Everyone seems to have problems with the sound of the NES side of the Retroduo. I think I found a fix for this.

http://www.digitpress.com/forum/showthr ... ?p=1566335

Also I found another hack to add a 50/60 Hz switch to the SNES side, and 5 replies down, a commentor suggests how to fix the video of the SNES side.

http://www.gatchan.net/index.php?archiv ... erendipity[lang_selected]=en

Not sure if these have been discovered before but I'd thought I'd share.

There's actually more to the sound fix than just that capacitor. I found out, while looking at my FC Twin's NES sound circuit, that there's not only a capacitor missing on the RetroDuo's NES sound circuit, but there's also a RESISTOR missing from the circuit, and if it's not present, the sound will be okay, but very rough.

The resistor in question is 2.2Kohms. It need to be soldered on a transistor on the RetroDuo's NES board(I don't remember which one it was, and I don't have my RetroDuo with me to check)

I tried that video fix for cleaner Super NES Composite and S-Video, but it didn't work. Instead of cutting the trace, I actually lifted the pins of the KA2198BD off the board and soldered the Composite and S-Video outputs from the KA2198BD to the Composite and S-Video jacks, and while the colors appeared better, the video itself STILL had those stubborn strips of static. Although I didn't use any capacitors, so I will give the Super NES video fix another shot(I will be using higher-value capacitors as the KA2198BD's datasheet says, which is 470uF).

I'm just curious: has anyone replaced the KA2198BD in their RetroDuo by the Sony CXA1645(they should be pin-for-pin compatible)? If so, was there any improvement in the video quality?

EDIT: The 2.2Kohm resistor goes between the top pin and the bottom-left pin of transistor Q8 on the NES board. Apply that resistor and the 0.1uF capacitor(electrolytic or ceramic, it doesn't matter), and you will get the best NES audio possible out of the RetroDuo.

Thanks for the clear-up Ace.

Tried the video fix for the Super NES side with a 470uF capacitor. The static is STILL visible, but it's almost cleared up completely(it's very faint, now; before the video fix, the static was clearly visible on EVERY game I played). A word of note: if you're using the standard RetroDuo video amp for the NES side when performing the Super NES Composite video fix, the Super NES Composite will be darker than it should, but you can do this to improve the Super NES video and make the NES video a little more saturated so that the colors come out better:

-Cut the part of the NOAC ribbon cable that carries the NES video
-Cut the part of the shared ribbon cable that carries all video signals(Composite, Chroma/Luminance)
-Solder 2 75ohm resistors in series(or a single 150ohm resistor) from the NOAC Composite output on the NOAC board to the Composite plug

This will darken the NES Composite a little bit and make the colors a little more saturated so that the video matches that of a Front-Loader NES a little more, and, in turn, will brighten the Super NES Composite. With this, however, you will lose NES S-Video, which begs the question: how is the S-Video even made possible on the NES side? I know it's the Composite signal being run through the S-Video jack, but how does one output Composite into an S-Video jack?

I have a spare PSX model 5501 that has the Sony CXA1645M in it and a Retro Duo I don't mind experimenting with. Do you have any tips on desoldering the chip from the PSX board?

http://i55.photobucket.com/albums/g157/ ... 1e5e60.jpg

This is probably a redundant question but, after the nes side is taken off, so you have straight video signals, there is no more crappy video right? (for the portable of course)

I haven't tried, but I think this supposed "ground loop" is on the Super NES board(what exactly is a ground loop and how do you eliminate it?). I once tried to hook up the Super NES Composite and S-Video straight into the RetroDuo's Composite and S-Video jacks, but it did absolutely nothing to eliminate the static. But from what I heard, not all RetroDuos are made equally, and the hardware varies between paint jobs. Some RetroDuos supposedly have no such issue with static on the Super NES side's video output, and I remember one of the older RetroDuos(those that come in this box: http://www.itechnews.net/wp-content/upl ... ulator.jpg) having no such problem with static on the Super NES side's Composite video. The new ones(with this boxart, which is the RetroDuo I have: http://imgs.inkfrog.com/pix/gamedepot/r ... hite_2.jpg) also have bad video off the NES side unless you add the resistor and capacitor to the NES side's audio circuitry. The video itself is sharp(although a little washed out), but without those parts, you will get diagonal strips on the screen that scroll from left to right on top of waves that are in sync with whatever sound is being output from the system.

A word of note(and probably unrelated): I don't plan to make a portable out of my RetroDuo. If anything, I'd use my FC Twin because I can't fix that damn thing's NES sound circuit(every time I do, it works for about 2 minutes before the sound wants to cut out completely; I get nasty popping noises and A LOT of hissing), but the Super NES board still works perfectly.



Desoldering surface-mounted components is one thing I absolutely HATE to do. Every time I use my soldering iron to desolder a surface-mounted chip, not only does the chip come off the board, but so do the traces that the chip was on. Instead, I just stick an X-acto knife behind the pins on said chip and push outwards. The pins will break off the solder without breaking the traces. Just don't apply too much pressure because then, you might be able to break the traces too.

