exxos's Atari, Amiga & retro forum

I installed the STE DAC upgrade board (v0.2) from the Exxos Store into my STE and I'm very happy with the result!

The STE originally had horrible signal quality (lots of signals from the motherboard leaking through) and now it's so much better!

I also replaced the two caps to the left of the board with versions with longer legs so I could bend them down because I saw the PSU was slightly elevated due to their heights. Strange, I can't imagine that the original design was like that but they looked original nonetheless.

What a brilliant result, well done on a great installation!

:bravo:

I think your probably the only one which has fitted one so far!

Would love one, but my STE is NTSC...

:(

exxos wrote: 01 Oct 2025 22:49 :bravo:

I think your probably the only one which has fitted one so far!

:WTF:

Amy idea why? Maybe the 'prototype' moniker puts people off?

It really wasn't that hard to do. Even soldering the DAC onto the PCB was perfectly doable with just a soldering iron and no soldering paste.

sandord wrote: 02 Oct 2025 08:13 :WTF:
Amy idea why? Maybe the 'prototype' moniker puts people off?
It really wasn't that hard to do. Even soldering the DAC onto the PCB was perfectly doable with just a soldering iron and no soldering paste.

No idea. Nothing much really sells at all in atari land. I mean people been moaning about video quality for years, I come up with improvements and nobody is interested. Same when I was developing a scart addon to help reduce signal noise. Nobody would buy it so I didn't bother with it.

I had the same DAC kit for the STFM and somehow most people ended up making things worse. Trying to figure out such problems is just a neverending grind. Just not worth the time and effort just for like 5 boards which sold. It's part why I'm discontinuing a lot of stuff. Said it all before anyway...
viewtopic.php?t=7623

But glad someone had good results for once :thumbup: I think it's a really cool add-on.

Hmm, after testing a bit more, I noticed that I need to crank up the gain and levels of my OSSC all the way up to get somewhat acceptable signal levels. The monitor itself is definitely set up bright enough because the OSSC overlay menu looks very bright.

This is when testing with the GEM desktop.

When I start a game or a non-GEM program like Dpaint, everything looks even darker. Could this be due to the extra DAC bit the STE has (4 vs 3)? I imagine that GEM sets it in the default palette but non-GEM programs that are unaware of the STE don't... Although this shouldn't make that much of a difference since it is the least-significant bit.

Afraid I don't know anything about OSSC or scan converters as I don't use them.

Everything works fine with scart on low and medium res for me. It's the same DAC as used on the H5 and Falcon.

I did some quick tests. On my monitor, the brightness is actually turned down a bit and its still bright.


Are you sure you don't actually have the reverse problem.. because like with my monitor, if the brightness is to bright , it actually goes really dark.. You may need some series resistors for your scan converter to lower the voltage if it's that fussy.

Or the OSSC doesn't have 75R termination resistors on its inputs?

I have noticed that when connecting a CRT (1084S), the picture of the STE with the DAC board seems about a third as bright as that of my other STE.

So I think we can leave the OSSC out of the equation.