cde- wrote:

I'm wondering if someone has had a similar problem before, and if so does a solution exist (such as a hardware modification: adding caps, etc.)?.

Hi, Iremember I once started a thread about the ALS100+..
ALS120, ALS100 Plus audio fix ?

That being said, there are a few other interesting ALS100(+)/ALS120 threads at Vogons.
Unfortunately, I haven't the bookmarks at hand right now 🙁

Jo22 wrote:

Hi, Iremember I once started a thread about the ALS100+.. ALS120, ALS100 Plus audio fix ? […]
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cde- wrote:

I'm wondering if someone has had a similar problem before, and if so does a solution exist (such as a hardware modification: adding caps, etc.)?.

Hi, Iremember I once started a thread about the ALS100+..
ALS120, ALS100 Plus audio fix ?

That being said, there are a few other interesting ALS100(+)/ALS120 threads at Vogons.
Unfortunately, I haven't the bookmarks at hand right now 🙁

Thanks a lot. I do indeed also have an ALS100+ that is identical to the one in the thread you mention.

It does not suffer from this CPU-activity noise. Unfortunately it has an extremely high noise floor, which is very problematic. Also it does not support high DMA which is why I looked into the ALS100 instead.

cde- wrote:

Hello, […]
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Hello,

I got several ISA/PCI sound cards to test under DOS, and so far my favourite is the ALS100 (not plus). It is really easy to configure and has a very low noise floor.

Unfortunately as soon as the CPU starts being used in games such as DOOM, a very noticeable, low droning sound appears. Presumably this is caused by interference picked on the PCB by one of the components or PCB traces.

I'm wondering if someone has had a similar problem before, and if so does a solution exist (such as a hardware modification: adding caps, etc.)?

Thanks very much in advance.

Sounds like poor voltage regulation on the ISA bus, probablye due to bad filtering caps on the motherboard? Try it on another motherboard and see if you can reproduce the problem. If you can't, then recap the motherboard.

appiah4 wrote:

Sounds like poor voltage regulation on the ISA bus, probablye due to bad filtering caps on the motherboard? Try it on another motherboard and see if you can reproduce the problem. If you can't, then recap the motherboard.

That makes a lot of sense and I'm considering testing with another KT7A motherboard that I have.

Since then I have received my ES1868F card which is nice - I probably should have bought it first before ALS100(+)/YMF ISA/PCI cards. If anyone is looking for a cheap but decent ISA card I'd recommend it. I just had one bug where SFX would become mangled and turns into pops. I disabled the parallel port which fixed it.