Can you put in only one SAA1099? I imagine hearing that some of the voices sound right

Yeah if i trade them sound changes.. one sounds really weird, the other a bit lesser..

Clock and co is fine.
But the Amp of the Card is ehm very noisy and needs better Power Supply 😀

Yes, the card is extremely noisy. That's one big drawback. The SnarkBarker is much better in that regard.

Both CMS Chips are damaged.. it works now, and CMS Sounds Fantastic

i replaced C21 with 470uf, reduces Noise a bit.
100uf is little bit optimistic.
Much better would be to add a 7809 and supply Amp from 12V line.

root42 wrote:

Yes, the card is extremely noisy. That's one big drawback.

Yes, SAA1099 has open-collector outputs which we pull-up to +5V power rail with 1K resistors and collect all the interference and digital noise from all computer. In my CMS-clone design i modified circuit, i make new "analog" +5V path with help 78L05 linear regulator from +12V, as is done in many sound cards. The interference and noise is all gone!

Secondly, i power up ampliefier from +12V rail with help two 1N4001 diodes, voltage drop on them is about 2-3 volts, so TEA2025B powered at ~9 volts. Also diodes filter the variable component.

Well that looks like a mod I could try to do...

Tronix wrote:

Yes, SAA1099 has open-collector outputs which we pull-up to +5V power rail with 1K resistors and collect all the interference an […]
Show full quote

root42 wrote:

Yes, the card is extremely noisy. That's one big drawback.

Yes, SAA1099 has open-collector outputs which we pull-up to +5V power rail with 1K resistors and collect all the interference and digital noise from all computer. In my CMS-clone design i modified circuit, i make new "analog" +5V path with help 78L05 linear regulator from +12V, as is done in many sound cards. The interference and noise is all gone!

Hello and good evening!
Nice work, I would have done it the same way.
However, as it seems, there's some more required for an accurate 78xx base configuration.
Some caps (2x) and a diode are highly recommended, as it seems.

Source:https://www.mikrocontroller.net/topic/337533

Jo22 wrote:

Some caps (2x) and a diode are highly recommended, as it seems.

Caps - yes, recomended, especially on the output, something like 10uF + 0.1uF ceramic + 0.01uF ceramic . Diode - i think no, its short-circuit reinsurance in very old 7805 regulators with high unstable power source like AC/AC transformer or onboard vehicle electrical system. Modern LDO (low drop-out) regulators like 78L05 have build-in short-circuit protection, thermal protection, output transistor protection and other "protections", so no need more external components.

Some Progress:

So far.. i will order the PCB soon 😀

Tronix wrote on 2019-12-14, 18:52:

Jo22 wrote:

Some caps (2x) and a diode are highly recommended, as it seems.

Caps - yes, recomended, especially on the output, something like 10uF + 0.1uF ceramic + 0.01uF ceramic . Diode - i think no, its short-circuit reinsurance in very old 7805 regulators with high unstable power source like AC/AC transformer or onboard vehicle electrical system. Modern LDO (low drop-out) regulators like 78L05 have build-in short-circuit protection, thermal protection, output transistor protection and other "protections", so no need more external components.

One of the main goals is to keep the 7805 from oscillating. If it starts to oscillate, it may heat up unecessarily.

Edit: The diode is optional, yes.
It may also act as a shunt diode here.
Anyway, I go by the old saying "If you do something, do it right." 😇

Edit: I forgot.. 78 series regulators don't really like AC input.
In fact, I killed one in a famiclone by applying reverse polarity by accident (they often have negative center pin) .

Since then, I always add a diode (1N4007 etc) in my own stuff.
Also, for a home made PSU, a fuse (two actually) and some form of bridge-rectifier is recommended. It also might be more efficient than a single diode.

Edit: Oh, and I always use heat sinks..

Edit: Typos fixed.

matze79 wrote on 2020-09-23, 13:59:

Some Progress:
mus2020.jpg

So far.. i will order the PCB soon 😀

Thanks for the news, the circuit board looks good! 👌

PCBs are at customs, waiting for clearance.

I hope it works as expected!!! 😀

got PCB... customs took forever!

matze79 wrote on 2020-12-10, 17:52:

got PCB... customs took forever!

blub.jpg

Are you selling these PCBs? And/or is the design open source?

Not yet, there a few Flaws inside which need fixing.
i may have some prototype pcbs left which i can give away, i don`t need 10.
PCB is too thin (1.4mm, should be 1.6mm did forget check box during order), PCB is bit too short on the Rear, CMS Detection does not work at all.
Tested Sylpheed, Bad Blood, Monkey Island and Paku Paku.
Bad Blood sounds weird, CMS Demo Disks does not detect it.

Monkey Island, Sylpheed and Paku Paku sound good!

