For Build/Pmode games you'll be using SB anyway. I imagine the games only supporting DSS and not also SB aren't many, and especially not pmode stuff.

Another question: any chance for the line-out stereo jack to be replaced with 2 RCAs (like on the AWE64 Gold, and better make it 100% compatible with the bracket from the Gold)? Of course, not everyone has a Gold to harvest a bracket from, but at least it would contribute to the final sound quality and make an explicit convention on the bracket type.

If there was a cheap and plentiful source of sound cards with RCAs to cannibalize things from I would have gone with that *dislikes TRS a whole lot* but as is, the most common bracket type will fit the card and that's really the only reason things are as they are.
If a custom bracket can be made with cost of no more than 2€ per bracket I'm all up for anything.
The option of having a PCB based bracket is actually attractive outside relative fragileness (it is not hard to snap or deform 1mm thick PCB), it has very low cost (waaaaay below 1€), can have any sort of orientations for holes and whatnot and I can have any sort of writing/symbols on them aswell.

Ok, 2 euros seem feasible on the first glance. I'll PM you later on this, just don't discard this option yet.

Ok, I await for response ~
It actually is beneficial right now to have excess realestate on the card in that area, I can move the connectors around or even change them without disturbing anything that requires much care to redo haha.

I never thought to ask before: is this a two- or four-layer design?

It is 2 layers, 4 would have made my life much easier though, lot less attention has to be put into routing power and signals without compromising either.

I definitely want one (or possibly 2) of these! Always thought that the OPL3-SA chipset deserved a really good design to be put on and i thank you sir for the effort! The software seems to be great too.

That is what I was thinking myself, almost all the implementiations are subpar and eventually I had enough and made my own.
The software can be used with other YMF71x based cards too, all the features specific to my card get hidden away now.

If you need metal brackets fabbed up, one of my clients is a stamping company and they have a large prototype shop that can do small batches quickly and cheaply. All they need is a sample part. I'm certain cost would be reasonable. I've talked to them about making ATX I/O shields for AT motherboards.

The question is how cheaply. I wouldn't be able to create a sample but I do have a drawing made with all the measurements :

(Those measuremests are takes from some random bracket, it would be nice to know what they actually are supposed to be and then add the custom bits on top of that).
There could be changes (such as going for RCAs instead), in the end it all comes down to cost and I'd like it to stay under 2€ range per bracket (shipping etc. included). Quantity would be 100 for starters.

That's still missing the PCB screw mounting part, or will it hang off the MIDI port screws like keropi's MPU cards?

Yeah, I see that's just the way of existing Yamaha based designs...

For audio jacks, the more common separation seems to be 0.5" (12.7mm) from jack to jack, and a common/safe hole size is 0.28" (7.11mm).

Also, depending on where the brackets will actually be manufactured, be aware that slight rounding errors are possible. The drawings I submitted had both metric and inch measurements, and they worked from the inch measurements, introducing a little rounding error, though it was usually only one or two hundredths of a millimetre (or less).

Also, pay attention to whether the jacks you intend to use are raised, such that they end up needing a hole centred within the bracket, or are slightly lower (toward the PCB surface).

I had chosen wider connector separation so that input connectors would be slightly further away from output ones. I also made the holes oversized a bit allow for some slack (and to accomodate both raised and lower TRS connectors, though not completely sure it works for the lowered ones very well).

I'll work on a revision of the bracket shortly, 640K!enough sent me a few files that show the supposed dimensions ~

firage wrote:

That's still missing the PCB screw mounting part, or will it hang off the MIDI port screws like keropi's MPU cards?

Yeah, I see that's just the way of existing Yamaha based designs...

I don't see any point in having the screw on top, more often than not I have to remove it to make the card fit properly in most chassis' I have. So yes, GamePort will hold the bracket in place.

In other news, I fixed two DB60XG modules I have that both went silent at some point. The DAC+ADC chip had given up on both. I could see lot of activity on I2S lines in relation to what music was doing but no sound came out. End result was using the same DAC as I do on my card for YMF721, and result is very nice without any hiss to complain about 😁


I'll provide a few recording utilizing the WB header soon too, and possibly a video.
EDIT : Recording has been made and added to the playlist : https://soundcloud.com/tiido/sets/recordings-from-t-04ybsc

EDIT2: Small error in SETYMF got fixed, I wasn't properly reconfiguring YMFDEC when changing YMF721 settings.

Tiido wrote:

I don't see any point in having the screw on top, more often than not I have to remove it to make the card fit properly in most chassis' I have. So yes, GamePort will hold the bracket in place.

Oh, you and your cases are the reason they've gone missing on my stuff! 🤣

Nice one with the DB60XG's. Those things are worth fixing for sure.

All WB modules are worth fixing, those things are getting more and more expensive and give so much soundwise, compared to FM anyway haha.

Here's some progress on the revision of the card :

* I have compacted the analog section far bit thanks to reducing footprints on the opamps. There's still some tidying up to do though.
* CD-Audio header no longer gets in the way of WB connector.
* I have added a 4 pin header for Line Out, it seems I don't really have space for a Line-In one.
* I added WB channel reversing jumpers (FLIP on top), I'm not sure if they will not get in the way of anything or not, DB60XG that I have got components on top rather than bottom toward the sound card.
* I also verified that I can use EPM70xxS rather than non S version, that opens up bunch more parts I can use for the CPLD. Also QFP part footprint should fit into the footprint of the PLCC so I can have more variety without a new board design. I'll update things with that soon.

TODO list for the revision :
*Add support for both active high and active low reset for YMF704/721. Need to snake around a new trace in already crowded area.
*Add 4 pin header for line-in (might not really be possible)
*Use smaller bus transceiver and FF
*Add provisions to allow DIY effect routing via WB connector like the MediaTrix card.
*Change WB GAIN from -6db to -12db. Unmodified DB60XG have insanely loud output which clips most sound cards' inputs.

End result was using the same DAC as I do on my card for YMF721, and result is very nice without any hiss to complain about

Man, it’s awful, what a mess. Don’t do it such way. As I remember, there ak4510 should reside, and this chip easily obtainable

AK4510 is a terrible chip compared to the replacement I used, linearity isn't super good and it is extremely noisy (increases card noise floor by over 9db !). I would have used some more modern DAC but the ones I got in my stash are 3.3V based. I absolutely don't care about the ADC feature and I even disabled it (wired the digital input of processing signal permanently to GND) to get less noise out the thing. Original state doesn't matter a single bit to me, if I can add improvements I will.

More progress on the revision :

*I managed to add 4pin header for Line-In
*Provisions for DIY effect routing via WB connector are added. 4 parts need to be removed and 4 wires need to be soldered to get that functionality.
*Smaller bus transceiver and FF are added in, lot of tidying up left to do though.

TODO:
*Active high reset support for YMF721/704, will be lot less headache due to extra space from switching out the transceiver chip.
*Add QFP CPLD footprint in the middle of PLCC pads.

Regarding the DIY option: any possibility to do that via SMD 0 Ohm resistors (with the corresponding traces on board) instead of wires? Just hate wires and patches 😀

It's going to be a blast to figure out a cool 98SE/DOS build with this plus DB50XG and an AWE64G, with an Audigy for mixing. All the resource allocations, mmm...