Report back when you're done about whether the static is eliminated or not. I know Samsung made some really nasty encoders(the KA2195D comes to mind; was used in the Genesis Model 2 and resulted in the worst Composite video I have ever seen. THE ENCODER DOESN'T EVEN OUTPUT S-VIDEO!), so I'm wondering if the static is actually caused by the encoder and not the circuitry around it(I know the CXA1645(used in the Yobo-branded FC Twins, late Genesis Model 2s and the Genesis Model 3) outputs VERY SHARP Composite and S-Video, so if there's still static in the video, we can confirm that the circuitry on the RetroDuo is causing some sort of interference).

OK I spend the morning installing the Sony CXA1645M in the RetroDuo. However I'm getting no video on the SNES side with composite or S-Video. The NES side works fine. If I turn up the brightness on my TV with S-Video I get scrolling white bands, the audio works fine. What a piece of crap.

http://i55.photobucket.com/albums/g157/ ... 763f19.jpg

I just took a look at the CXA1645 and KA2198BD datasheet and I noticed that the CXA1645 requires a few more components to work properly. Compare the datasheets:

-CXA1645(look on page 10 for the NTSC circuit): http://www.gamesx.com/rgbadd/cxa1645.pdf
-KA2198BD(circuit on page 6): http://www.datasheetcatalog.org/datashe ... Xvvrux.pdf

There appears to be a regulator of sorts on the CXA1645 that's absent on the KA2198BD. You may want to add those components, which are the following:

-A 10uF electrolytic capacitor on pin 14(you can use solder spot CE25 right next to the encoder).
-A 47Kohm resistor in parallel with a 0.1uF electrolytic capacitor to ground. This goes to pin 13. There's no solder spot for this stuff since pin 13 is a No-Connect(NC) on the KA2198BD, so you may need to make the circuit on a small breadboard.

sorry for the random bump.

after my long absence, i was finally able last night to go through and update the main page. i believe i got it all...

keep the compatibilities coming!

Huh, mine didn't have that capacitor attached to the power switch... But I don't have the game to test the compatibility either...

Hey everyone,

So I've got some question about the retro duo. I just bought one and at the moment I'm not so happy with it. It doesn't play any of my NES games and I only have 2 SNES games which are Super Mario Kart and Super Metroid (Super Metroid gives me a message saying something about that i cant play it on a super famicon or super NES). So my questions are:
Is it possible to take the 72-pin connector out of the retro duo and put it in my old NES?
And is it possible to do some kind of trick to get Super Metroid working on the retro duo?

Also the person where I bought it from said I can only play NES games on a NTSC tv is this true or just rubbish?

Thanks in advance
-Yordi

are your games pal or ntsc? i'm assuming from the message you get for super metroid that they are pal games? the retro duo isn't known for great pal compatibility. did you have a look over the list in the first post? pal nes and pal snes are listed separately in their own categories.

there is a mod linked to do the 50/60 mhz. but the duo will only display in b&w if i recall correctly.

edit - i just realized i didn't address your actual questions. do you have the old toaster? if so, it is possible to use the 72 pin connector, but it requires a lot of modding of the nes.

you can probably get super metroid to work with the proper adapter. this is what i have about the pal game terranigma: "does not work. this upset me. if my understanding is correct, this game has the strongest form of lock out available. however, it does work when using the pro action replay mk 2.t." the pro action replay mk 2.t & mk 3 are the best for compatibility. you will need a good ntsc game to use for the key tho. super mario world works well for the key for terranigma.

and i'm not sure about the tv issue. i'm fairly certain people use them on pal tvs.

Well first my games are both PAL games, and yes i looked over the list but i already bought the game so though luck for me.

I have the regular PAL NES so not the toaster.But does that mean it is not possible because the retro duo and my PAL NES have different 72-pin connectors? And I'm still new to this whole modding stuff so if you can give me a link explaining how I have to do the pro action replay mod I would appreciate it very much.

-Yordi

ok, now i'm just confused. what do you mean you have the regular pal nes? the regular pal nes is the same in appearance as the us nes.



there is the nes2, is that what you mean you have?



a 72 pin connector is a 72 pin connector. it doesn't matter if it's from a pal or ntsc machine.

the original nes's cart slot looks like this:



the nes2's and all the clone nes systems have a normal 72 pin connector like this:



as you can see, they are drastically different. to get a normal 72 pin connector to work in the original nes, it requires a lot of modding of the inside of the system.

and the pro action replay isn't a mod. it's an adapter you buy. here is a silly pic i took of it in my handyduo - obviously not practical to use in a portable:



the adapter goes in like a normal game. then the pal game goes on top of it. then, on the back, is where you put the "key" game. so it's like 3 game carts together.