There's zero proof that the Genesis model 1 produces better sound than model 2

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05-07-2009, 07:23 PM
Ace

If you find a Genesis 2 that has a shorter metal plate under the system through the air vents, those are the VA3/VA4 versions with the clean audio. Older Model 2s will also have super-shitty video; it's blocky, pixellated as all hell, blurred, and has the same line noise problem as a Top-Loader NES, but to a lesser extent(not as many vertical lines visible). I did notice something, though: if you take a VA0-VA1.8 Genesis 2 and hook it up to a Sega CD, if you use the sound output from the Sega CD instead of the Genesis, the sound is filtered, though the quality doesn't improve.

Allow me to explain in detail the sound problem: while every Genesis has a YM2612 in different formats, either integrated within one of its chips or as a separate chip, it's not the cause of the nasty audio. As mentioned before, it has to do with other parts of the circuitry. The problem lies within the sound amplifier. For whatever reason, when the Genesis Model 1 got the VA7 motherboard in it, the sound amplifying circuitry Sega used caused the sound quality to drop drastically, to the point where it would distort some of the sound. To make matters worse, it also induced static. Some Genesis 2s made in China actually FURTHER EXACERBATE the problem by changing some things around in the sound circuit that further distorts the sound to the point where some low-pitched sounds are output as squeaks. Here's a rundown on the sound quality plus a general description of the sound amplifying circuitry:

-Genesis Model 1 with High Definition Graphics(motherboard revision VA0-VA6, contain EXT port): these use a discrete YM2612 with a sound amplifier that filters the sound to give it more bass. Sound quality is exceptional.

-Genesis Model 1 without High Definition Graphics(VA6-VA7 motherboard revision): some of these are identical to the Genesis Model 1 with High Definition Graphics, but as mentioned before, VA7 motherboard revisions contain a sound circuit that drastically lowers the quality of the sound output and induces static. The VA7 revision uses a YM2612 integrated within an ASIC on the motherboard.

-Genesis Model 2 with full motherboards(revisions VA0-VA2): VA0, VA1 and VA1.8 Genesis 2s use a YM2612 integrated within an ASIC like the VA7 Genesis Model 1 and use the exact same super-shitty sound circuit found in there. Some VA1.8s, as previously mentioned, tend to distort the sound even more, which are made in China. VA2s have a discrete YM2612, which sounds like a Genesis Model 1 with High Definition Graphics, but with less bass. The big problem with this Genesis 2 is in its tuning of the sound outputs. The YM2612 is too loud compared to the other sound channels: Genesis PSG, Sega CD PCM/CD-DA, and 32X PWM. Not only that, the PSG sound channels are out of tune, with some sound channels being louder or quieter than their supposed to be, which may be as a result of using a different sound amplifier than the Genesis Model 1 with High Defintion Graphics.

-Genesis Model 2 with 3/4 motherboards(VA3 or VA4 revision): These use a revised sound circuit that sounds almost like the High Definition Graphics Genesis Model 1, but with MUCH less bass and a much lower decay rate(you hear the sound channels echoing less). Its quality is the best out of all Genesis 2s. These use a YM2612 integrated in an ASIC.

There's a common trend among the ASIC-based YM2612 in which they have a lower decay rate than the discrete YM2612, and it does actually output slightly clearer sound than the discrete YM2612 when properly amplified.

You'd be better off with a High Definiton Graphics Genesis Model 1, though. Nothing can beat its high-bass sound, except TmEE's Audio Mod circuit for the VA7 Genesis Model 1 and VA0-VA1.8 Genesis 2 for some(I personally prefer high-bass sound).

Quote:

Originally Posted by nathanallan

One of my I's has developed static in the sound. Not sure what happened, it was working great a littel while ago and I play it pretty often.

Nathan, you mind taking a picture of the back of that Genesis Model 1? I can diagnose your static problem that way.
05-07-2009, 07:42 PM
gamegenie

Thanks Ace. You've provided the most thorough explanation of the differences.

I wish there some way to tell what type of model 2 I have without having to open it up.
05-07-2009, 09:42 PM
Ace

There is. Flip it over and look through the air vents. You should also check for wires running from the cartridge slot to other locations on the motherboard. If you have a digital camera, take a picture of your Genesis 2's underside and inside the cartridge slot so I can properly identify them. Otherwise, just give me a description of what you see.
05-07-2009, 10:23 PM
gamegenie

Quote:

Originally Posted by Ace

There is. Flip it over and look through the air vents. You should also check for wires running from the cartridge slot to other locations on the motherboard. If you have a digital camera, take a picture of your Genesis 2's underside and inside the cartridge slot so I can properly identify them. Otherwise, just give me a description of what you see.

here's the bottom of my Genesis 2:
05-07-2009, 11:07 PM
kool kitty89

Quote:

Originally Posted by Ace

There's a common trend among the ASIC-based YM2612 in which they have a lower decay rate than the discrete YM2612, and it does actually output slightly clearer sound than the discrete YM2612 when properly amplified.

You'd be better off with a High Definiton Graphics Genesis Model 1, though. Nothing can beat its high-bass sound, except TmEE's Audio Mod circuit for the VA7 Genesis Model 1 and VA0-VA1.8 Genesis 2 for some(I personally prefer high-bass sound).

