Crystal Clear Audio Mod for Sega Mega Drive 2 & Genesis 2, version 1.0

[retrogamer343]

I forgot to mention to those of you who didn't know but these boards are made literally in my garage and not sent out to a fab house. This is one of the reasons that the board is not as small as I would have liked. While thinking about size and layout I also had to think about things like distance from parts, distance between traces and trace width. There are a lot of factors that go into making a board at home that you would not necessarily think about if you were sending a design out to a fab house. My goal was not at all to make the smallest board I could but to make a board that was cost effective, easy to build, and easy to install. And I think I have done that.

[pinkwasa]

I <3 you - not important what others say

[retrogamer343]

Hey guys I need a little help getting the ccam installed into a va7 board as well as a genny 3. I have the connections on the va7 figured out but the psg volume is lower than the rest of the music. Not sure if changing a resistor value will help with this. If anyone is interested in supplying the board members with some install diagrams I will send you a free ccam board. I can also supply some board pics if needed.

[TmEE]

You have something still connected if the PSG volume is lower.

[retrogamer343]

That's what I thought but I can't see where. I traced psg from the pin all the way to the first component, a capacitor. I removed that cap and connected psg to the neg side. There do not seem to be any components connected anywhere. I will take another look though.

[TmEE]

The PSG is only at the right level when it straight from the ASIC. There is a resistor on the line somewhere, like in MD2.

[retrogamer343]

So there are a few people who want to purchase a ccam pcb from be but they are new members and they are only allowed 1 pm at a time so there inbox is already full. If you are one of those members please use my email address to contact me. And for anyone else interested in one of these smd boards I have a few ready to go.

[Drakon]

I'm placing my order for one. Just working out the details over pm.

[BlockABoots]

Ok I have one of retrogamer343's PCB's which I've had since about JAN time, but his week I'm actually gong to get around to installing the damn thing in my MD2! But before I do that I want to take some audio samples of the vanilla MD2's audio, I have a Micomsoft PCI capture card that I'll be using to capture these audio samples.

Now my question is I have about 3-4 different audio sampe rates I can chose in the capture software, which sample rate is best to select, one that is the actual MD2's sampe rate (what is it?) or a higher sample rate for a fair test?, and also once I fit the ccam inside the MD2 what sampe rate should I use then for a far comparison?.

If members could give me a good range of games to use for this test, let's say 5 games then that wold be great.

Also is there a official diagram for install retrogsmer343's PCB inside a MD2??

[retrogamer343]

Here is all the installation info people should need when installing the ccam with my smd board:
http://retrotimegames.com/ccam.html

I'm still working on the genesis 3 diagram. Unfortunately the only system I have to test on is very different than any others I've seen so I am looking for a different version board. Sorry BlockABoots I can't help you with your other questions. Hopefully someone else on the board can help out.

[BlockABoots]

Here is all the installation info people should need when installing the ccam with my smd board:
http://retrotimegames.com/ccam.html

I'm still working on the genesis 3 diagram. Unfortunately the only system I have to test on is very different than any others I've seen so I am looking for a different version board. Sorry BlockABoots I can't help you with your other questions. Hopefully someone else on the board can help out.

You might actually have the same gen3 board I have, what revision number is it?

On your site I notice it only mentions VA0, 1 & 1.8 for the mod what about other revision boards?. Also what's the best location to fit the PCB, and fitting it.....just use hot glue on the underside?

[TmEE]

The PCB should be as far as possible from anything on the main board if you want minimal interference. Worst spot possible is the big ASIC, second worst are the VRAM chips or the single VRAM chip on later models.

[Drakon]

I got the mini pcb and wired it up. One of the low pass filter capacitors was only soldered on the one side so it wasn't connected making one channel completely unfiltered throwing the balance completely off. I fixed this mistake on my own, I also pointed out a mistake in the schematic. Really before shipping these pcbs out I recommend testing each channel individually to be sure they both sound correct and balanced.

Am I happy with this product? yes. I'm glad someone took the initiative to do it right. I hope future pcbs will be tested more thoroughly so people don't get pcbs that aren't completely soldered causing the audio quality to not be correct.

[Drakon]

A question about the ccam circuit. When wiring it into a va7 model 1 will it sound the same as the va0 / 1 / 1.8 model 2s?

[madmax2069]

A question about the ccam circuit. When wiring it into a va7 model 1 will it sound the same as the va0 / 1 / 1.8 model 2s?

This is the only video I found of a va7 with a ccam installed

www.youtube.com/watch?v=DTsnbgVHCuo

There's probably better examples out there then this.