N64 RGB Amplifier (IC Based)

Started by Piratero, May 30, 2010, 07:13:21 PM

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Piratero

Hello everyone!

I'm back and excited to try out the new RGB amp. But before I begin, I have some issues that I would like to iron out first.

The diagram below looks pretty much identical to the wiki, but there are some changes here and there.

1. Does this diagram look OK?



Thanks!


Piratero

Sorry for so many updates. I changed to gEDA (which is simply amazing).

kendrick

I like the revised diagram more than your original post. Labeling each of the pins is a good idea and removes ambiguity about whether or not each connection is what you think it is.

The original wiki schematic appears to show that each chip gets its own set of capacitors for the power input, whereas your revised diagram has only the one set of caps. Are you comfortable with that? It seems like to me that the original diagram made those separate deliberately, and counting the components on the perfboard in the wiki picture seems to indicate that each chip gets its own. I'm not sure what the effect of sharing those components would be.

Piratero

#3
Quote from: kendrick on May 30, 2010, 09:50:27 PM
I like the revised diagram more than your original post. Labeling each of the pins is a good idea and removes ambiguity about whether or not each connection is what you think it is.

The original wiki schematic appears to show that each chip gets its own set of capacitors for the power input, whereas your revised diagram has only the one set of caps. Are you comfortable with that? It seems like to me that the original diagram made those separate deliberately, and counting the components on the perfboard in the wiki picture seems to indicate that each chip gets its own. I'm not sure what the effect of sharing those components would be.

Hi kendrick, thanks for the reply.

Yes, I saw that the wiki's schematic has its own set of capacitors. But if U2 has its own set of capacitors on the V+ line, I still need to somehow obtain 5.0V from the same place.

Though, I don't think it's a problem, but is it safe just to have a common ground?

A bit off topic, but what software is used to create a diagram like this?

kendrick

Ground is common by default. Even with RGB, my position is that isolated ground is only necessary for the shielding along the external wiring, and even then it's common again once you get to the video device. I'm pretty sure common ground inside the amp is just fine, and since you don't have split voltage happening you shouldn't have to worry about the two ICs sharing it.

Piratero

Quote from: kendrick on May 31, 2010, 08:18:22 AM
Ground is common by default. Even with RGB, my position is that isolated ground is only necessary for the shielding along the external wiring, and even then it's common again once you get to the video device. I'm pretty sure common ground inside the amp is just fine, and since you don't have split voltage happening you shouldn't have to worry about the two ICs sharing it.

Thanks for clearing that up! I'll start cutting the traces tonight!

Piratero

It seems like I have a grounding issue. Everything is grounded. What could be another reason why I still have heavy interference? Though, the colors still look a bit dark.

I really hope no capacitors are destroyed, especially the IC's.

kendrick

The components are probably fine. What have you housed your amplifier circuit board in, and where are you drawing your power from? External interference and a dirty power signal would be the first two things I would look at. You might need some bigger capacitors on the five volt input to smooth it out some, and a giant aluminum box to put everything in might not hurt.

Piratero

#8
Quote from: kendrick on May 31, 2010, 11:10:46 PM
The components are probably fine. What have you housed your amplifier circuit board in, and where are you drawing your power from? External interference and a dirty power signal would be the first two things I would look at. You might need some bigger capacitors on the five volt input to smooth it out some, and a giant aluminum box to put everything in might not hurt.

I'm drawing power from the bottom of the N64.

I haven't housed it in anything yet as it still doesn't work, but I just protect it with using an anti-static bag.

External interference... that's what I thought, but my other N64 which has viletim's mod works fine and so do other consoles.

How can I check if I've blown a capacitor? Should I just use a voltmeter?

Piratero

#9
Damn, I think I might have to start over. Those video amplifier IC's are expensive :'(

Well, I tried rewiring this on a bread board and I still get a washed out image along with extremely high hue on all colors. I think I fried the video amplifier because while soldering, I felt the IC to be extremely hot.

