Famicom AV Modification / Mod

[JC]

and how i can use the famicom on pal television? on my i'll see it in black and white 

I think the only solution to that is buying an NTSC TV or buying a PAL Famicom from Hong Kong/Taiwan. I forget if Famicoms from there are PAL.

[133MHz]

Or getting a transcoder (little box which translates NTSC video to PAL).

[JC]

Ooooo. Wow. I hadn't heard of one of those. I guess I should have suspected it...where there's a need, there's a company willing to provide for it.

[133MHz]

Those are pretty common in South American countries where the TV system used is PAL but video game consoles are NTSC (or when NTSC games are preferred over PAL). Argentina is a good example, they use PAL-N which is not color-compatible with the more common PAL-B in which video game consoles come, so people used transcoders, hacked their consoles to output PAL-N or technicians installed boards inside their TV sets to do the conversion internally, but today most TVs are multisystem. Chile on the other hand is NTSC-M like the US

[NHJ]

I did some investigation onthe AV mod on the site.

it has false things, the biggest mistake if on the video circuit.

you should solder a 5v with the resistor to the RCA output

so i started to wonder the purpose of this until i took my multimeter, the point labeled 5v on the mod is in fact a ground, if you have a look at your board you may guess that without tool.

the ground point on the board like the reset switch ground we use have a CLEAR green as the "5V" point has and all DARK green do carry power.

i finally suceeded to have an output image but it's a so bad quality , i think there's something wrong with the mod on the page, i checked with my multimeter and i don't even have 5V something like 3.7v with or without the link to resistor to ground.

also when the mod is in place the RF unit outputs a so bad signal certainly because of the shortcut on IN1 and IN2 .

could someone or the webmaster give me the original page even in japanese, i can read it if katakana and hiragana are used or even ask for a translation.

thank you

[NHJ]

I've been able to find back the original link : http://web.archive.org/web/20060507223007/http://www.chuma55.net/game/special/famicom/contents/famicom2.html

however images are missing, notice the part list is very different from this site.

[Arnold101]

Or getting a transcoder (little box which translates NTSC video to PAL).

oh thanks, do you know one cheap?
i have find this (description says pal ntsc signal supported)
http://www.ebest24.com/product_info.php?cPath=30_241&products_id=1675&language=en 
http://cgi.ebay.it/TV-media-Tuner-Ricevitore-Box-per-LCD-CRT-TFT-Monitor_W0QQitemZ290179244543QQihZ019QQcategoryZ138341QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

are the same. it have composite video input and ouput.
it is ok for my use?

and for audio?

now audio work  but the volume is low (tv volume at max). is normal? what can i use for make it higher?

thanks

[133MHz]

No, that's not a transcoder, that's a scan converter to watch TV on your computer monitor. As you say it supports PAL but it won't allow you to watch PAL in your TV, just your PC monitor. I don't know where to get one cheap since I never had the need for one (my country is NTSC-M). Check eBay or electronics stores around you.

As for the low audio, you can build a small amplifier inside the Famicom to boost it a little. A small audio amplifier IC like the LM386 is perfect, between the Famicom's audio output and the audio RCA jack. For power just tap the unregulated supply and you're good to go .

[133MHz]

Small, cheap and simple audio amp based on the extremely common and cheap LM386 IC:



As I said put it between the AV mod's audio out and the RCA jack, for power you can tap the unregulated supply since the chip won't care and that way you won't load down the +5V line.

As for the 10k pot you can use a small 'trimmer' one so it will fit inside your Famicom and you'll only need to adjust it once. Set your TV to a comfortable volume level (the one you use most) and turn the pot until it sounds at a good volume and no audible distortion is heard.

[Arnold101]

No, that's not a transcoder, that's a scan converter to watch TV on your computer monitor. As you say it supports PAL but it won't allow you to watch PAL in your TV, just your PC monitor. I don't know where to get one cheap since I never had the need for one (my country is NTSC-M). Check eBay or electronics stores around you.

