You could locate the MIDI TX line, sever it and input whatever else from another card in there. Sound output is gonna be harder with some cards as the digital data often goes not into a dedicated DAC but into the main sound chip where the DAC will reside, requiring the host card to be initialized for sound to be usable.

Making actual WB modules is certainly an option too, but is a bit more involved due to some level of reverse engineering and PCB design involved. Some of those chips are not very well documented at all, other problem is that you cannot actually buy these chips either in case you want to make more so only donor hardware can provide them and sometimes that hardware is expensive enough already...

I see several ways here:
1) Just install one of these cards alongside with your main one, disable as much features as possible, leaving only MPU401. On some cards I think it is possible to disable it as well, feeding MIDI to gameport or wavetable.
2) Some cards may work without ISA slot, with some wires attached to midi input, sound out and power lines.
3) Just buy some NOS chips - some of them are still there.
4) Use one of these cards as donor. Careful desoldering may be not that easy, rendering the whole idea inefficient.
Lets start with ESS one. I've got the same board, but MIDI is missing. Supposedly It'll take either ES689 (not available on utsource) + ES981 (2$), like yours, or ES690 (2.5$) + ES981 (2$) (the empty footprint up top is for ES690). Both chips needs a DAC and an op-amp to work without ES186x. Another option is to use es692 (5$, should sound the same), but it needs a level shifter as well, since it's a 3.3V IC. Total price may be as low as 15-20$

Most of those cards have excellent codec and fm chips...I would just use them as intended.

Those are all good cards. It would be wasteful to rip out the chips.

If you can buy the standalone chips from somewhere that's a different matter.

There is probably a good chance to outsource some ESS chips (as Jager noted) and maybeee Crystal ones, true. I had this idea because it wouldn't render the card useless and you would be able to attach the daughterboard to it or to another card afterwards. To me having wavetable integrated into a sound card is limiting and more often than not I won't just use it because it's noisy or has bad FM synth etc. And with that I won't use it's MIDI capabilities. For example the AW32Pro (bottom left) is so noisy I cannot bear it even though the wavetable sounds pretty good. To me it's a waste.

However with some chips being able to be outsourced it's probably better idea to build an open source board with NOS components.

In some cases it's possible to eliminate noise by replacing the capacitors on the card. It's also not uncommon for cards to have capacitors that are below spec (in comparison to the datasheet) as some manufacturers wanted to save a few cents. This can also result in noise.

Might be worthwhile to try recapping the cards before taking out the chips.

Well, in the case of the mentioned card (AW32Pro), I did complete recap with mostly Panasonic capacitors (FC series) and if anything, the sound is somewhat clearer. Unfortunately the noise is more prominent. But thanks for your input, you made me think about outsourcing the chips and making brand new boards. It may be nice exercise. I'll probably start with the ESS chips which are more common than others. Preferably something using ES690F or ES692S (ES689F does not support reverb/chorus). I have yet to find a mention about MIDI daughterboard using these chips.

Are any of the proposed wavetables of a quality or character special enough to warrant a large project ? To me they seem like something one would test out for fun, to see what they are like, but then for the real gaming normally go back to the sound canvas or dream blaster or whatever, products in a superior quality class than the old cut-price turn-of-the-century soundcard wavetables.

So, the target market is a serious consideration. Or to look at it another way - how much would Average Vogons Member pay, for a daughterboard with ESS (or similar) MIDI on it. For me, it's zero, because I already have ESS sound cards and can use them if I want to, or could get one for ~$10-20 if I didn't have one. Dunno, just my opinion.

Guess what I'm saying is, you shouldn't approach this project for any commercial reasons, else you may well be disappointed and frustrated, but if you just do it as a project purely for fun and your own satisfaction (and whatever else happens is just a bonus), then go for it, and have fun! 😀

Those are all great soundcards! Sell them and buy a Serdaco - I'm betting you could get a decent amount for them if you list them right.

@Shreddoc: Yeah, you're right that it wouldn't be commercially plausible but that wasn't my intention at all. What I would like to see is a nice open source wavetable duaghterboard for anyone who has the skill necessary to build it. Right now there are not many options- either you'll buy an expensive second hand board or less expensive (but still pretty costly) one from Serdaco. I happen to own Dreamblaster X1 and it sounds fantastic but I was able to buy it used for cheap. I'm sure many people would love to add MIDI capabilities to theirs sound cards. Of course there is Dreamblaster S2... Well, I don't like it much. Most of the sounds are synthetized which I am not a fan off. In comparison, open source ESS daughterboard would sound nicer (my opinion) and would cost the same, maybe less. I have checked and ESS have schematics for MIDI daughterboards in their ES690F datasheet. This should be a breeze. If not for me than for someone else.

@badmojo: Maybe I will. Even tough I like to compare my favourite soundtracks on different wavetables, the truth is most of the time those sound cards are shelved in the dark in a box. The best thing for me would be to have three very nice sound cards with OPL3, ESFM and CrystalFM chips and some MIDI boards. If nothing else, this would greatly save me some space at home 😁.

Jager wrote on 2020-09-26, 10:28:

I see several ways here: 1) Just install one of these cards alongside with your main one, disable as much features as possible, […]
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I see several ways here:
1) Just install one of these cards alongside with your main one, disable as much features as possible, leaving only MPU401. On some cards I think it is possible to disable it as well, feeding MIDI to gameport or wavetable.
2) Some cards may work without ISA slot, with some wires attached to midi input, sound out and power lines.
3) Just buy some NOS chips - some of them are still there.
4) Use one of these cards as donor. Careful desoldering may be not that easy, rendering the whole idea inefficient.
Lets start with ESS one. I've got the same board, but MIDI is missing. Supposedly It'll take either ES689 (not available on utsource) + ES981 (2$), like yours, or ES690 (2.5$) + ES981 (2$) (the empty footprint up top is for ES690). Both chips needs a DAC and an op-amp to work without ES186x. Another option is to use es692 (5$, should sound the same), but it needs a level shifter as well, since it's a 3.3V IC. Total price may be as low as 15-20$

Hi,

ESS Wavetable is already in the pipeline,
i guess we will see soon a Dreamblaster ESS or something.

Well, good to know. You're working on it or someone else? Either way, shouldn't it be called ESSBlaster or AudioDriveBlaster since it won't probably use Dream chip? 😁

Some thoughts after datasheet digging - ES690 won't work without ES1xxx, ES692 datasheet even has daughterboard schematics, but I can't find replacement for TDA1311 - its a pretty crappy DAC.

You can divide down master clock of the chip to be the system clock for any modern DAC supporting the 16bit right justified format (most do). Some DACs can work with 33MHz rather than 16MHz (or lower) clock, such as PCM1781.

Jager wrote on 2020-09-27, 20:22:

Some thoughts after datasheet digging - ES690 won't work without ES1xxx, ES692 datasheet even has daughterboard schematics, but I can't find replacement for TDA1311 - its a pretty crappy DAC.

In the ES690 datasheet there is schematics for a daughterboard described as "daughterboard for any sound card". It seemed weird to me as there is no DAC in it.