Is it always the same games that have noise or does it come and go?

Sounds to me like the card either needs to have new capacitors installed and/or you are getting a lot of ISA bus noise.

Either can be easily fixed.

Pics of your motherboard?

The CT1600 is pretty sensitive to bus & environment noise, so upgrading to the far less sensitive CT4500 would reduce noise. To stay 1993 period-correct you could look for less noisy cards. GUS and PAS16 immediately come to mind. GUS is prohibitively expensive, PAS16 far less so.

It’s NOT the CT1600 that are bad. I think it is a driver issue or just game compatibility.
The CT1600 sounds good with the DOS players provided with Creative install package.
.Wav and MIDI files play crisp and clear.
It’s just some games that Static is heard.

But the CT4500 seems to have better game compatibility and I don’t hear any static ever.

Most DOS games used 8-bit audio, they always sound a bit "fuzzy".

The CT1600 uses no drivers in DOS.

CT4500 having better game compatibility? Huh? What are you smoking?
It is a Sound Blaster Pro 2.0. It should work with every game out there that supports a Sound Blaster card in DOS.

And the CT4500 doesn't have real OPL3.

My pretty well educated guess is that the CT4500 has better ISA bus noise filtering as well as cleaner output overall.

If your motherboard doesn't have electrolytic capacitors on it, then it will be a very noisy board regarding the ISA bus. This leads to noisy sound cards that don't have good bus filtering built in.

Could also be a sucky power supply giving dirty power which the CT4500 is probably better about as well.

Another thing it could be is that the volume POT is dirty or the output plug has a poor connection. Yes, it could be the same on both cards. Just because you swapped out a card doesn't mean that they both don;t have the same problem.

Have you tried then in another system that the CT4500 works well in?

What speakers are you using with the SB Pro 2.0? Have you tested those speakers with the CT4500?

Still no pics of your motherboard (NOT STOCK PHOTOS).

You probably have a lot of noise on the ISA bus, your motherboard may have poor filtering in the first place or aging capacitors. Regardless, unless you recap it completely to check, or buy a server grade quality 486 board, you are served best by installing a card less susceptible to noise on the ISA bus. That often means installing non-period correct hardware from a few years down the line as there were no SB Pro compatible quality alternatives at the time. The GUS and PAS suck ass for games, despite being good cards overall. Either use the AWE64 and use its SB16 compatibility and wavetable synthesis, or buy a high quality SB Pro soundcard without wavetable (as these are often not in high demand) such as the Terratec Gold, Turtle Beach MonteCarlo, Aztech Pro16, AOpen S23, etc.

Intel486dx33 wrote on 2020-02-24, 18:20:

My 486dx4-100 computer build is suffering from audio Static
I have a Sound Blaster Pro 2.0 installed right now.

Hi! The SB Pros, being 8-Bit soundcards, were really dated when 486dx4-100 came out. "Cheap" 16-Bit no-name soundcards were considered current at the time.
Anyway, the OPL3 on the SB Pro 2.0 should handle fast CPUs just fine. If you like retro noise, or stuff from the demoscene, then the card is the right choice, II guess.

However: Did period-correctness -as we mean it- truely exist, even ? From what I remember, in practice, the 90s were an extreme mixture of old an new. 😀
Expecially, since because of the upgrade graze. Technology was evolving so fast, that people used ancient stuff with the newest motherboards (and vice versa).
Just think of these "overdrive" sockets for CPUs. Clint of LGR mentions them at https://youtu.be/Qt-0lqkJUKE?t=169

So strictly speaking, any configuration was period-correct, wasn't it ? Solely, because the fact it existed back then.
Except if we consider pre-built systems mentioned in 90s catalogues as the norm, of course.
But they're not exactly that what we had at home, right ?
How many systems were not modified/upgraded/downgraded soon after purchase ? 😉

If we look at it that way, then things look like this:
An MFM drive in a 486 PC: period-correct.
A 286 with CD-ROM kit: period-correct.
A 386 with HGC card: period-correct.
A lame duck (8088) with VGA: period-correct.
Win95 on a 386: period-correct.

Yes, I see that YouTube’s like “LGR” and “Philscomputerlab” actually don’t go for period correct but instead choose components that work best
That provide the video and sound the makers of the games intended the players to hear.
And I think that is important.