As for the low audio, you can build a small amplifier inside the Famicom to boost it a little. A small audio amplifier IC like the LM386 is perfect, between the Famicom's audio output and the audio RCA jack. For power just tap the unregulated supply and you're good to go .

thanks mate 

the one that i inked have the composite video out for tv, see it here


and it support ntsc-pal so i think is good. or not? (can you link me your type of transcoder?)




for audio: so is normal the low audio in famicom av mod or affect only me? and what is the function of the 1uf capacitor for the audio?


thanks for info for the LM386, i have some question on it

1- at Vin goes famicom audio, and to Vs ?
2- the trimmer you say goes on Vin side right? i see it here http://www.talkingelectronics.com/projects/MiniBenchAmp/MiniBenchAmp.html
this volume trimmer, but what is the component name? i can't find
3- for power i have not understand very well, it can be linked to 5v of the famicom or not?
4-gain 20 is good for my very low volume?
on the circuit i see various resistors simbol, one with number and k and other without the k. example 10k and 10. why?

big thanks for the help

[133MHz]

the one that i inked have the composite video out for tv, see it here
and it support ntsc-pal so i think is good. or not? (can you link me your type of transcoder?)

Yeah but the composite out is just a pass-through, the signal will pass as-is as if the box weren't connected.

Here's one of the transcoders I'm talking about.

for audio: so is normal the low audio in famicom av mod or affect only me? and what is the function of the 1uf capacitor for the audio?

I don't have a Famicom, so I can't tell. Maybe your TV is a little finicky about the signals it receives, and a little boost may be all that's needed. The capacitor blocks any DC going to the speaker. (speakers don't like DC, it produces no sound at all, makes the voice coil hot and could burn it).

thanks for info for the LM386, i have some question on it

1- at Vin goes famicom audio, and to Vs ?
2- the trimmer you say goes on Vin side right? i see it here http://www.talkingelectronics.com/projects/MiniBenchAmp/MiniBenchAmp.html
this volume trimmer, but what is the component name? i can't find
3- for power i have not understand very well, it can be linked to 5v of the famicom or not?
4-gain 20 is good for my very low volume?
on the circuit i see various resistors simbol, one with number and k and other without the k. example 10k and 10. why?

big thanks for the help

1) Vs is the LM386's supply voltage. You can connect it to the +5V or to the unregulated supply line. Just connect it after the power switch so the thing does not stay on all the time .
2) Yes, the 10k trimmer goes in there. I think it's called trimmer potentiometer.
3) Yes you can. I recommend tapping the unregulated ~10V though, but it will work both ways.
4) Yeah, you don't need a lot of gain, just a little boost (remember the TV has an amplifier inside, you don't want to overload it, because it'll sound horrible).

10k is 10 kilo ohms or 10.000 ohms, 10 is 10 ohms. Simple

[Arnold101]

thanks, perfect as ever 

for gain, i want to use it even on the dolby digital 5.1 home theater (that now at max volume is low like television)

so it's ok the connect it at 5v of the av mod? because you talked of the 10v (and where it is?)


Thanks for the transcoder link    i want that model, but the shop don't have anymore
do you know another european shop that have it?    thanks

[133MHz]

thanks, perfect as ever 

for gain, i want to use it even on the dolby digital 5.1 home theater (that now at max volume is low like television)

If it works well on your TV, it will work well on your home theater system too.

so it's ok the connect it at 5v of the av mod? because you talked of the 10v (and where it is?)

You can tap the unregulated supply at the left pin of the 7805 voltage regulator on the RF board. The middle one is ground and the right one is the regulated +5V supply for the CPU. You can experiment with each one to see which one gives the best results.

Thanks for the transcoder link    i want that model, but the shop don't have anymore
do you know another european shop that have it?    thanks

Unfortunately I don't know another place to get it. Maybe someone here who lives in Europe might know .

[Arnold101]

play asia have the transcoder 

thanks for 7805 info   

[133MHz]

Here's the transcoder Arnold101 found on Play-Asia.com .

Maybe this could be stickied somewhere on the site to help our members trying to play their NTSC Famis on PAL TVs