Anyways, time to save up money, buy a new soldering iron and try again! :o

RGB32E

#10
Quote from: Piratero on June 01, 2010, 10:23:59 AM
Damn, I think I might have to start over. Those video amplifier IC's are expensive :'(

Well, I tried rewiring this on a bread board and I still get a washed out image along with extremely high hue on all colors. I think I fried the video amplifier because while soldering, I felt the IC to be extremely hot.

Anyways, time to save up money, buy a new soldering iron and try again! :o

Guess I'm late to the party... ;)  I'm the author of that wiki entry.  

I think you had a number of capactiors with incorrect polarity... all 3 electrolytic caps should be pointing away from the NJM2267 as seen from my attachment.  The negative side '-' side should be pointing away from the chip, and the postive ends should be connected to the chip.  

The eletrolytic decoupling cap (power) should have negative to ground, positive to +5VDC.  Also, I use a twisted pair of conductors for power.  The thought being that one conductor carries +5VDC and the other is ground.  I first soldered the two wires to the circuit board.  Then with the two wires in parallel (physically) I soldered to the two respective connections on the SNES connector.  Then I turned the circuit board to twist the 5VDC and GND wires together for noise cancellation... in addition to the two decoupling capacitors on the video amp circuit.  So, the cleaner you can wire the better!

These pictures of my first build last year (currently using this particular build in a TG16 Turbo Booster):

4 Channel Amp with caps on 3 outputs for LPF



I can take pics from my actual RGB modded system if that helps. :D

If you want to purchase a pre-modded system, you could buy one here for $137 shipped (though I cannot confirm how the mod was done - NJM2267 likely). http://cgi.ebay.com/320505553353 ... or I could just sell you one myself! ;)

Piratero

#11
Quote from: RGB32E on June 02, 2010, 12:22:31 AM
Quote from: Piratero on June 01, 2010, 10:23:59 AM
Damn, I think I might have to start over. Those video amplifier IC's are expensive :'(

Well, I tried rewiring this on a bread board and I still get a washed out image along with extremely high hue on all colors. I think I fried the video amplifier because while soldering, I felt the IC to be extremely hot.

Anyways, time to save up money, buy a new soldering iron and try again! :o

Guess I'm late to the party... ;)  I'm the author of that wiki entry.  

I think you had a number of capactiors with incorrect polarity... all 3 electrolytic caps should be pointing away from the NJM2267 as seen from my attachment.  The negative side '-' side should be pointing away from the chip, and the postive ends should be connected to the chip.  

The eletrolytic decoupling cap (power) should have negative to ground, positive to +5VDC.  Also, I use a twisted pair of conductors for power.  The thought being that one conductor carries +5VDC and the other is ground.  I first soldered the two wires to the circuit board.  Then with the two wires in parallel (physically) I soldered to the two respective connections on the SNES connector.  Then I turned the circuit board to twist the 5VDC and GND wires together for noise cancellation... in addition to the two decoupling capacitors on the video amp circuit.  So, the cleaner you can wire the better!

Hi RGB32E!

No, it's not too late. I just need to get some more money to reorder the parts from Mouser. I actually didn't even use my own diagram, I used the one you supplied in the wiki and looking at the (dead) circuit I made, the polarity is in fact correct.

As for buying a modded N64, I already have viletim's mod (which I made last year around this time) on my other N64.

Just a couple of questions (if you don't mind):

1. What are those ceramic green capacitors for?
2. Are these the correct parts to order?

Thanks for the help!

RGB32E

Quote from: Piratero on June 02, 2010, 05:16:20 AM
Just a couple of questions (if you don't mind):

1. What are those ceramic green capacitors for?
2. Are these the correct parts to order?

Thanks for the help!

1. Used for a simple Low Pass Filter - an experiment for use with TG16/Duo, and NES RGB mods... not needed or recommended for the N64.

2. Yeah, all of those look correct.  It's just a matter of getting the right capacitor type (==), value (==), and voltage rating (>).  The items listed in your image all meet the requirements.  You could up the voltage rating on the electrolytic caps from 6.3V to 10V to play it safe.  If a part is dealing with 5V, a 10V cap will be more tolerant than 6.3V...  perhaps someone with more expertice could add more info.  ???  :P

Piratero

Quote from: RGB32E on June 03, 2010, 08:58:04 AM
Quote from: Piratero on June 02, 2010, 05:16:20 AM
Just a couple of questions (if you don't mind):

1. What are those ceramic green capacitors for?
2. Are these the correct parts to order?

Thanks for the help!

