I've one of those that I haven't used too much. It was initially jumpered for headphones (which made it noisy), but I changed the jumpers to disable the onboard amplifier. You've likely already done that, but I thought I'd mention it just in case.

This is a common issue with sound cards, especially older ISA sound cards. They pick up excess voltage that makes its way into the audio signal and then outputs as unwanted noise.

One possible solution is to try different slots to see if specific slots have reduced noise. It likely won't eliminate the issue entirely, but can potentially help mitigate it.

The permanent solution is to use a different card with less or ideally no noise. I tend to favor cards like the Adlib, Thunder Board (for Adlib only), GUS Extreme, AWE 64, and Roland cards (LAPC-I, SCC-1, MPU-401AT), as they tend to be noise free in my experience.

There are also modern ISA cards like the Orpheus, Blaster Board, etc., that are also designed with quality components and tend to have clean output as well.

Repo Man11 wrote on 2023-06-16, 14:53:

I've one of those that I haven't used too much. It was initially jumpered for headphones (which made it noisy), but I changed the jumpers to disable the onboard amplifier. You've likely already done that, but I thought I'd mention it just in case.

Thanks. I actually did not.

I just tried that, I am not even sure what setting is what. But when I changed it, it was first like a big storm, which then faded down. After that the noise was gone if nothing was played. But any Music sounded like garbage.

https://www.youtube.com/watch?v=eQ0vbcaxsMo
Excuse the pic quality. For 720x400 I didnt set up any scaling.

Shponglefan wrote on 2023-06-16, 15:37:

This is a common issue with sound cards, especially older ISA sound cards. They pick up excess voltage that makes its way into […]
Show full quote

This is a common issue with sound cards, especially older ISA sound cards. They pick up excess voltage that makes its way into the audio signal and then outputs as unwanted noise.

One possible solution is to try different slots to see if specific slots have reduced noise. It likely won't eliminate the issue entirely, but can potentially help mitigate it.

The permanent solution is to use a different card with less or ideally no noise. I tend to favor cards like the Adlib, Thunder Board (for Adlib only), GUS Extreme, AWE 64, and Roland cards (LAPC-I, SCC-1, MPU-401AT), as they tend to be noise free in my experience.

There are also modern ISA cards like the Orpheus, Blaster Board, etc., that are also designed with quality components and tend to have clean output as well.

I am actually looking for something...normal or barebones. I neither need something like a roland or added sounds and whatnot. I just want to get the sound as I had it back in the 90s with my "normal" soundblaster, and the ESS actually comes very close. Is there any you could point me to? Just "plain" SB without any bells and whistels (and therefore hopefully inexpensive).

That said, to me its kinda weird, that there is nobody attempting to "fix" the excess voltage part. Should be possible by just having a modified ISA Riser Card, right? I mean...if anyone bothered to create something like that.

Yes, I've found turning off the CD and PC speaker audio in the mixer settings helps tremendously.

Also jumpering it for line out rather than internal amp.

One big problem is that there is very little "power supply rejection ratio" on the parts of these old cards, any noise or other deviations in the voltage rails will end up in one way or other in the final output. Since the power supply itself cannot take reference at place where power is consumed, it cannot counter them in any real effect and there will always be modulation of the rails by instantaneous current needs of all the remaining components in the computer. Competent sound card has a high PSRR power regulator to create local rails out the dirty ones from ISA slot.

Another major problem is the ground currents of various other components polluting the local reference, this can be combatted by moving the sound card to the furthest away slot from power supply, this has the added benefit that card is next to bottom of the case and gets some electrostatic shielding from it which helps a little to reduce various problems. Sound card itself cannot do much about this problem, if it is in an unfortunate location in the system it will suffer.

Ground loops within the machine itself are one more problem, such as from CD-ROM to the sound card. Better sound cards use a differential input for the CD and this eliminates the problem but none of the low end and cheap things do that. PC speaker input is another source of discomfort but I have not seen any card out there trying to do anything with it. There is a thread here to do it well enough somewhere though.

Tiido wrote on 2023-06-16, 18:06:

Another major problem is the ground currents of various other components polluting the local reference, this can be combatted by moving the sound card to the furthest away slot from power supply, this has the added benefit that card is next to bottom of the case and gets some electrostatic shielding from it which helps a little to reduce various problems. Sound card itself cannot do much about this problem, if it is in an unfortunate location in the system it will suffer.

The biggest problem with sound cards is the very poor PCB routing.
Especially the old ones, which are still two-layered.
For example, the Diamond Monster MX300, based on the Aureal Vortex chipset, is a complete horror from a modern point of view. Trying to create gaps in an ground plane is just a tutorial on what not to do.
Alas, old sound cards are not about sound sensations, they are about nostalgia for the old days. 🙁

Another thing that helps quite a lot is using a modern power supply that has magnitudes better voltage regulation and outputs way cleaner power than the horrid things of yesteryear.

Kordanor wrote on 2023-06-16, 15:49:

I am actually looking for something...normal or barebones. I neither need something like a roland or added sounds and whatnot. I just want to get the sound as I had it back in the 90s with my "normal" soundblaster, and the ESS actually comes very close. Is there any you could point me to? Just "plain" SB without any bells and whistels (and therefore hopefully inexpensive).

Strictly speaking, if you're looking to recreate the sound you grew up with, the best option is usually the same sound card you had back in the day. But this also means accepting any quirks of those cards including noise.

If you're looking for clean audio output, I'd look to modern Sound Blaster compatible cards like the Orpheus, Blasterboard, etc.

That said, to me its kinda weird, that there is nobody attempting to "fix" the excess voltage part. Should be possible by just having a modified ISA Riser Card, right? I mean...if anyone bothered to create something like that.

