Video amp

Kai · Post by **Kai** » Sun Jul 24, 2005 7:02 am

Hi
I've got a question how well does the amp work?
has any one pics? is it as good as the original rf-modul?
I build one my self but the quality is not that good but perhaps i have to vary the resistor values cause its pal (wich resistors should i change???)

THX

Kai

bioniclebert · Post by **bioniclebert** » Sun Jul 24, 2005 6:00 pm

http://www.classicgaming.com/nestable/i ... lifier.gif

there is a schematic of that guys that worked.

http://www.classicgaming.com/nestable/schematics.shtml
This is the page w/ that pic.

I was wondering what the purpose of a NES video amp Is?

nos_slived · Post by **nos_slived** » Mon Jul 25, 2005 12:33 am

Most people find the video signal from an NES very weak, especially after removing the RF box, or if they use a NOAC. The video amp is used to strengthen the signal, and get a better picture.

Kai · Post by **Kai** » Mon Jul 25, 2005 8:12 am

i'll try that one
another question there was this french guy who build a nesp he must have used a european model i think. has anyone the link?

EDIT:
Forget about the link the amp you posted works perfect looks just like original rf modul perhaps a little bit brighter but no glitches no lines... perfect
it works better on Pal than the original from the book if any one knows how to add a bright controll please post
Thanks a lot !!!

EDIT:
Forget what I said the one in the book works just the same i must have soldered the first one wrong
but it also works if you only use the 33 ohm resistor and leave the 220 ohm's away
(what are they for??)

G-force · Post by **G-force** » Thu Jul 28, 2005 9:39 pm

I tried that amp yesterday and it didnt work. All I got was complete black video.

*o* · Post by ***o*** » Fri Jul 29, 2005 6:40 am

was it the video or the source that wasnt working?

codeman · Post by **codeman** » Tue Aug 16, 2005 10:39 am

Hey, i'm a little late in replying, but i just now bothered to register. The video amp can also be done using the 2N3904 NPN transistor that every radio shack carries. Just replace the 33ohm resistor with a 10ohm.
The circuit is a current amplifier rather than voltage, so reducing the 33 ohm resistor compensates for the lower gain of the 3904. If you want it brighter, just lower the resistance.
I tried this with the old NES with the RF unit removed and it worked great. As for the black video, make sure you have ground connected correctly too, that was my problem at first.
hope that helps!

usbcd36 · Post by **usbcd36** » Tue Aug 16, 2005 12:27 pm

If you need more flexibility, try tuning a couple pots to the values of the resistors and building the circuit. Then if you don't like it, just adjust the pots.