1. Used for a simple Low Pass Filter - an experiment for use with TG16/Duo, and NES RGB mods... not needed or recommended for the N64.

2. Yeah, all of those look correct.  It's just a matter of getting the right capacitor type (==), value (==), and voltage rating (>).  The items listed in your image all meet the requirements.  You could up the voltage rating on the electrolytic caps from 6.3V to 10V to play it safe.  If a part is dealing with 5V, a 10V cap will be more tolerant than 6.3V...  perhaps someone with more expertice could add more info.  ???  :P

Thanks for the info. I'll keep that in mind for when I buy the next batch. By the way, do you have any pics of the mod in action?

Also, have you done a comparison of viletim's mod?

Thanks!

RGB32E

#14
Quote from: Piratero on June 03, 2010, 09:08:31 AMThanks for the info. I'll keep that in mind for when I buy the next batch. By the way, do you have any pics of the mod in action?

Also, have you done a comparison of viletim's mod?

Thanks!

Sure, here's a pic and a video.  The output image on the N64 has always been too soft IMO due to the heavy use of filtering (texture op).  Please note, the vertical stripes in the picture are artifacts from taking pictures of an LCD.  I'll have to take a better one later (Mario's mug).



Zelda64 RGB

Note: No drop outs at the ~1:35 mark!  Time for celebration! ;)

I haven't tried Tim's mod, as I hate working with transistors (leg assignment ambiguity) and didn't want to remove any SMD components.

Piratero

Thanks! Looks great!

OK, yeah, the image my N64 outputs is very blurry even though it's in RGB. I just always used an emulator to verify and the image is much sharper on an emulator. I guess because it doesn't apply the filters.

Thanks for all your input.

RGB32E

Quote from: Piratero on June 07, 2010, 05:45:55 AM
Thanks! Looks great!

OK, yeah, the image my N64 outputs is very blurry even though it's in RGB. I just always used an emulator to verify and the image is much sharper on an emulator. I guess because it doesn't apply the filters.

Thanks for all your input.

Here's more.  I experimented with the Edge Enhancement setting and actually like the results!!!  Finally edge enhancement isn't a BAD thing! :D




Piratero


RGB32E

Quote from: Piratero on June 07, 2010, 06:29:58 AM
I don't see the difference. :)

Perhaps your visual acuity will improve over time... ;)  I spot the differences.

Take two....


Piratero


RGB32E


Piratero

What kind of LCD are you running the N64 on? This is very impressive!

RGB32E

Quote from: Piratero on June 07, 2010, 07:49:36 AM
What kind of LCD are you running the N64 on? This is very impressive!

http://gizmodo.com/5341202/non-review-i-love-you-sony-xbr8-triluminos-led-lcd-hdtv

I'm working on a brand new RGB amp for RGB mods... stay tuned, it should be good!!!   ETA for prototype update is 6/19/10

However, the NJM amp is a proven solution for N64 RGB mods.

Piratero

Quote from: RGB32E on June 09, 2010, 10:38:53 PM
Quote from: Piratero on June 07, 2010, 07:49:36 AM
What kind of LCD are you running the N64 on? This is very impressive!

http://gizmodo.com/5341202/non-review-i-love-you-sony-xbr8-triluminos-led-lcd-hdtv

I'm working on a brand new RGB amp for RGB mods... stay tuned, it should be good!!!   ETA for prototype update is 6/19/10

However, the NJM amp is a proven solution for N64 RGB mods.

Great! Keep us updated! But, why another? By the way, do you have screens of your PC Engine RGB mod? I have a Duo RX that is begging to be modded.

The only problem is that I need to send it to someone who is willing to cut a hole out for me. Someone who is very experienced. Heh.

RGB32E

Quote from: Piratero on June 10, 2010, 04:59:56 AMGreat! Keep us updated! But, why another?

