarTech and Aten, but before I go and buy random junk I'd be interested in hearing some opinions from people who have actually used such adapters with their retro hardware.
You are right, (most of) these adapters are junk. But well, for that price these have, what do you expect?

And don't even expect problems with the 1024x768 Windows desktop, but 320x200 demos, weird textmodes, Mode-X or 400x300 VESA stuff, or similar. :) Even if passing through these to HDMI works, who knows what a modern monitor will say about these weird signals over HDMI. And lets not even talk about the latency or scaling quality (if applicable) of some of these... I have a few of these, but I can't even remember which pile I've thrown them into after buying and trying out once...

My weapon of choice at this point is the Extron DSC 301 HD, which is very expensive new, as it's a pro-grade scaler, but on eBay you can score one between the 100-150 EUR mark, if you're patient. I've bought four of them at this point (two of them were imported from the US though). Their RGB input (over a 15pin VGA D-SUB) is proven to work extremely well with Amiga, with Ataris and with late-90s retro PCs, they have low latency, can skip framerate conversion (follow the input framerate 1:1), etc, all the bells & whistles. So yeah. If you use these kind of machines a lot, do yourself a favor, and get one of these. Additionally, you also get a CVBS input for more weird retro gadgets, YpPbPr for consoles and everything is just seamlessly scaled to full HD over HDMI, no fuzz, no problems. They also have a HDMI input, so you can even scale your 720p console to full HD, or a DVI-D out of an older PC to full HD.

Also, maybe it wasn't your usecase so far, but say, if you want to make recordings of your old systems, it's also quite useful, as HDMI recording devices these days are quite affordable, but even more picky about HDMI signals sticking to a subset of very specific resolutions than monitors... Plus of course they're super useful at parties to connect anything to a HDMI beamer/streaming foo (yeah, streaming, as they also do can do audio embedding, of course). I've used them on this year's Revision for Amiga (and for a few other recordings, like some Games), previously Deadline and Function also used these for hooking up retro gear. I heard the Assembly party team also uses these (among a few other gadgets)...

(Here is a silly recording example. This demo - Spice by Power Rangers, obviously a fake, don't ask why this... - runs in 400x300, and the Extron handled it flawlessly.)

BTW, regarding the OSSC, I'm not sure I'd pick an OSSC for retro PC to be honest. It's more tuned for consoles or anything with a PAL-NTSC/component signal, and scanline-multiplication of these, rather than serving just as digital pass-through for a retro PC.

My 2 cents. I know it's not what you wanted to hear, but yeah. Good solutions, which I can recommend with good conscience are expensive. Also disclaimer here, if someone knows a cheapo adapter which works just to convert input for a monitor (including one which works well with weird old PC modes), feel free to advise, as I'd also buy a few, but so far, I had no luck...

Option B, if you only want a monitor, is of course to buy an old 4:3 17" TFT monitor with VGA input... for ~25 EUR. I've have a few of those too. :D Even that I can recommend more than these cheap adapters from Am*zon (or other places).
added on the 2019-07-12 14:28:24 by Charlie Charlie
Thanks for the advice - it's pretty much what I expected, and now I have a product name to look out for. Seems like there are currently some of them on ebay for around the price you mentioned with shipping from the US, so it might be viable. Putting up another screen isn't really, that's why I'm looking for a coverter/adapater. :)
Actually if you really do not need CVBS or HDMI inputs, Extron has a cheaper (and a few years older) scaler called RGB HDMI 300 A, this is specifically for VGA and RGB/component scaling. It also has a DVI out version.

These seem to go even cheaper on eBay, and just by looking at the specs, it looks like it has similar capabilities to the more versatile DSC 301 HD when it comes to analog RGB. But I have no first hand experience with it, so can't testify if it indeed works similarly well.
added on the 2019-07-12 21:37:05 by Charlie Charlie
I think I will go for the RGB-HDMI 300 A for now and update this thread accordingly. :)
first, DO NOT USE native DVI on videocards (applicable for GF3/4 and Radeon 8/9xxx and later) for DOS stuff, they're just rescaling every VGA/VESA mode to your native display resolution (which is also usually 60hz), thus screwing up/slowing down vblank-syncronized apps, breaking non-standard/obscure resolutions and ratser tricks, etc etc... charlie already wrote about scaling solutions earlier, so take a look ;)

of course to buy an old 4:3 17" TFT monitor with VGA input... for ~25 EUR. I've have a few of those too. :D

