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

[Ace]

Well, that explains everything. But I'd like to know how you can amplify the PSG sound channel more on your circuit. What part(s) need to be changed in order to amplify the PSG sound channel more?

[TmEE]

You will have to decrease the 1.5Kohm resistors on the PSG transistor outputs... why do you need louder PSG ? The level is more or less exact same as what a no TMSS MD1 does.

[Ace]

For the MegaDrive clones that have horrid sound output. I was going to try out your new Audio Mod circuit on the GN Twin, since the prototype circuit caused some straining, even though it was less than the straining from the stock sound circuit.

[Afcs46]

One question. The chip MC4558 can be used instead the 4558d?

[TmEE]

Most likely yes.

.....and comparsions

MD2 CCAM 1.0 -> http://www.fileden.com/files/2008/4/21/1876835/TF4.ogg
MD2 stock -> http://www.fileden.com/files/2008/4/...35/TF4_MD2.ogg
no TMSS MD1 (HiDef) -> http://www.fileden.com/files/2008/4/...35/TF4_MD1.ogg

[Christuserloeser]

MD2 CCAM 1.0 -> http://www.fileden.com/files/2008/4/21/1876835/TF4.ogg
MD2 stock -> http://www.fileden.com/files/2008/4/...35/TF4_MD2.ogg
no TMSS MD1 (HiDef) -> http://www.fileden.com/files/2008/4/...35/TF4_MD1.ogg

Awesome.

A little TOO clear for my tastes. Metal Squad doesn't really sound all that great with all the bass removed.

Like TmEE said, it's really just the high frequencies restored. That means that on the same stereo setup with the same volume and same EQ settings it will give you the impression that it would sound cleaner but with the bass gone. However, the bass is actually still there so you could just use your amp's EQ to shift the balance more towards a deeper, more bass driven sound. - "Restoring" high frequencies on the other hand doesn't work like that, they're either there or they are filtered out (like in a stock MD1 or even worse: a stock MD2), so TmEE's mod is the much better choice for everyone that got a decent audio setup at home.

[Ace]

Wow... I completely forgot about just how clear Audio Modded MegaDrive IIs sound compared to pre-VA7 MegaDrive Is. Still, I'm going to adjust the circuit to try and get it to MegaDrive I bass levels.

@Christuserloeser: I don't have an amp; the sound is run straight into my TV's Stereo speakers, and my TV's sound setup is just dumb(you can't adjust the amount of bass/treble).

By the way, TmEE, I should soon be able to send you a VA7 MegaDrive. They're everywhere here; practically every Genesis Model 1 I find here is a VA7.

[TmEE]

Wow... I completely forgot about just how clear Audio Modded MegaDrive IIs sound compared to pre-VA7 MegaDrive Is. Still, I'm going to adjust the circuit to try and get it to MegaDrive I bass levels.

@Christuserloeser: I don't have an amp; the sound is run straight into my TV's Stereo speakers, and my TV's sound setup is just dumb(you can't adjust the amount of bass/treble).

Take a 0.1µF ceramic cap and ~20Kohm potentiometer, put them in series and use it insead of the 0.022µF cap, you can easily adjust filtering level that way

By the way, TmEE, I should soon be able to send you a VA7 MegaDrive. They're everywhere here; practically every Genesis Model 1 I find here is a VA7.

That sounds lovely

[Afcs46]

Most likely yes.

.....and comparsions

MD2 CCAM 1.0 -> http://www.fileden.com/files/2008/4/21/1876835/TF4.ogg
MD2 stock -> http://www.fileden.com/files/2008/4/...35/TF4_MD2.ogg
no TMSS MD1 (HiDef) -> http://www.fileden.com/files/2008/4/...35/TF4_MD1.ogg

OMG, this sounds so cool... I will see if I can do this thing.

[clamchowder01]

If you rip music off the Sega CD, will it sound better with your crystal audio mod?

[TmEE]

There's no meaningful difference between recording of a CDDA track through the mod and direct lossless CD rip. You cannot get better sound than original unless I add some equalizer or something to the mod itself, but that would increase component count well over 100, perhaps even 200 when I want multiple bands and HiFi quality stuff. That's a bit of an overkill :P

[Joe Redifer]

Your Thunder Force 4 for MD1 sounds worse and more muffled than Thunder Force 4 recorded from my Genesis 1 (non-TMSS).

[Christuserloeser]

I'd love to hear some recordings of your non-TMSS Genesis 1. I have a TMSS Genesis 1 that I currently use for recording.

Can't wait until I get CCAM'd hw from Tiido.

[TmEE]

That MD1 I used is my primary use VA4 PAL no TMSS MD1... I guess there's quite some part variation going on, thus differences in sound quality.....

[Ace]

It's funny: my VA3 pre-TMSS Genesis 1s both have MORE bass than TmEE's VA4 MegaDrive 1. But my Japanese VA5 MegaDrive also has more bass than that. TmEE, did you use your computer's Line In to record your sound clips?

I also have a question: how would I go about making the decaying from the YM2612 more audible using the CCAM? On the prototype circuit I built, the decaying of the YM2612 is inaudible, and I would like one of my Genesis 2s to sound exactly like the Genesis 1 using your circuit, and I will also get myself a second VA7 Genesis 1 to apply the circuit to so that I can make it sound like all other Genesis 1s with superb clarity and high bass.