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-^Cro§Bow^-'s Hardware Videos - A genesis va3 Model 1 with proper DAC


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So the other night I tackled a hardware upgrade that I had seen mentioned in a youtube video that seemed really interesting. It was a video where a another retro gamer and hardware modder was showing his latest modification using a Yamaha 3438 discreet synth chip to produce the music and sounds in place of the stock Yamaha 2612 that came with the model 1 genesis units. The advantage of doing this was that the 3438 was essentially pin compatible but featured a true 8-bit DAC within it and better overall stereo separation and some improved instrumentation. In fact I've heard that the yamaha 3438 was used in Sega's arcade machines BITD. The video had music samples at the end to demonstrate the enhanced audio and clarity and it was pretty amazing! You also have to realize that wile the 3438 is essentially pin campatible, it does use different timings and logic from the 2612 that prevent it from being a drop in replacement. So to make it work you have to piggy back it off the 2612 in a way that the 2612 handles the timing and logic of the music passing it to the 3438 to produce the actual music and sound. Also the model 2 Genesis and variants from that, use the 3438 synth embedded in the logic of the all in one Sega ASIC that came about in these machines. So technically, the model 2 and above variants should have the benefits of the 3438 already, but due to very poor audio amp and mixing circuits in those variants of the genesis...it sounds worse than the 2612s used in the original model 1 HDG Genesis systems.

So we fast forward about a year from my viewing all of this and I decide to give this a try for myself on my AV modded Genesis 1. I purchased the 3438 (A pair of them actually since you can always get two for twice the price...), the resistors and caps needed to perform the mod. And near as I can tell, I was successful in doing this on my Genesis va3. I've been making quite a few sound sample recordings of my own directly from my gensis's RCA ports I added to it. The audio is really clear on many of the instruments and especially noticeable on drums. But, there were also quite a few games that took advantage of the semi flawed original 2612's architecture to make the games sound the way they did that is lost in the process. For me the biggest change is that some instruments now come out way stronger and too loud compared to the other voices on many songs. In many cases this actually sounds better but in others it sounds off because those voices weren't as noticeable before and hence might have had odd audio tricks they were using that blended well originally, but now stand out way too much.

The two games I've tested so far that have had the largest negative impact with this mod, has been with some music from Steets of Rage 2 and several tracks from Gunstar Heroes. However, the SOR2 tracks that seem affected by the changes, do NOT appear to actually play in the game themselves? I hadn't noticed this before because the audio was essentially the same. Now that I know what tracks sound off (Because you can really tell when you hear them), it was interesting to me that I never actually heard them in a play through of the game itself? I assume these music tracks were unused tracks and perhaps this is the reason for them sounding off. I don't know. I will try and get the SOR2 tracks I did and the Gunstar Heroes tracks upped to youtube when I can hopefully tonight.

In the meantime, most tracks sound pretty amazing and it is more interesting to think what might have happened had the Genesis been released with this synth driving it. I think the audio comparisons between the Genesis and SNES would have been...a bit more balanced and less critical of the Genesis all the time in reviews BITD.

Take a listen for yourself and see:

Theme from Toejam and Earl 2 on the Genesis through the 3438 synth:

Here is a song that sounds better than it did originally but the main bass note is a different instrument so it sounds perhaps a bit off: Also from Toejam and Earl 2 on the Genesis through the 3438.

And then you have a great example of how much clearer the drums and stereo separation is with this wonderous Synth. This is from the unreleased game ResQ - Level 5 music composed by the great Matt Furniss. (I think he knew how to make a Genesis play FM music better than anyone!)

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