Great work as always guys! 😀 A few questions:

1) Is the SBPro low-pass filter present, as with stock ESS 1868/9 cards? In my view, ESS cards have the best low-pass filter of all the SBPro clones, which makes them sound great in old "talkie" adventures and other games from the early 90s which used lower sample rates.

2) Is the stereo issue on the wavetable header fixed? Most stock ESS cards had the left and right channels reversed when using a wavetable daughterboard.

3) Any chance for SPDIF IN/OUT? For example, SPDIF_IN for connecting a digital CD-ROM audio cable and SPDIF_OUT for outputting noise-free audio for recording purposes.

Very nice! I keep going back to my ES1869 cards because I like them the best.

In theory, is it possible to add WSS with an AD or Crystal IC? That would truly make the design unique.

1) Same filter as stock ESS cards.
2)This is solved here
3) No SPDIF I/O unfortunately. We decided to keep this out due to cost. But there will be an I2S interface on expansion 😀

Exciting stuff once again! 😄 I really like the idea of the expansion header, this will open up a lot of possibilities for sure.

I have a few questions:

1) Any reason you added unpopulated space for the ES692? Isn't the ES690 the same chip but without the built-in sample ROM?

2) Is it possible to use the ES690 in conjunction with a wavetable daughterboard or do they share the same MIDI input and audio output channel?

3) You mentioned that the I/O header also includes audio now. How is this combined with the on-board ES1869? As in, does it only route the final mixed output of the ES1869 to the I/O header or does it for example also route the Line In separately to the I/O header? What about the other way around, would output from an expansion card be fed into the mixer of the ES1869 or can it directly output to the Line Out? Just wondering how flexible the audio path is 🙂

@Lennart

1. it's a proto - it can use either ES690 or ES692 , it is not sure if we keep U5 or not for the final version. Both sound similar but I cannot say 100% they are the exact same.
2. currently ES690 + ES1869 are "combined" as per ESS schematics, so the mpu for ES690 is always the ESS chip
wt audio is going to AuxB input of ES1869 so it is possible via muting either AuxB or MIDI to get audio only from one midi synth
3. expansion audio also goes to AuxB input of ES1869 so in the end everything passes from ES1869 chip

Thanks for the clarification!

(watching this space because one can never have too many retro sound cards)

It's beautiful 😃. Nice job 👍🏻

Nice work! Finally ESS gets the remake it deserves. It was always a shame that so little of the cards with their chips came with one of their IMHO fantastic wavetables, perhaps they were too late to the table by the time they came out.

Is anything implemented any differently then ESs would have it on the SB / mixer side of things? I could never get sfx from Transport Tycoon Deluxe (dos version) on any ESS cards set to SBpro for whatever reason, makes me wonder if it would work on this card or if it is some sort of bug with how ESS chips handle something (literally only game I've ever had an unsolvable problem with on an ESs)

Nice work so far, I'm liking what I'm seeing.

Some suggestions:
- Maybe move those smd electrolytic caps about 1cm away from the 78M05? I'd like to keep hot stuff away from passives whenever possible, to prevent the operational characteristics from changing too much when the board heats up.
- If the expected load on the regulator is below 200mA total, consider replacing the regulator with an LDK320AU50(R).
Digikey: https://www.digikey.com/en/products/detail/st … 20AU50R/9687063
Datasheet: https://www.st.com/resource/en/datasheet/ldk320.pdf
This regulator has a tiny SOT89-5 package, *much* lower quiescent current (100uA worst case) and is stabilized with an X5R/X7R ceramic capacitor of at least 1uF; you'll have to consult the stability plot in the datasheet to choose an appropriate value. This may potentially translate into a reduction in parts count, and cheaper parts in the BoM replacing big chunky electrolytic capacitors?
- Some alternative op-amps to the RC4580 in line-out mode: NE5532 (my favorite, a bit hungry for current but also has good all-around performance and is still pretty cheap), TL972 (cheap-ish, super-low quiescent current, rail-to-rail, commonly used on Mega Amps and Triple Bypass audio mods for Sega Genesis/Mega Drive), LM4562 (more expensive, but it's hard to beat its performance even with $50/pop audiophool parts, somewhat better balanced quiescent current vs. the NE5532).

Looks like I have another new retro card to get from you guys!

Wohoooo looks great!

I've wanted to see someone do this. I thought these chips were let down by cheap PCB designs for a long time.

Eep386 wrote on 2024-09-02, 19:56:

Some suggestions: - Maybe move those smd electrolytic caps about 1cm away from the 78M05? I'd like to keep hot stuff away from p […]
Show full quote

Some suggestions:
- Maybe move those smd electrolytic caps about 1cm away from the 78M05? I'd like to keep hot stuff away from passives whenever possible, to prevent the operational characteristics from changing too much when the board heats up.
- If the expected load on the regulator is below 200mA total, consider replacing the regulator with an LDK320AU50(R).
Digikey: https://www.digikey.com/en/products/detail/st … 20AU50R/9687063
Datasheet: https://www.st.com/resource/en/datasheet/ldk320.pdf
This regulator has a tiny SOT89-5 package, *much* lower quiescent current (100uA worst case) and is stabilized with an X5R/X7R ceramic capacitor of at least 1uF; you'll have to consult the stability plot in the datasheet to choose an appropriate value. This may potentially translate into a reduction in parts count, and cheaper parts in the BoM replacing big chunky electrolytic capacitors?
- Some alternative op-amps to the RC4580 in line-out mode: NE5532 (my favorite, a bit hungry for current but also has good all-around performance and is still pretty cheap), TL972 (cheap-ish, super-low quiescent current, rail-to-rail, commonly used on Mega Amps and Triple Bypass audio mods for Sega Genesis/Mega Drive), LM4562 (more expensive, but it's hard to beat its performance even with $50/pop audiophool parts, somewhat better balanced quiescent current vs. the NE5532).

