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

[retrogamer343]

Sorry no update on the model 3 yet. I just moved last week and I'm still trying to get all unpacked. As soon as I can I will get some pics put up of the genny 3 board I have and see if we can get this figured out.

[Drakon]

Does the model 3 use the asic 3438?

[Drakon]

New demonstration video:



This's comparing a stock va6 model 1 to a crystal clear audio modded va7 model 1.

[BlockABoots]

Done a Few Comparisons of my MD2 VA1 with original audio and then the same console again but with the CCAM carried out on it.....

[Drakon]

Sonic 2 longplay on my va7 model 1. Audio is a crystal clear audio mod with adjusted low pass fitlers, video is s-video from my s-video modded 32x.

[mvsfan]

i did the ccam mod to a va7 and everything worked fine except the volume was way too low.

so....... I hooked up a PAM8403 amplifier after the ccam, and it sounds good at lower volume but when i turn it up it pops loudly and consistently almost like the ic power is cutting out.

i guess i need a seperate power supply for this. my thoughts are the voltage regulator isnt providing enough power to power the ccam and the 8403.

anyone else have any ideas? mabeye im wrong.

how much power can that voltage regulator provide?

[MEGADRIVE Jeroi]

i did the ccam mod to a va7 and everything worked fine except the volume was way too low.

so....... I hooked up a PAM8403 amplifier after the ccam, and it sounds good at lower volume but when i turn it up it pops loudly and consistently almost like the ic power is cutting out.

i guess i need a seperate power supply for this. my thoughts are the voltage regulator isnt providing enough power to power the ccam and the 8403.

anyone else have any ideas? mabeye im wrong.

how much power can that voltage regulator provide?

Hello, it happens because CCAM uses biasing to bias output arraund 2.5v and the sound is crystal clear. How ever if you add another amp with only 5v dc to 0 you will end up cutting top of the signal away and get horrible sound. the way to make louder is to change amplifier resistors in CCAM but thats hard because I think it uses noninverting amplify.

Better solution is to build GOAC which uses inverting amplify where one can amplify so much that it even sound too loud on tv with just one resistor change on amp.

[mvsfan]

Hello, it happens because CCAM uses biasing to bias output arraund 2.5v and the sound is crystal clear. How ever if you add another amp with only 5v dc to 0 you will end up cutting top of the signal away and get horrible sound.

im not understanding why its popping though only when i turn the amplifier pot up loud. it works fine when the amp is on low volume.

i guess what i dont understand is why is the volume so low to begin with.

whats the difference between hooking this little amp up in the genesis, and hooking the genesis up to a pioneer sound system? why doesnt it pop when the ccam goes straight into a sound system?

but even with the sound system it just doesnt get loud enough.

i dont get it.

[mvsfan]

Sofar, my VA6 wins. im not impressed with this mod yet.

[villahed94]

Got a quick question regarding CCAM and the Nomad.
I traced the FM audio lines from the ASIC, and I found that they go through the ribbon cable and then on the main board it goes through a 0.1 uf cap before entering the 315-5684 amp.
So Where should I get the signal? Before or after the cap?
Thanks

[MaxWar]

Got a quick question regarding CCAM and the Nomad.
I traced the FM audio lines from the ASIC, and I found that they go through the ribbon cable and then on the main board it goes through a 0.1 uf cap before entering the 315-5684 amp.
So Where should I get the signal? Before or after the cap?
Thanks

Funny how timely that post of yours seems to me. I am as of right now Installing a CCAM in a genesis for the first time and was trying to find exactly where and how to connect it.
My guess would be to disconnect whatever sound circuit is already there and connect right at the ASIC output but I cannot find confirmation for this anywhere

[TmEE]

All of original sound circuit must be disconnected in its entirety, or there's gonna be garbled or otherwise bad sound.

[MaxWar]

Thanks a bunch Tiido, Thats what I call a fast response.

[villahed94]

OK. Thanks. I will grab the sound from the point before the cap after removing the cap.

[MaxWar]

Ok, another question. I installed the CCAM and it works, but I find my signal to be a bit noisy. I can sort of hear the Genesis processing through the sound, It does it with a stock genesis too but it seems worse now. (or maybe it was simply hidden by the distorting sound before )

Then I found this picture here, my genesis is a VA1 so it applies.



What intrigues me is the (Make solder bridges) part. At the moment there are two resistors (R73) and (R72) in those spots, respectively connecting to AUSS and SOUND on the ASIC. What would be the effect of taking out those parts and making a bridge instead?

Also, Tiido, I think maybe linking this picture in the first post of the thread could be helpful to people.