Just because...  ;D  The new design has about half as many parts and higher quality (read overkill) and might give better performance for the noisy PCE and NES systems.  So, the motivation isn't really for N64 RGB mods, just the others.

Quote from: Piratero on June 10, 2010, 04:59:56 AMBy the way, do you have screens of your PC Engine RGB mod? I have a Duo RX that is begging to be modded.

No, I don't really have anything to post, but I can take some latter.  I have a NJM amp in my turbo booster and haven't replaced the old 2SC1815 based amp in my US Duo... waiting for my new design prototype to open that pit trap again! ;)  The Duo-R/RX are much easier to mod, as the Hu6260 chip is top side instead of the bottom (easier access).

Quote from: Piratero on June 10, 2010, 04:59:56 AMThe only problem is that I need to send it to someone who is willing to cut a hole out for me. Someone who is very experienced. Heh.

Ha!  You don't need to mount a new connector, just replace the 5 pin din with a 8 pin din, and replace composite video output with buffered composite sync.  Others have experienced compatibility problems when using composite video as sync... especially with the NEC systems.

Piratero

Quote from: RGB32E
Ha!  You don't need to mount a new connector, just replace the 5 pin din with a 8 pin din, and replace composite video output with buffered composite sync.  Others have experienced compatibility problems when using composite video as sync... especially with the NEC systems.

That's what I'm afraid of. I saw what it takes to remove the 5 pin DIN and I'd rather have a VGA out on the system...

Keep us all updated! Overkill is never a bad thing especially if you want to reduce the amount of parts!

Jibbajaba

I just finished installing this system in an N64, and the picture looks great!  I had never seen N64 in RGB before, and was told that it didn't have a very good picture, but this amp seems to have fixed that problem.

Thanks!

Chris

Piratero

Quote from: Jibbajaba on June 21, 2010, 08:41:34 AM
I just finished installing this system in an N64, and the picture looks great!  I had never seen N64 in RGB before, and was told that it didn't have a very good picture, but this amp seems to have fixed that problem.

Thanks!

Chris

Great work! By the way, which diagram did you use?

Jibbajaba

I used the diagram in the wiki (http://www.gamesx.com/wiki/doku.php?id=av:n64rgb-amp) because I had previously used it to build the same amp for my TurboGrafx, which I did before you created your diagram.  I already had the Wiki diagram printed out and sitting in a pile on my desk from the last time that I used it.

I'm going to build another one of these amps and stick it in my NES.  It has Moosman's amp in it now.  Maybe this amp will get rid of the faint jail bars.  Even if it doesn't, I did a pretty crappy job building that amp and should replace it regardless.

RGB modding is tedious and frustrating, but it's sooo worth it.

Chris

Piratero

Quote from: Jibbajaba on June 21, 2010, 04:55:06 PM
I used the diagram in the wiki (http://www.gamesx.com/wiki/doku.php?id=av:n64rgb-amp) because I had previously used it to build the same amp for my TurboGrafx, which I did before you created your diagram.  I already had the Wiki diagram printed out and sitting in a pile on my desk from the last time that I used it.

I'm going to build another one of these amps and stick it in my NES.  It has Moosman's amp in it now.  Maybe this amp will get rid of the faint jail bars.  Even if it doesn't, I did a pretty crappy job building that amp and should replace it regardless.

RGB modding is tedious and frustrating, but it's sooo worth it.

Chris

It sure is. My Dreamcast is next. Though, I have yet to see if the internal RGB/VGA mod is better than using a hacked up SCART RGB cable. Aside from the price, of course.

Jibbajaba

I just use a SCART cable.  Most of my RGB cables are SCART cables with the SCART end chopped off. Works great for me.  What does the internal mod do differently?

Chris

Piratero

Quote from: Jibbajaba on June 23, 2010, 05:24:06 PM
I just use a SCART cable.  Most of my RGB cables are SCART cables with the SCART end chopped off. Works great for me.  What does the internal mod do differently?

Chris

Other than getting the signals directly, I don't know. Is there a noticeable difference (by a human), I doubt it. I have to build me one soon. Composite on the Dreamcast is terribly blurry!!!