I think the design is fine the way it is, but if we're suggesting changes, I like using the NJM4556 for the line-out buffer/amp. It has enough output current to directly drive headphones (I see the AC'97 header, so something headphone-capable would make sense) and has a wide supply voltage range (just in case it's running on 5V - the NE5532 is only rated down to 10V or +/-5V). The downside is that it's in a nonstandard package that's wider than a standard SOIC.

Congratulations guys, great project..as always! 👍

I was hoping that sooner or later, from your magic hat, an ESS-based sound card would come out 😄

I only have one question: why insert a USB connector that can only supply power? I mean, seen from this perspective, I would say it is only used to charge the phone..but obviously I don't think it is designed for this..so for what? 😉

He said the USB connector would be used by addon cards plugged alongside this one in the connectors above the ISA fingers. Or possibly in the smaller connector located behind the USB port. Or both. 😀

Amazing work guys, you keep bringing these goodies!!

lti wrote on 2024-09-02, 20:56:

I've wanted to see someone do this. I thought these chips were let down by cheap PCB designs for a long time.

Eep386 wrote on 2024-09-02, 19:56:

Some suggestions: - Maybe move those smd electrolytic caps about 1cm away from the 78M05? I'd like to keep hot stuff away from p […]
Show full quote

Some suggestions:
- Maybe move those smd electrolytic caps about 1cm away from the 78M05? I'd like to keep hot stuff away from passives whenever possible, to prevent the operational characteristics from changing too much when the board heats up.
- If the expected load on the regulator is below 200mA total, consider replacing the regulator with an LDK320AU50(R).
Digikey: https://www.digikey.com/en/products/detail/st … 20AU50R/9687063
Datasheet: https://www.st.com/resource/en/datasheet/ldk320.pdf
This regulator has a tiny SOT89-5 package, *much* lower quiescent current (100uA worst case) and is stabilized with an X5R/X7R ceramic capacitor of at least 1uF; you'll have to consult the stability plot in the datasheet to choose an appropriate value. This may potentially translate into a reduction in parts count, and cheaper parts in the BoM replacing big chunky electrolytic capacitors?
- Some alternative op-amps to the RC4580 in line-out mode: NE5532 (my favorite, a bit hungry for current but also has good all-around performance and is still pretty cheap), TL972 (cheap-ish, super-low quiescent current, rail-to-rail, commonly used on Mega Amps and Triple Bypass audio mods for Sega Genesis/Mega Drive), LM4562 (more expensive, but it's hard to beat its performance even with $50/pop audiophool parts, somewhat better balanced quiescent current vs. the NE5532).

I think the design is fine the way it is, but if we're suggesting changes, I like using the NJM4556 for the line-out buffer/amp. It has enough output current to directly drive headphones (I see the AC'97 header, so something headphone-capable would make sense) and has a wide supply voltage range (just in case it's running on 5V - the NE5532 is only rated down to 10V or +/-5V). The downside is that it's in a nonstandard package that's wider than a standard SOIC.

The TI NE5532 is rated to +/- 22V. Despite the datasheet's recommendations, it works reasonably well at 5V single supply too. I've used them on my own Genesis line-out sound mods, where I ran them at 8.45V nominal. https://www.ti.com/lit/ds/symlink/ne5532.pdf Granted I don't ever drive headphones from an NE5532.
For headphones I'd consider an LM4880, an inverting 250mW stereo power amplifier capable of directly driving 8~32 ohm headphones from 5V single supply. It has a completely different pinout from a standard dual op-amp though.
I'd personally use both an NE5532 (or TL972 - note the 9, you don't want the TL072!) and an LM4880: the NE5532/TL972 for the preamp/line out and LM4880 just for the headphones. On both regards it should do much better than the RC4580 can by itself.

Also those electrolytic caps are too close to the regulator; when it heats up it'll shorten the lifespan of those caps, especially when they're mounted underneath a waveblaster card; won't be too much air flow getting to them. 1 cm of space between the caps and the regulator should help extend the life of those caps a lot. (In reality it should be more, but I know how space constrained laying stuff on a PCB gets.)

Fantastic work as always!

Question regarding the PCIMIDI connectivity: Will it use the same board as the PCMIDI board for the MK8330?

thank you all for your kind words and recommendations, we will investigate and add things to the next proto
also I have to comment on the 7805 - it really does not get hot on the card - not only the draw is not much but also copper plane is used as heatsink
we'll see how additions change the design and act accordingly 😀