no, for real. Get an outlet tester, and make sure the earth ground is in fact, actually an earth ground.

revolstar wrote on 2024-11-09, 10:16:

dionb wrote on 2024-11-09, 10:11:

Have you checked the earthing/grounding? If that's the cause, a different card won't make a difference. Would be a shame to throw money at the problem before being sure.

Aye, I've checked the grounding points on the card, they seem ok.

Not on the card, on the power outlet you hook your PC up to.

Chances of it being bad depends on where you live - the 'aye' suggests Scotland and UK may have many faults, but lack of robust (some would argue overengineered) electrical wiring including all sockets having had compulsory earth wire for ages and certification to be sure it's actually implemented is not one of them. Still, things can and do break and some electricians (or previous inhabitants of a house) will always be cowboys, so worth checking anyway.
Other extreme is here in NL where earthed outlets weren't even allowed in living spaces until 1999 and there's no obligation to have systems checked/certified by a qualified electrician except when a house is first built...

Shielded audio cables exist for a reason..

Whether or not the PCs sound card, motherboard or other device is creating too much noise, the path from sound card to amplifier is protected.

It cut 90% of noise for me..

dionb wrote on 2024-11-10, 10:14:

Not on the card, on the power outlet you hook your PC up to.

The electrical wiring in my apartment is pretty much ok, save for a few minor idiosyncrasies left behind by the previous owners. The grounding in the wall socket is ok as well.

As for the cable shielding as the others have suggested - both my retro PCs use the same 5.1 speaker setup and only the Win98 rig is affected by this. Do bear in mind that the buzz can be heard ONLY when I drag and drop stuff on the screen, NOT when I move the mouse cursor or when I click stuff. If this was a shielding or grounding issue I'd get more constant buzzing I suppose?

Haha, guess what?

I replaced my SB Live! with SB Audigy - the buzzing persisted. Then I noticed that dxdiag crashed every time it got to the DirectSound check. I reinstalled both the soundcard driver and DirectX - the buzzing persisted and DirectSound apps crashed. Then I reinstalled Windows 98 and this time round I chose the WDM driver for the SB instead of the VXD driver - the buzzing is gone 😁 Phew, what an ordeal this has been!

I do also "hear" the system(s)

Like if the storage (CF) and CPU (CX586) usage vary, the sound it produce also vary. When I load a dos game, the pitch go up and louder when it is loading...
Also moving a window in windows make a faint buzzing noise higher than the noise floor.. (Moving the mouse alone do it too)

Ground look fine too.

I did route my 486 audio output (Pro Audio Spectrum 16) thru the input of my main Ryzen PC (Sound Blastar RX 7.1) and normally I leave that to "mute" when not playing dos games else I always hear so various amount of light buzzing sound. Even when the 486 is off.

I assume that the 486 sound card just catch all the interference it can catch and that endup in the audio out. And I assume the cable between both sound card also act as an antenna. From the CPU, the BUS, the whatever electronic in the system, and also the ambient interference from other devices.

But what make the loudest noise on the 486 audio is when I move a window on the Ryzen (I note "window", moving the ryzen mouse alone does not produce extra buzzing sound and muting the 486 eliminate that noise).

486 sound card have a massive ground plate in it.

Maybe it's a ground loop? Everything is connected to the same outlet.
I will look for a shielded cable and see it that help.

revolstar wrote on 2024-11-13, 14:29:

Haha, guess what?

I replaced my SB Live! with SB Audigy - the buzzing persisted. Then I noticed that dxdiag crashed every time it got to the DirectSound check. I reinstalled both the soundcard driver and DirectX - the buzzing persisted and DirectSound apps crashed. Then I reinstalled Windows 98 and this time round I chose the WDM driver for the SB instead of the VXD driver - the buzzing is gone 😁 Phew, what an ordeal this has been!

I would not have guessed! Good for you!

revolstar wrote on 2024-11-13, 14:29:

Haha, guess what?

I replaced my SB Live! with SB Audigy - the buzzing persisted. Then I noticed that dxdiag crashed every time it got to the DirectSound check. I reinstalled both the soundcard driver and DirectX - the buzzing persisted and DirectSound apps crashed. Then I reinstalled Windows 98 and this time round I chose the WDM driver for the SB instead of the VXD driver - the buzzing is gone 😁 Phew, what an ordeal this has been!

This reminds me of an experience I had with an X-Fi Titanium, probably over a decade ago! I installed the card in a system running Windows 7, initially using the generic HDA driver built into Windows. I only wanted the X-Fi because the motherboard's built-in audio was extremely buzzy, so I figured that the HDA driver would suffice (and perhaps even be preferable to the bloated Creative software).

Much to my dismay, the X-Fi's analog output was nearly as noisy as the integrated! Fast forward a few days. I decided to download the Creative drivers so that I could use their equalizer. Lo and behold, all of that analog interference completely went away as soon as the driver installed.

I still don't know why or how that worked, but there it is. Apparently, drivers can somehow improve a sound card's analog signal path. 🤔

But wait guys, there's more! Out of (morbid?) curiosity I've tried the VXD drivers again - so far everything's ok, the buzzing's still gone. Go figure!