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my Sega Genesis audio comparison project


derFunkenstein

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I've started to amass a collection of Genesis consoles, and everybody knows that different revisions of the Genesis sound differently from one another. "How differently?" you ask? I'm slowly working on finding out.

 

Using Streets of Rage 2 and some mid-range audio equipment, I'm capturing audio from all the Genesis systems in my collection. So far I've done three comparisons:

 

VA6 headphone jack vs RCA output

VA6 headphone jack vs Sega CD output (which required the headphone passthrough)

VA6 headphone jack vs VA3 Model 2 RCA output

 

Playlist URL: https://www.youtube.com/playlist?list=PLlXTvNagNm4KvMD3XQMNx11uqUxcSt82D

 

Gain is matched and no other processing is done to the audio outside of lining up samples and flipping the phase to make them cancel each other out as much as possible. So far, the VA6 direct from the headphone jack is by far the brightest, meaning it has more high end of the frequency spectrum than the others. It's also got an annoying squeal at 16 kHz that wasn't present in the AV port output or the model 2 VA3.

 

I'll be adding to this as I get time, but to really do this exhaustively I need to buy or borrow more consoles. All I currently have left to do is a pair of model 2's: a VA 1.8 with the Triple Bypass board (designed by db Electronics and produced by Insurrection Industries) and a VA 2.3 that's had a resistor removed to pull up the volume on the PSG channels. I need to get my hands on a VA4 model 2 and a stock VA 1.x model 2 (or a Genesis 3 that uses the same GOAC and a VA7 model 1). I also need to finish recapping my VA2, since the output on that is different than the VA6 (the VA2 has some distortion on loud games, so the gain staging and filtering is different).

 

If you have a Genesis you'd like compared, you could capture the audio at 24-bit / 96-kHz directly from the output and then I can add it to my project. I wish I'd captured my VA2.3 before removing that resistor and then take before/after audio, but I didn't think about it.

Edited by derFunkenstein
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You also need to get a hold of a va3 model 1 because the loud sound distortion that is present on the model 2 is basically corrected on the va3. The va3 is my favored among all the models as I feel it has the best overall stock sound. Having said that, the va2 I have with all the audio modifications in place is what I actually use for all of my videos with Genesis captured audio in them.

 

Might be fun to get some of those recordings and compare them in your analysis as well?

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I'll take anything I can get. Each mono track at 24/96 is around 25-28MB for a minute and a half that it takes to loop through Go Straight. Your VA3 should sound (I think) basically the same as my VA6, because that whole family of VA3-6.8 used the same circuit, it seems. I like it the best of the stock Genesises (Genesii?) that I've owned.

 

The phase inversion process is blowing up my preconceived notions of what's going on. Basically, no two systems cycle at exactly the same rate. The VA1.8 Model 2 with a Triple Bypass board from Insurrection (which I haven't posted yet) oscillates in and out of phase. That one got recapped and may have gotten a new crystal, I dunno. Ben from @iFixRetro did the work. My VA2.3 model 2 runs just a margin-of-error faster than the VA6 model 1, and that's why the phase issues get more prominent towards the end of the song - I lined them up with the kick drums at the end, and suddenly the first half of the song sounds fine.

 

It's just really wild. I thought by now I'd have a feel for what I was trying to figure out when in reality, I'm just starting to scratch the surface.

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No..the va3 does NOT sound like the later models. I've had at least 3 of each come through my hands to be worked on. The va2 and va3 are a full 10db louder than all other models. It is especially noticed if you install RCA jacks off the think directly tied off the 1034 amp chip itself. And yes I know how large they can get. I've only recorded all of my Genesis stuff directly into my SB Zxr at 24bit 96khz. The longest raw wave I have I think is my complete recording of the YM2017 album.

 

Are you strictly using Go Straight from SOR2 as your test sound?

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OK, I've never had a VA3 M1 so I was just going off that thread.

 

Right now I'm just using the one song. It's such a complex tune it seemed like a great test.

 

It is an okay test, but the first SOR had some effects with the instruments that sound different between the model 2s with their embedded YM3438 synth circuit in the main ASIC vs the discrete YM2612 in most of the Model 1 units.

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That's interesting. I'll check it out. I played the original quite a bit this weekend when I wasn't doing dorky stuff like this.

 

Now that I've had my triple bypass board back for a week now and I've played a lot of Genesis games (as opposed to Sega CD games, because I was finishing Shining Force CD), I think it sounds amazing. My home theater in the living room thumps. Games that never sounded that great to me (NBA Jam, for instance) sound decent for what they are, and games with iconic soundtracks just absolutely rip. Earthworm Jim's first level, Sonic 3's Ice Cap zone, and Castlevania Bloodlines sounds great.

 

To be fair, the also sound great on the VA6. I don't have a totally stock ASIC-equipped Genesis to compare with right now. What I really need to get (but would have to get another VA1.8 to do) is a before and after with that chip. I can't believe I didn't take some recordings before sending it off.

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Triple bypass board?

 

Also did you know that Bloodlines soundtrack doesn't even use all the channels? I don't believe it uses any PSG at all. Point being, the soundtrack could have been made even more amazing on stock hardware had Konami invested into it more.

 

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Ahh that explains it. It is for the model 2 and 3 systems. I only tend to keep up to date with Model 1 mods so I thought it was something along those lines. But I have been installing FBX's M1 Mini Mega amp for the model 1. But again we can't really use these modded consoles for your comparison. I do have 2 model 2 units that are still 100% stock but I've no idea which models they are as I've never opened them up to work on them.

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Yeah, even for the VA7 you're better off doing the Mega Amp and just lift the composite subcarrier pin to fix RGB, if you're so inclined. You could probably even put a toggle switch in there, if you're inclined to turn composite back on.

 

One bad thing about this triple bypass is there's no composite video. There's a jumper that I *think* is for composite video, but I'm afraid to bridge it since I don't REALLY need it.

 

Every other model 2 I have displays jailbars even in the composite signal on my 27" Trinitron CRT (pictured in the videos).

Edited by derFunkenstein
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  • 4 years later...
On 1/19/2019 at 1:15 PM, derFunkenstein said:

I'll be adding to this as I get time, but to really do this exhaustively I need to buy or borrow more consoles. All I currently have left to do is a pair of model 2's: a VA 1.8 with the Triple Bypass board (designed by db Electronics and produced by Insurrection Industries) and a VA 2.3 that's had a resistor removed to pull up the volume on the PSG channels. I need to get my hands on a VA4 model 2 and a stock VA 1.x model 2 (or a Genesis 3 that uses the same GOAC and a VA7 model 1). I also need to finish recapping my VA2, since the output on that is different than the VA6 (the VA2 has some distortion on loud games, so the gain staging and filtering is different).

 

If you have a Genesis you'd like compared, you could capture the audio at 24-bit / 96-kHz directly from the output and then I can add it to my project. I wish I'd captured my VA2.3 before removing that resistor and then take before/after audio, but I didn't think about it.

I know this topic is old, But I got a question. I have a VA 2.3 Genesis Model 2, Which resistor did you remove that brings up the PSG?

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