Famicom | AV Mod

Has everyone been using the famicom world guide?

I don't want to rock the boat here but I have reservations about a lot of the info thats in that guide, especially if you take a look at the forums. For a start, lot of useless components had to be taken out oh the first schematic after kyuusaku posted the nintendo schematic, then somebody decided to change that when it probably didn't need to be. I really don't trust that site for this mod.

I only seem to get "jailbars" when playing SMB, though my capture device, but on the recordings its not really that noticeable, which leads me to think that its maybe more to do with the monitor? I seem to remember somebody suggesting that the type of monitor that you're using can be effected by what resistors you have in place , is the nintendo guide posted by kyuusaku intended for a CRT monitor? Most people seem to be using LCD, some older consoles do struggle with HD tvs... Has anyone tried using a different value of resistor?

 

Well I do know when using a flat screen tv the jail bars will be more noticeable.

 

I've tried 80sfreak amp on a crt & lcd and it looks bad on both. Yeah the guys over at famicom are a bit clueless.
Going to try kyuusaku amp next but I'm in no rush to buy the caps as I dont think any amp will get rid of the jail bars.

 

Were you using the 33uf cap? The kyuusaku guide gave the best results for me, except I'm using two 330 ohm resistors (10% tolerance) while I'm waiting for extra components to arrive.

I had a quick look at the thread regarding the RGB mod and jailbars do appear there as well, there is a fix however but I'm not sure whether it would effect anything here..

It could be nothing to do with the amp but I don't think that wrapping the PPU in copper is the answer either?

 

Hey just wanted to thank y'all on this thread, got my famicom this morning in the post and thanks to the information here I had it AV modded within 2 hours
For me the jailbars are only noticeable on games with solid coloured backgrounds, most prominently on blacks and blues and even then they're pretty faint.
I used the Nintendo schematic, lifted pin 21 but used 100 and 330 ohm resistors rather than 110 and 300.
Not that I'm too fussed about it but I'll be keeping an eye out just in case any of you come up with a fix.

But anyway just to say thank you for helping me cut through the 3 million or so guides to find something simple yet functional

 

Glad to hear that you got it working : ) The kyuusaku schematic works really well, I only seem to get faint jail bars on some of those backgrounds too. Apart from that I think that the image is pretty good for a composite signal.

 

Yeah definitely, truth be told it looks better than the composite signal from my NES, in fact the whole system looks nicer, smaller than I expected it to be though haha

 

I've yet to try it on a flat screen, I will try over the weekend and then put my famicom back together. : )

 

It's Nintendo's choice of components so it should work! The only difference is that I took out the series ferrite bead and parallel small capacitor on the output which both have low pass filtering action. Filtering may help jailbars but it just hides them under the rug.

The only way to improve on Nintendo's (cheap) circuit is to add more transistors. Even so a better output circuit will not get rid of jailbars.

 

Heh, turned the brightness down on my TV and just like that the jailbars are almost nonexiastant!
That's good enough for me
Not going to be de-soldering that whole chip just to put a bit of copper around it on the off chance that it might fix everything, this machine is several years older than I am, I'm not expecting HD output.

 

Same here the jailbars are not that bad for me and I feel that de-soldering the PPU is a rather drastic measure, if you're going to do that then you might as well go for the RGB mod. It's only a composite signal so there's only so much that you can do really, it's still much better than RF so I'm quite happy with it.

Thanks for all the info, it's very much appreciated : )

 

Well being in the UK, I didn't even know whether or not the famicom worked before I did the AV mod, so it's pretty safe to say that for me the AV mod looks a lot better than the picture I had before (as there was none at all) :highly_amused:

 

Either you made mistakes or you can't really mod something.
A friend and I got 2 composite modded famicoms from 80sFreak directly. We play on different sets and I have tested my machine on at least 3 lcd and 4 crt tvs. Not only does the machine's composite works perfectly , there are also NO jailbars.

So yeah.... here are some shots from a mod that a "clueless" person did:

CRT (some shots have 100% brightness)








LCD (no filters, no enhancements, game mode with all processing that a user can set to OFF)

 

Interesting, I wasn't aware that there was actually a jailbar free solution, would you mind posting some pics for comparison purposes?

 

Matisfaction , I edited the post above.
Not trying to offend anyone but claiming that something does not work because you can't get it working for some reason is just wrong.

edit: does photobucket now resizes uploaded pics? wtf? here is a .zip with the untouched pics: http://www.mediafire.com/?8ezp8r3zsr669cn

 

Thanks for sharing the pics, I'm not claiming that it doesn't work, I just think that the threads on famicom world are really confusing and that there's a lot of misleading info on there...

 

Well, if one is satisfied with turning down brightness to avoid jailbars then I can't argue with it. To each their own.
My main gripe here is the constant badmouthing that is happening here for all the wrong reasons.

 

I don't know about any brightness issue, and I don't believe that I've bad mouthed anyone either?

Once again thanks everyone for all the info etc, it's been very helpful.

 

Hmm that's funny coming from someone who couldn't be bothered to even attempt the mod and just resorted to buying one already modded. The cheek of you!
Why not post some pictures of the board so we can all feast on the great work of this so called genius. Since we have no idea what he's done to your famicom you really cant compare to what I've done to my famicom, can we now?
The fact is the video amp of his will not remove the jail bars on its own. Will any of his other recommendations do the trick? I don't know because I haven't done them yet.

 

Most likely keropi fami has the ppu shielded with copper tape then grounded to pin 20 on the ppu.