In most cases the problem is going to be the design of the card itself. A lot of cards were designed to be cheap consumer devices, not produce super clean output. Especially since just having a sound card was a big novelty at the time.

This is an issue that even persists in hardware today. I have similar noise interference with modern motherboard built-in audio and with external sound interfaces on my studio PC. The latter of which required a somewhat expensive USB isolator to resolve.

If you dont hear the ISA bus and all other perepherials buzzing around in the background it isnt the real thing 😁

For my radio hobby, I often do use AF transformers. They provide galvanic insulation between my PC's soundcard (or TNC) and the shortwave radio / FM scanner.
Most amateurs these days would rather use opto-couplers, though.

Anyway, the problem of digital electronics is a very analogue one.
Like switching power supplies, digital electronics work by rapidly switching on-off.
This causes fluctuations, spikes in voltage.
What's even worse, these noise signals are square-wave (or sawtooth type, less bad), which cause harmonics.
At some point, they will cause malfunctions in nearby ICs. That's about when we talk about RFI, Radio Frequency Interference.

A counter measure would be to use separate, grounded chambers for each digital components (expansion cards).
This used to be common radio transceivers or in professional equipment like from R+S.

Next best thing would be to use blocking caps/low-pass filtering caps for the power source of each IC.

I was thinking out loud about this a while ago in this thread.
Some of the capacitor values are being discussed.
De-noising and capacitors

Doing so would prevent both from ripple, as well as compensate for voltage peaks.
The ICs then can switch on/off as much as they please without causing fluctuations on the power rail.

Um, but at some point it's perhaps better to build a metal enclosure for the soundcard.
A modern PC (past 486) really is a jammer.

If it sounds worse/noisier with the onboard amplifier disabled I have to wonder if there is something wrong with the card?

I did check 2 other things now:
1. I did connect a different power supply from an active, running PC to the CD Drive. And Voila...the BopBopBopBop on the left side was gone.
2. I also tried a different drive...problem gone as well.

The very silent white noise obviously is still there, but that was never the issue and is easily filtered out. I didnt test the CPU "howl" but this is likely not going to change.
Anyways...looks like I am going to hunt for yet another drive.

Kordanor wrote on 2023-06-17, 23:53:

1. I did connect a different power supply from an active, running PC to the CD Drive. And Voila...the BopBopBopBop on the left side was gone.

Wooow. Becareful with that. Mixing two power supplies isn't trivial.
There might be differences in ground etc, especially if the power plugs (and phases, thus) are reversed on each PSU/PC chassis.
Anyway, it gratefully was just a parallel connection and didn't cause harm. Never try to link PSUs in series.. 😵

Edit: If you had access to a scope, you could theoretically check the different power rails for noise.
Maybe it's merely one of the voltages that's very noisy. That would making de-noising a bit easier.

Jo22 wrote on 2023-06-18, 00:12:

Wooow. Becareful with that. Mixing two power supplies isn't trivial. There might be differences in ground etc, especially if the […]
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Kordanor wrote on 2023-06-17, 23:53:

1. I did connect a different power supply from an active, running PC to the CD Drive. And Voila...the BopBopBopBop on the left side was gone.

Wooow. Becareful with that. Mixing two power supplies isn't trivial.
There might be differences in ground etc, especially if the power plugs (and phases, thus) are reversed on each PSU/PC chassis.
Anyway, it gratefully was just a parallel connection and didn't cause harm. Never try to link PSUs in series.. 😵

Why would they be linked in series? You mean there is some voltage going over the IDE connection back and might not "mix well"? I only used 1 molex connection from that other power supply putting that directly into the CD drive. The idea being to "absorb" these irregularities in that other circuit.

Btw: One thing I didnt mention before: The CD audio plug had never been connected, not with the old drive, not with the new one. So that one had been irrelevant.

Kordanor wrote on 2023-06-18, 00:16:

Why would they be linked in series?

Just saying. Never mind. There are indeed some people out there who wire PSUs in series, as if they were batteries.
If they do need 18v, they'd use two 9v power bricks and wire them in series (minus, plus + minus, plus)..
That even works, but is very unsafe, as it will cause damage on the PSUs on the long run (if not instantly).

Sorry for the tediousness, but Bob Pease did not design sound cards.
Maybe this card is noisy for everyone?

Much of this has been mentioned before, but here are some general tips for cleaner output:

• Use a modern, high quality ATX PSU, if the motherboard supports it. If you need -5V, there are modern adapters for that
• Turn off the amplifier on the sound card if possible (usually there's a jumper setting for this)
• Mute any unused inputs in the sound card mixer, especially pc speaker, microphone and line in
• If there's a separate volume setting for the wavetable header in the mixer, mute that as well, unless you're using it
• Don't connect PC Speaker and CD-ROM audio cables to your sound card. Use the front 3.5 mm jack for CD audio instead, or a SPDIF cable if supported (e.g. on CMI8330 cards)
• Don't buy sound cards with FM radio or a modem on-board. Those tend to be noisier

That said, some sound cards are cheaply built, and no matter what you do, you won't be able to get a completely noise-free experience.

Perhaps a photo of the soundcard can be used to identify possible capacitors that can then be verified and if need be, replaced.

As I mentioned in my other post, I replaced my CPU, which was a AMD K6 II 500Mhz 2.2V with a AMD K6 II+570Mhz running on 600Mhz at 2.0V.
I already realized before that the CPU noise transmitted over the ISA Card significantly decreases if you downclock the K6 II to just 166Mhz.
Now after the exchange, I would say that the CPU based noise on the ISA card is still there, but substantially less, if you compare 600Mhz (new) to 500Mhz (old). So my guess is that the Voltage of the CPU also does make a difference.