Ideally you need two matching sticks, your options are 2x 1MB, 2x 4MB and 2x 16MB. Parity SIMMs will work but are not good to use on these sound cards because the parity lines are not connected and any digital chip with floating inputs can do strange things.
The sticks you got should mix and work though.

Thank you. I have now decided on the only reasonable option: Two exactly the same 2x1MB 70ns parity modules. I have no idea if there's anything you can do with it. I didn't manage to activate the General MIDI emulation. Tried it with SAM & Max just like Phil in the Youtube video. But there was only a freeze. Does this require external RAM? I'll test this again in a few days.

Big setback, the RAM arrived, is also recognized and tested as functional by diagnose, but aweutil no longer works at all, and freezes the system directly. What is that now?

Take a pencil eraser to the ISA connector of the card, this will clean things up and at least rule out one problem. Perhaps try different versions of the Creative drivers, there are a number of versions around.

Hello again,
I have to be a little more specific, sorry. Only the tool aweutil does not work under DOS. The initialization, with /s, works via autoexec.bat. But after that the system hangs at aweutil /? , as with the other commands. But if I had a sound source on, e.g. Doom, it sometimes works to enter commands via aweutil, such as reverb and chorus. The MIDI emulation can also be activated in this way, but it does not work. All very strange. Win 3.11 is also installed on the PC. The completely different awe tool works well there. The RAM is displayed, you can then manipulate the sound as you want, and other sound banks can also be loaded. Maybe it's the DOS or the PC itself, which is very special and came to me with errors that I was able to sort out to some extent. I have aweutil in version 1.35, version 1.20 produced the same error. I got the drivers from Phils Computer Lab. Almost forgot, I will also clean the ISA contacts, but the card looked like new when it got here.

Hi!
Random Progress: My Dallas RTC is empty so the defaults have been loaded. But made no difference with aweutil. It was the defaults all along. OK, then I deactivated the L2 cache as a test, and yes, aweutil works as it should. So something defective in the L2 cache? Reactivated and still working? I don't know why or for how long, but I'll take it. No idea what version of Sam and Max Phil had, but this one can't work due to the memory manager. Then I accidentally came across another Vogons thread. Colonization is supposed to work with MIDI emulation under DOS, and it works and sounds great.
Not bad, right?