SoundBlaster Pro 2.0 recapping

[momaka]

Re: SoundBlaster Pro 2.0 recapping

Hi Dusko,

Glad you came back to report your work.

The Sound Blaster Pro was super noisy on 2 of the mobos while the other 2 were surprisingly clean, even at full volume (actually, no noise at all). I thought recapping it would get a cleaner sound from the other two mobos but didn't happen that way.

What kind of noise are we talking about here? Static? Hissing? "Digital" "CPU thinking" noises?

I know that on certain motherboards, it's a good idea to disable/mute certain inputs (like PC Speaker, CD Audio, and etc.) in the mixer, as some motherboards tends to cause more noise than others and get picked up by those inputs.

Grounding in the case can matter too. If the case has any plastic standoffs for the motherboard, replace them with brass (or any other metal) ones.

... the board looks great but I haven't noticed any major improvements in sound quality, maybe a little more bass but not so sure about that. I'm going to need to do some recordings with my other Sound Blaster Pro (which is unmodified) and compare it to this one.

Shouldn't really be a difference. The old caps would have to be very bad (especially on the headphone/line output) to make any difference in the sound quality. Also, I don't see many ceramic or film caps, so my guess would be that most of the electrolytic caps on that board filter digital IC power - i.e. where there really is no benefit from special audio caps. Probably even low ESR won't matter either.

Nevertheless, I would still say this was worthwhile doing, because now you won't have to worry about the electrolytic caps on that card for at least another 15 years.

I got a ESR meter and the old caps seem fine (@120Hz) but I'm not an expert in electronics and caps are tricky to test, I found a couple of ESR charts online with different values so I don't know

They are likely OK. Charts probably won't be that much use for these small caps. Reason I say that is because, depending on the cap brand and series, it is okay for some small caps to have quite "high" ESR (that is, relative to larger caps). Even up to 1-5 Ohms for a small 5 x 11 mm cap may still be considered "in spec"... or not (depends somewhat on the series). But for GP caps (i.e. not specifically low ESR), 1-5 Ohms is usually considered "OK".

I'm still happy about this project, it's something I wanted to do for a long time

Well, it's always nice to see old hardware getting restored, IMO.

[sam_sam_sam]

Re: SoundBlaster Pro 2.0 recapping

My Sound Blaster Pro recap project

Was recapping these sound cards worth the time and effort

The reason I am asking is a lot of the type mother board that you are referring to are obsolete what are using them for if you do not mind me asking

I have restored ( recapped power supply new hard drive new cmos battery ) a 8200 elite computer for a battery tester machine that I have that I did not need a up to date computer for it work correctly

I am about to restore another 8200 elite computer to basically run a 3 D printer that I would like to buy very soon

I also restoring ( recapped the power supply-[ possibilities recapping the mother board as well ] ) IBM 8183 WGX this computer is older than the other two computer that I was talking about earlier ( I had some real issues getting this computer to work correctly)

This computer I going to run a Radio Shack volt meter data logging feature that this meter has
Also use this type of computer to run a Basic Stamp 2 from Parallax

I use to do Basic Stamp programming probably about 10 years ago I wanting to get back in doing this
I use to use a Windows 98 computer for this now I going to jump to Windows XP

I do not think that I could bring back that Window 98 computer back to life ****** maybe

[Dusko75]

Re: SoundBlaster Pro 2.0 recapping

Hi momaka,

Once again, I didn't know you guys replied, weird, I'm supposed to get notifications in my email.

What kind of noise are we talking about here? Static? Hissing? "Digital" "CPU thinking" noises?

It's not hissing or static, it looks more like CPU thinking, moving the mouse, apps loading, etc. Imagine if you can "hear the data flowing", that's what it sounds like.

I know that on certain motherboards, it's a good idea to disable/mute certain inputs (like PC Speaker, CD Audio, and etc.) in the mixer, as some motherboards tends to cause more noise than others and get picked up by those inputs.

Yes, only muting the FM (Synthesized music) greatly reduces the noise, no idea how to filter that.

Grounding in the case can matter too. If the case has any plastic standoffs for the motherboard, replace them with brass (or any other metal) ones.

Yes, there's a couple of brass standoffs so ground is not the issue.

Well, it's always nice to see old hardware getting restored, IMO.

Yes, that was still a nice experience, I never recapped a board before and I wanted to do that so the SB Pro was a good excuse.
Thanks for your comments!

[Dusko75]

Re: SoundBlaster Pro 2.0 recapping

Was recapping these sound cards worth the time and effort

Absolutely! I never recapped a board before so the Sound Blaster Pro was a great excuse. Also, learned a few tricks desoldering the old caps so whatever the next project is will be faster and easier to do. Anyway, those caps were 25 years old! They may still work but why not refreshing the caps on an old piece of technology that you love and will use!! And.. it looks so beautiful now!

The reason I am asking is a lot of the type mother board that you are referring to are obsolete what are using them for if you do not mind me asking

Yes, they are very obsolete indeed!, I'm using them for nostalgic reasons basically, and being able to play old computer games in the real hardware they were designed for. I collect old computer games so obviously you want to have the hardware too, it's a pain in the a#%! sometimes, this stuff is old and tends to fail. You just have to love it!
You can emulate all this in a modern computer, I do that too but nothing like the real stuff!

[momaka]

Re: SoundBlaster Pro 2.0 recapping

It's not hissing or static, it looks more like CPU thinking, moving the mouse, apps loading, etc. Imagine if you can "hear the data flowing", that's what it sounds like.

Yup, that sounds like an analog input picking up noise and mixing it with the stereo out. If using Windows XP and 2000 (and I think earlier versions of Windows have it too), make sure to check all of the volume controls in the control mixer to show up. That way, you'll be able to mute any that you don't need. If that doesn't get rid of the noise, I'm not sure what else is there to try. But that noise is not a sound card fault. It's just either poor PCB design/layout or an input not being muted and picking up noise, as I noted.

You can emulate all this in a modern computer, I do that too but nothing like the real stuff!

+1

For me at least, getting the old hardware to work as intended is as much part of the game as is playing the old games afterwards.

Like you said, this stuff is old and doesn't always work right. Add to that the difficulty in finding the correct drivers and hardware info, along with any possible known bugs... and things can be quite challenging to make these old PCs work right. But I find that usually once everything is set, those old PCs also tend to stay working and be quite reliable too. So they are definitely a labor of love.

[Logistics]

Re: SoundBlaster Pro 2.0 recapping

That's an interesting experience, and I'm going to have to suggest recapping all hardware involved (motherboard and absolutely, the PSU) to be sure. When I recapped the portions of my SB16 that mattered (power traces and audio output) I probably, did wrong by using low esr caps in the audio stage as the volume could barely be raised in Windows before it was super loud. But it wasn't noisy. However, I was running on a PIII so design differences are present. I should just send that card to someone on here to play with because I'm not likely to ever use it again.