well...most of them are actually 5:4, leading to ugly vertical stretching, making most DOS games even more annoying :D
15" 1024x768 LCDs are the suitable choice for DOS/early Windows stuff box, they're compact and dirt cheap, but often coming up with burnt out backlight/scratched/poor response time panels; make sure you've tested them before buying ;)
added on the 2019-07-15 20:01:50 by wbc\\bz7 wbc\\bz7
No worries, those cards pre-date the DVI age ;)
(which is precisely why I'm having this problem)
Ligawo AV 8 in 1 - anyone? I have been doing quite alot VHS and other low-end signal capturing (with some pretty crappy hardware blob) and i am looking to upgrade. But the Extron recommendations (which look pretty serious, though) seem to lack some USB connectivity and there is no S-VHS IN?
added on the 2019-07-16 02:47:56 by wertstahl wertstahl
This isn't a good solution for everyday use, but if you ever find a demo that has some ultra-wacky mode (like 320x200 54Hz, or 320x600 120 Hz), the Sony DSC-1024 can scan-convert them. It does this via blending, so it's not ideal, but it always works and is better than no signal at all.
added on the 2019-07-16 07:14:03 by trixter trixter
USB connectivity? You can remote control the Extron via USB (using some PC app and/or a documented serial protocol, it has even more settings this way than in the OSD), but it's not a capture device, so you won't be able to pull out picture data from it, if you mean that. I use an Elgato Game Capture HD60 when I need to capture these days, works perfectly with the Extron. There's also no SVideo input indeed, which is my only pain point with it really - there are solutions for this tho, and it has a very "decent" quality on CVBS actually. It's still CVBS of course, no wonders, but a really good one for that. This thread is about RGB tho'. ;)

Yeah, the Sony DSC-1024 is really a Swiss army knife and was THE go-to device for scan converting for quite long, I also have one, but it really starts to show its age... Plus of course it's VGA out. I wonder what wacky demos you mean. Any example? I'd test with the Extron. :)
added on the 2019-07-16 13:39:52 by Charlie Charlie
okay, i see, capturing was not part of the usecase. and yes @ rgb, sorry for the little hijacking ;-) [for some reason i was actually thinking convert+capture in one go, but this thread is about (standalone) conversion only!]
added on the 2019-07-16 16:21:46 by wertstahl wertstahl
Got a pair of RGB-HDMI 300 As shipping from the US now (plus a fitting PSU coming from Germany). Missed a single one from the UK for a similar price but now I can just resell the other one. :D I'll know more in about two weeks time. :)
Alright, this took longer than expected... The first package that I got didn't contain the RGB-HDMI 300s but instead two wideband RGB amplifier distributors (Extron DA2 RGBHV) - I know it's a long shot since most of the signal chain is digital these days, but is this something that some demoparty organizers here could find useful, e.g. to split analog RGBHV signals before scan conversion? It takes a number of different input types so I can imagine it would be compatible with quite some oldskool hardware.

It took a while until the seller sent another package.. I guess because he already shipped the actual units I wanted to someone else and now he had to dig something up from his pile of used hardware... because what I got this time was still not what the eBay auction listed, it's just one RGB-HDMI 300 A and 6 Extron power supplies (with cut cables)... so if anyone happens to need a power supply for these Extron devices, let me know... I'm going to stop complaining to the seller now because I got at least one working unit.

Anyway, the picture quality is good and there are lots of customization options. Sadly I couldn't find any setting that would allow me to automatically preserve the aspect ratio, but I can configure a preset to scale everything to 1600x1200 and then output as 1920x1200. Maybe there is an easier way that I'm not aware of yet.
@charlie: could you get in contact with me regarding your experiences regarding settings on the Extron DSC 301? I'm planning on using this for TRSAC, and having first hand experience from you would be much appreciated.

I/we can be contacted via: trsac [at-sign] trsac [dååt] dk
added on the 2019-09-19 12:49:33 by Puryx Puryx
@Saga Musix: Yeah, the aspect ratio is a bit of a problem, I normally work this around by setting the output to something 4:3, then just set "fill" not "follow" in the menu. Until the refresh rate is stable and something standard, the equipment I use is less picky about it. So this works well for my use case. But again, the RGB-HDMI 300 menu could be something very different to the DSC 301 HD menu, I didn't check. Maybe I should. :P

@Puryx: Mail sent.
added on the 2019-09-20 01:03:50 by Charlie Charlie