NES Stereo Mod

[SukkoPera]

This is my first post here, so hello everyone .

I am going to NESRGB-mod my NES. I was thinking about doing the "real" stereo mod as well, but I have a few doubts.

One thing that is for certain is that I want it to be "tweakable", I don't want permanent separation. Now, most schematics I can find (http://www.retrofixes.com/2013/09/nes-s ... -easy.html, for instance) seem to use two separate pots to mix some mono signal into each channel separately. A video from Game-Tech I saw on YouTube uses a single pot to "regulately" bridge the two channels together, so that with the pot at 0 you get mono and at full scale you have total separation.

I am wondering that the best approach is, from an electrical point of view. I was trained a bit in electronics, I am no expert, but as I guess the CPU output channels weren't designed to be connected this way (and not even to be connected straight to outputs) I am afraid they don't have the right impedance, so current can flow back into the CPU and damage it. The guy I got the NESRGB kit from confirmed he fried a CPU while experimenting with sound.

The capacitors that most schematics use will only stop DC. Introducing diodes would distort the sound, I guess, so it's no viable solution. So what should I do? Did someone design a proper opamp-based circuit that can sum the CPU outputs without any issues?

[korpse413]

Sorry for the super necro here but I wanted to search the forums before starting a thread on this topic. Anyone with this mod can confirm that it is worth it? I am considering this mod myself, true stereo over the dual mono (which doesn't exactly seem necessary, all you need to buy is an rca splitter for pennies). Looking for the couple guys to say with such enthusiasm of, yes dude, get the mod, or else I might just stay pure with the mono sounds. Thanks.

[bobrocks95]

You can find videos on YouTube and listen for yourself to see if you like it. Personally I don't like how it sounds, at least with headphones- haven't listened to how one sounds on an actual TV or anything. It's very artificial sounding from the separation.

There's of course different levels of partial separation, and I know a lot of people like the sound of something along the lines of 25-50% separation so you still hear each wave signal/instrument in each channel, they're just stronger in one of them. I don't have much experience with this, but I think most youtube videos of ripped NES OSTs do this.

The purpose of stereo is to make the sound fuller, which I think (YMMV) dual mono does just as well, and to add directional audio with panning, which separating certain sounds with the NES mod can't do. It's all down to personal taste really, but I'd say since the games weren't designed with stereo in mind it's not worth it.

[Glossectomy]

The mod sounds like shit in my opinion.

[BazookaBen]

NES never had stereo, so the developers always designed sound for mono. Given that, why would you want stereo?

[SukkoPera]

Well, the point in my original post was to have a well-done tweakable mod, so that you would be able to get the original output or try to add the desired amount of separation on a per-game basis. That wouldn't hurt anybody's feelings.

I wish we could have a "how to do it" thread rather than a "don't do it, it sounds like sh*t" thread, but it seems every thread I open on every forum ends up like that.

Anyway, it seems that oldskoolconsoles had a new sound mod that... sounds interesting, but there are no schematics as far as I can say, you can only send your console in to be modded.

[hosser]

Well, the point in my original post was to have a well-done tweakable mod, so that you would be able to get the original output or try to add the desired amount of separation on a per-game basis. That wouldn't hurt anybody's feelings.

I wish we could have a "how to do it" thread rather than a "don't do it, it sounds like sh*t" thread, but it seems every thread I open on every forum ends up like that.

Anyway, it seems that oldskoolconsoles had a new sound mod that... sounds interesting, but there are no schematics as far as I can say, you can only send your console in to be modded.

My Famicom was modded by Dave from oldskoolconsoles. The photos on his site are of my console - he mounted a little knob on the side of the case that mixes the audio. It sounds way better in "stereo" IMO.

[SukkoPera]

Well, what I would like to see are the internal connections . When did he do this mod? The one he's offering right now is pretty new, he has spent some time developing it, so if you got yours more than a couple of months ago it is probably one of the "traditional" mods I talk about in the OP.

[hosser]

Well, what I would like to see are the internal connections . When did he do this mod? The one he's offering right now is pretty new, he has spent some time developing it, so if you got yours more than a couple of months ago it is probably one of the "traditional" mods I talk about in the OP.

Mine was the first one he did Done in late May. This is the only photo I took of the interior.

[Skips]

Well, what I would like to see are the internal connections . When did he do this mod? The one he's offering right now is pretty new, he has spent some time developing it, so if you got yours more than a couple of months ago it is probably one of the "traditional" mods I talk about in the OP.

Mine was the first one he did Done in late May. This is the only photo I took of the interior.

Why did he use an NESRGB and put that huge ass mixing pot on it. The NESRGB Famicom PA board comes with a tiny trimming pot that goes on the bottom so you don't have it sticking out the side like an eyesore. When having the audio channels separated (as in not in full on mono) I found I rarely had to actually adjust it when playing various games. It was one of those things you set to your liking and just forget about. That audio mod is not really one he did, that is just the built in audio circuit on the Famicom PA board. It is the basic way you connect audio when using the Famicom NESRGB kit's power board. The only thing he did differently was put that huge ugly potentiometer on it instead of using the seamless option provided with the kit.

P.S. Do people not realize you can buy panel mounted 8 pin din ports that secure to a shell via a nut? I really don't see the point in half ass glued ports like this when those cost at most $2 a piece.

**edit**

This is what the option that comes with the NESRGB Famicom kit looks like. Much better and cleaner looking.

[korpse413]

Sukko I was in the same boat as you after watching that GameTechUS vid with the potentiometer controlling between stereo and mono, just so I could use it as a novelty and surprise friends or something. I remember watching a Castlevania 3 stereo sample and it sounding great.

[SukkoPera]

That audio mod is not really one he did, that is just the built in audio circuit on the Famicom PA board. It is the basic way you connect audio when using the Famicom NESRGB kit's power boar

Right, but I would just like to do the same thing on a Front Loader NES.

[noonan2678]

I have the single POTS (knob) option on my front-loader. I had it modded custom along with RGB and a couple of other tweaks. I have a larger knob that can "mix" between dual mono and "stereo." Also, the extra channels for Famicom are enabled.

Pros: The stereo mod sounds really great on most games. I don't have control over which sounds go to which channel, but I haven't found a game where I wasn't pleased. This mod allows for a very fine range of mixing between dual mono and stereo. I find that about 90% of the way to stereo on the knob is a nice mix for me.

Cons: Because of the way dual-mono is grabbed with this mod, it's very bassey and a bit muddled. So, the full-on dual mono is not as good as it would be if it were wired on it's own. Also, there is a ton going on inside the console and using the NESRGB chip, so I have a very faint interference coming through the audio. I thought it was originally not grounded properly, but it is and it seems like something that may not be able to be avoided. It's very minor and unnoticeable when any sound is coming through.

Overall, I would do this option again if I had the choice. I like the flexibility and really like how the stereo performs on nearly all of the games I've tried.