Actually TMEE said you can have the Bass with the modded ASIC models too, you just need to use a filter:

Quote:

Originally Posted by TmEE

To have strong bass (and less crisper sound) from the mod is just the matter of adding couple of low pass filtering caps on audio out area...
05-07-2009, 11:50 PM
Ace

Except that no matter how many capacitors I added, and no matter what their capacitance was, I just couldn't get the Genesis Model 1's high-bass audio using TmEE's Audio Mod circuit. What capacitance is needed?

@Gamegenie: Already, that's a bad sign. You have a full motherboard Genesis 2. To know for sure if it's a pile of crap VA0-VA1.8 board or the better VA2, I need a picture of the cartridge slot held open.
05-08-2009, 12:22 AM
gamegenie

Quote:

Originally Posted by Ace

@Gamegenie: Already, that's a bad sign. You have a full motherboard Genesis 2. To know for sure if it's a pile of crap VA0-VA1.8 board or the better VA2, I need a picture of the cartridge slot held open.

Use the attachment feature, please.

-Melf
05-08-2009, 10:39 AM
TmEE

That is a VA0 MD2 :)

Quote:

Originally Posted by Ace

Except that no matter how many capacitors I added, and no matter what their capacitance was, I just couldn't get the Genesis Model 1's high-bass audio using TmEE's Audio Mod circuit. What capacitance is needed?

I had ultr@ strong filtering happening with small ceramic caps with 104 on them (you can find those around any chip...).
05-08-2009, 11:17 AM
gamegenie

Quote:

Originally Posted by TmEE

That is a VA0 MD2 :)

I kind of had a feeling I that I had the crappy Genesis model 2 http://i163.photobucket.com/albums/t...iley-drunk.gif

On the plus side, I'm looking forward to getting my HD Graphics Genesis, I'm excited to hear how my games will sound on it. :D
05-08-2009, 11:41 AM
TmEE

VA0 is amonst the models that is guaranteed to sound best after modding though :)
05-08-2009, 12:35 PM
Devil N

I've already established that my MD2 has a VA1 mobo (opening up the console makes it pretty definitive), so apparently I also got the short end of the stick when it comes to sound circuitry. But seriously, the chain is as weak as the weakest link, and the weakest link in my setup is definitely the TV that my MD2 is hooked up to. So I could buy or mod whatever I want, but I don't think the sound would actually improve. Nor do I see myself hooking up my MD to a stereo system. To be honest, I simply don't care that much, since it's the little imperfections that make the MD experience so charming to me.
05-08-2009, 09:57 PM
kool kitty89

Is your system hooked up to the TV through RF? That's denfinitly the worst sound and picture wise, though you'd still probably notice a bit of an improvement with the audio mod.
05-08-2009, 10:25 PM
gamegenie

Quote:

Originally Posted by kool kitty89

Is your system hooked up to the TV through RF? That's denfinitly the worst sound and picture wise, though you'd still probably notice a bit of an improvement with the audio mod.

composite AV.
05-09-2009, 06:50 AM
Devil N

Quote:

Originally Posted by kool kitty89

Is your system hooked up to the TV through RF? That's denfinitly the worst sound and picture wise, though you'd still probably notice a bit of an improvement with the audio mod.

RGB SCART, the best I can get. There are limits to the number of imperfections I'm willing to put up with, especially if they are so easily fixed. :p

But that TV I was talking about, it has some kind of dynamic range compression going on that simply can't be shut off. Whenever the sound gets loud (e.g. whirring sounds, explosions, music swelling up), the entire volume goes down and all the other sounds are drowned out. Another example, the thick bass in Streets of Rage's stage 6 music is completely inaudible, but what happens is the other instruments become softer as well. It sounds terrible to be honest, but right now I can't do anything about it.

I should be getting a different CRT TV in a few months time, which will hopefully sound better (I don't see how it could be any worse). Still, TV speakers never produce the best sound imaginable, but they do produce the most authentic sound for me, since I'm looking for the same Sega experience I had when I was younger (minus the RF signal, that is :)).
05-09-2009, 08:33 AM
retrospiel

There are some great 80s CRTs with awesome sound. My 80s Nokia, although mono, got quite an impressive warm sound and it is definitely good enough to watch movies with it. Before that, I had a 70s Grundig with stereo but it didn't take RGB (I used my VCR for the RGB to composite conversion) and sadly it broke two or three years ago.

Quote:

Nor do I see myself hooking up my MD to a stereo system.

Personally I use an RGB-SCART switch box that got an RCA cinch audio out which I send to my 70s Pioneer amp. To get my model 1 to output in stereo I use a custom RGB-SCART cable (about €10 at ebay) which grabs the audio from the headphones out instead of the AV port.

Quote:

But seriously, the chain is as weak as the weakest link, and the weakest link in my setup is definitely the TV that my MD2 is hooked up to. So I could buy or mod whatever I want, but I don't think the sound would actually improve.

If you got a good sound source and bad speakers, the good sound will sound bad. If you got a bad sound source and bad speakers, the sound will sound twice as bad.

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