RGB32E

Quote from: Piratero on June 23, 2010, 05:59:51 PM
Quote from: Jibbajaba on June 23, 2010, 05:24:06 PM
I just use a SCART cable.  Most of my RGB cables are SCART cables with the SCART end chopped off. Works great for me.  What does the internal mod do differently?

Chris

Other than getting the signals directly, I don't know. Is there a noticeable difference (by a human), I doubt it. I have to build me one soon. Composite on the Dreamcast is terribly blurry!!!

Wuuut??  You don't have a VGA box for the DC?  Ownership of a DC VGA box is a pre-requisite for being a fan of that system.. ;) :P

While making the N64 amp external works, the shortest signal path is best - less likely to pick up noise.  I've noticed that this amp is sensitive to placement when used for NES RGB mods.  I noticed different noise levels depending upon where I placed the amp is in the RGBNES.  Thankfully the N64 provides relatively clean +5VDC and the raw RGB signals are clean enough as well... so you're given some room to noisen things up... not so much with other systems.

RGB32E

Quote from: Jibbajaba on June 21, 2010, 08:41:34 AM
I just finished installing this system in an N64, and the picture looks great!  I had never seen N64 in RGB before, and was told that it didn't have a very good picture, but this amp seems to have fixed that problem.

Thanks!

Chris

Congrats on the NJM amp! :D  Glad you're enjoying the result!  Share pictures with us if you will!

Piratero

Quote from: RGB32E on June 24, 2010, 12:24:22 AM
Quote from: Piratero on June 23, 2010, 05:59:51 PM
Quote from: Jibbajaba on June 23, 2010, 05:24:06 PM
I just use a SCART cable.  Most of my RGB cables are SCART cables with the SCART end chopped off. Works great for me.  What does the internal mod do differently?

Chris

Other than getting the signals directly, I don't know. Is there a noticeable difference (by a human), I doubt it. I have to build me one soon. Composite on the Dreamcast is terribly blurry!!!

Wuuut??  You don't have a VGA box for the DC?  Ownership of a DC VGA box is a pre-requisite for being a fan of that system.. ;) :P

While making the N64 amp external works, the shortest signal path is best - less likely to pick up noise.  I've noticed that this amp is sensitive to placement when used for NES RGB mods.  I noticed different noise levels depending upon where I placed the amp is in the RGBNES.  Thankfully the N64 provides relatively clean +5VDC and the raw RGB signals are clean enough as well... so you're given some room to noisen things up... not so much with other systems.

Hahah, don't make me feel bad! I'll hack up a SCART cable soon!

Jibbajaba

Quote from: RGB32E on June 24, 2010, 12:26:24 AM
Quote from: Jibbajaba on June 21, 2010, 08:41:34 AM
I just finished installing this system in an N64, and the picture looks great!  I had never seen N64 in RGB before, and was told that it didn't have a very good picture, but this amp seems to have fixed that problem.

Thanks!

Chris

Congrats on the NJM amp! :D  Glad you're enjoying the result!  Share pictures with us if you will!

Sorry for the late response.  I'll try to take some pictures this week.  Someone else asked me for them as well.

Chris

duo_r


Sorry a little off topic but does anyone know what the values of the green capacitors that were used fro the TG16 amp? And where in the circuit those were placed? thanks!

Quote from: RGB32E on June 03, 2010, 08:58:04 AM
Quote from: Piratero on June 02, 2010, 05:16:20 AM
Just a couple of questions (if you don't mind):

1. What are those ceramic green capacitors for?
2. Are these the correct parts to order?

Thanks for the help!

1. Used for a simple Low Pass Filter - an experiment for use with TG16/Duo, and NES RGB mods... not needed or recommended for the N64.

2. Yeah, all of those look correct.  It's just a matter of getting the right capacitor type (==), value (==), and voltage rating (>).  The items listed in your image all meet the requirements.  You could up the voltage rating on the electrolytic caps from 6.3V to 10V to play it safe.  If a part is dealing with 5V, a 10V cap will be more tolerant than 6.3V...  perhaps someone with more expertice could add more info.  ???  :P