Due to transition to SMD i guess some timing is off.
As shock_ suggested i will try different variant of 74 series (ls/hct) maybe this will fix the issues.
But also good News, no Bus Noise, no weird HDD access Sounds etc. 😀

Need to make transition to KiCad too, means redraw the design 😀

There is a Error in the Card Design, the R1 Resistor is 1k and could cause missing Notes.
If using other Logic ICs then LS Series.
It should 4.7kOhm (Thx Scorp).

What i not understod yet is why D7 Dataline in this design is connected over 1k to Ground but D0 to D6 to VCC.

Hello everyone!

Recently I discovered this thread, and decided to spend some money and time building this CMS clone. Now I want to share my experience, hoping it could be useful for anyone.

First of all, I want to thank Sergey and Tronix from vcfed for reversing the logic on the original CMS card, and Veovis for creating and sharing the initial PCB design.

I made the following changes over the PCB initial design:

• Modified the potentiometer layout to fit a common RK097G, which can be easily found on Aliexpress.
• Modified the potentiometer connection to the more common way of outputting the signal trough the central tap.
• Added 1k resistors on the gain loop of the TEA2025 amplifier. This reduces the gain from 200 (46dB, which is crazy) to 9.5 (19dB), as the original CMS card (the 1k resistors can be seen on pictures of the original card).
• A lot of cosmetic changes: moved some components and traces, texts, logo, component labels, etc.
• And last, but most important of all, added a 78L05 linear regulator to generate a clean +5V rail to feed the SAA1099 output pull-ups and reference current inputs. This completely eliminates the annoying power supply interference, and gives very good sound quality, with the noise level expectable for an almost 40 years old hardware.

This is a picture of the assembled card:

If anyone is interested in seeing the card in action, I have a video of it running the Monkey Island intro, and a direct recording trough the line input o a modern PC, to better appreciate the sound quality.
https://www.youtube.com/watch?v=mu7Xl_ZV0GE
https://www.youtube.com/watch?v=Ur-zXDIUB3U

I also tested the utils and player from the CMS driver disks, and a handful of games from the Mobygames CMS compatible list. Everything detects the card and sounds correctly (comparing with DOSBox emulation).

I have four spare PCBs, I can give them just for the manufacturing costs plus shipping cost (don't want to make bussinnes). If anyone is interested, PM me.

davidmorom wrote on 2022-11-29, 18:07:

Hello everyone! […]
Show full quote

Hello everyone!

Recently I discovered this thread, and decided to spend some money and time building this CMS clone. Now I want to share my experience, hoping it could be useful for anyone.

First of all, I want to thank Sergey and Tronix from vcfed for reversing the logic on the original CMS card, and Veovis for creating and sharing the initial PCB design.

I made the following changes over the PCB initial design:

• Modified the potentiometer layout to fit a common RK097G, which can be easily found on Aliexpress.
• Modified the potentiometer connection to the more common way of outputting the signal trough the central tap.
• Added 1k resistors on the gain loop of the TEA2025 amplifier. This reduces the gain from 200 (46dB, which is crazy) to 9.5 (19dB), as the original CMS card (the 1k resistors can be seen on pictures of the original card).
• A lot of cosmetic changes: moved some components and traces, texts, logo, component labels, etc.
• And last, but most important of all, added a 78L05 linear regulator to generate a clean +5V rail to feed the SAA1099 output pull-ups and reference current inputs. This completely eliminates the annoying power supply interference, and gives very good sound quality, with the noise level expectable for an almost 40 years old hardware.

This is a picture of the assembled card:
cms.jpg

If anyone is interested in seeing the card in action, I have a video of it running the Monkey Island intro, and a direct recording trough the line input o a modern PC, to better appreciate the sound quality.
https://www.youtube.com/watch?v=mu7Xl_ZV0GE
https://www.youtube.com/watch?v=Ur-zXDIUB3U

I also tested the utils and player from the CMS driver disks, and a handful of games from the Mobygames CMS compatible list. Everything detects the card and sounds correctly (comparing with DOSBox emulation).

I have four spare PCBs, I can give them just for the manufacturing costs plus shipping cost (don't want to make bussinnes). If anyone is interested, PM me.

Just wanted to say, I got one of these from davidmorom and it is a beautiful card! I can't wait to put it together! 😀

Me too 😁

A lot of people leveraged the original design to make improvements and did not share the PCB design. Note the mods where possible thanks to the MUS-1099 design being open.
@davidmorom your PCB can be the new MUS board standard, can you consider sharing it? Otherwise it's reinventing the wheel over and over again.
(I don't think SMD based designs are what most people want, this project needs to keep being beginner friendly IMHO)
Thx!

Hi @gerpux, thanks for your interest in my modifications of the original board!

I leave here the Eagle project and the gerber files, just in case anyone is interested in sending them for manufacturing, or making further improvements.