Step one: remove the metal items and the capacitors:

The silkscreen indicated polarity and gave each component a number, so I wrote down each corresponding rating for each capacitor. The bracket and game port shield came off easily and I submerged them in vinegar. The potentiometer was tricky because I don't have a soldering station with vacuum, only a solder sucker, so I had to spend time doing this bit by bit without scorching the PCB. This is how it looked once I removed it:

Step two: I used vinegar again (no isopropyl alcohol here) and some cotton buds (or q-tips, if you're not British) to swab the board, contacts, etc. I left some vinegar on the rusted pot contacts for a few minutes as well. I then rinsed the board and dried it. I used washing up liquid and a scouring pad to clean up the gold contacts and the rusty spots and this technique worked quite well:

The cleaned PCB:

Step three: I removed the metal items from the vinegar, rinsed and dried. Most of the actual rust had come off but I used the scouring pad additionally to get off as much of the actual corrosion as I could, as it had darkened the metal.

Step four: resoldered the pot, which was looking much better than before. Looked through my collection of components and, luckily, had replacements for all the caps. This isn't a high-load card or one that will get hot so I wasn't bothered about using solid caps, just reliable ones. Soldered them all back in, then replaced the shield and bracket:

And here's how the back of the card looks following the elbow grease:

And a final overview of the card. Looks awesome. I had a big grin on my face. And I did all this while cooking the kids' dinner!

Step five: testing!! Took this as an opportunity to test out the VIP board HighTreason sent me during the week. There are only 3 ISA slots on this board, one of them being occupied by a Cirrus Logic VLB card. I placed the Amstrad card in one of the slots adjacent to it and got no video at first. Changed the interrupt jumper to try some other settings - no change. Moved it to other other slot and it worked fine! No popping caps, no smoking, no unpleasant noises from the speakers. It did seem to be picking up quite a bit of noise from the hard drive I/O though (I have seen this mentioned on the web). Fired up Wolfenstein 3D and saw that magic indicator!

At first I had no audio coming out of the speakers whatsoever and I was a bit disappointed (but not surprised). However, I realised that audio had merely been disabled in the options. The reward for my hard work: an Adlib clone for £30, and pure, unadulterated OPL2 audio!!!

very nice!

Wow, that cleaned up really well!
I expected the ISA fingers to end up clean but chewed up on the edges after the rust removal process, but in the end you got amazing results!
How's the potentiometer, any scratchiness?

Congratulations on a job well done ! 😀

You did a fantastic job! Saw that auction but the condition put me off. Re isopropyl, Maplin sells it in an aerosol. But I reckon vinegar/acetic acid would have had more cleaning power in this case anyway.

bjt wrote:

You did a fantastic job! Saw that auction but the condition put me off. Re isopropyl, Maplin sells it in an aerosol. But I reckon vinegar/acetic acid would have had more cleaning power in this case anyway.

Cheers, man. To be fair I won it by accident. Had I seen the pictures properly I might not have bothered. It's also some kind of miracle that the guy bothered putting it online in the first place. I've learned something valuable from the experience no doubt.

I wanted to buy it but then saw the corrosion and rust... glad it went to caring hands and a good home 😀

Whoo! That's a very nice card you've got there... Try playing some tracker music on it and see how well it can rock 😎

keenmaster486 wrote:

Whoo! That's a very nice card you've got there... Try playing some tracker music on it and see how well it can rock 😎

I know nothing about FM tracking - did a lot of composition back in the day with my GUS but have only recently heard about the Adlib connection. Where can I find out more?

brassicGamer wrote:

I know nothing about FM tracking - did a lot of composition back in the day with my GUS but have only recently heard about the Adlib connection. Where can I find out more?

OPLx (vogon member) has listed many OPL2 trackers on his website http://oplx.com/opl2.htm.

If I had to name one song to play on OPL2, it would be The Alibi by Laxity of Vibrants. The song is in D00 format, playable with Vibrants music player.
Here's a youtube video playing it in DosBox https://www.youtube.com/watch?v=sXto5fBFC1E

Nice sound card by the way. Pure Adlib-compatible OPL2 with standard (non-MIDI) joystick port. Amstrad card also connects the OPL2 chip IRQ pin to ISA bus, while an unmodified Adlib drives no IRQ pins by default (there's empty place for jumper pin headers). As most of the passive components are surface mount and on the back side of the card, it's hard to do any comparison with a real Adlib card. But what I could see from the blurry pictures on the net, the Amstrad card uses more common LM324D op-amp and (unknown to me) TDA7233 speaker amp, while Adlib card uses archaic RC4136N op-amp and common LM386N-3 speaker amp.

I expect there will be not much difference in the tone, unless the Amstrad card has very different analog filter.

Thanks for the info - can't wait to try it out. Given the lack of info about this card maybe I will try to pull together some info about the chips. I'll do some recordings and upload them for comparison.

EDIT: forgot to mention I found a reference to this card in a thread 8 years ago by DonutKing.

Well, after realising I hadn't tested the functionality of the game port, I plugged the board in a couple of weeks later and...

nothing.

It's dead 🙁

With little to lose I tried a bake and that had no effect. So now I'm considering the following options. I work at a university so software, equipment and components are plentiful in supply:

- Harvest the components and make Sergey's adlib clone.
- Harvest the components and make a replica of the rev.B original Adlib.
- Reverse-engineer the board I have.

Although the latter is clearly the most time-consuming endeavour, there may be some benefits:

- It appears to be a single-layer, double sided board.
- The card has a built-in game port.
- There are no other projects (that I know of) like the above that allow one to make their own OPL2 card with game port built in.
- I want to learn more about electronics.

Any thoughts?

The bad side is that I will have to de-solder, and probably test, every component on the board.

I don't know if harvesting the YM3812 and it's amp is so much worth the time... both are plentyfull and cheap - unless you have access to a good desoldering tool and can remove them easily.
I can vouch for Sergey's adlib clone, it seems easier to build since you can get a pcb from him - but the other card is looking better 🤣

Okay, no harvesting. The card is worth more to the community than the components are, so I'm going to go all in. I don't know how long it will take me but hopefully I can find a colleague in the electronics department who is also enthusiastic about the project and can advise me.

My aim is to produce schematics and component lists to those similar to Sergey's (open-source, of course), so that anyone with these plans can make their own OPL2 / game card. I may even be in a position to produce additional cards if there is enough interest, similar to keropi's Music quest clone and shock___'s GUS remake.

I notice that my card also the option to change the interrupt but that it is currently hardwired. If I can replace this with a jumper block, this may a useful feature (although I can't see how - 388H is expected by everything for compatibility reasons AFAIK). Obviously the IRQ jumper is for the game port only.

Go for the reverse engineering. It's arduous but rewarding!

No the interrupt is not for gameport. Original Adlib has a jumper block for irq selection but it is not soldered on.

Most likely not a big issue as it looks like a standard gameport with ne558. Most likely it gets its trigger from one of the ls138 chips and data is buffered by nearby ls244.

The YM3812 has built-in timers and can generate interrupts with them, if the IRQ line is connected. Since the default was obviously 'not connected' it will be hard to find software that can take benefit.

Dumb suggestion, but do you have the means to check that the volume pot is working? Those things have always looked quite prone to damage.

As simple as the card is, I'd be inclined to think that it's a fairly simple fix.

Does it just not output sound or are there other indicators that it is dead?