shmups.system11.org

C2 in the AV Famicom diagram, yes. It appears to be pulling down expansion audio, atleast with Akumajou Densetsu and Just Breed.
If you would like, I can reinstall it and test with Lagrange Point and the FDS to see if this is a consistent occurrence, although I don't have a Namco 163 cart.

I actually may have someone wire up the board so that it uses the NESRGB audio circuit rather than the original, and possibly the expansion audio. I don't believe I have any games that use the expansion audio but might as well if I'm going through the trouble of having it wired up for CSYNC and NESRGB audio mixing. If the NESRGB circuit dampens the pop then well worth it.

So the pop is DC bias being applied to the circuit, you learn something new everyday

Question, would you wire the single audio output wire of the NESRGB to both L and R (Pins 11 and 12) on the multi-out for dual mono correct?

I decided to brave opening up my RGB modded NES and restore the expansion audio channel. This requires adding a resistor between pin 9 and 3 of the expansion connector on the NES motherboard. Many references claim the resistor needs to be 47k, but retrofixes.com claimed better results with a 24k resistor. So I went with 24k and it worked beautifully! I loaded up the Japanese version of Castlevania 3 on my EverDrive and it sounds perfect!

Here's a pic of my complete mod:



The wire leads are wrapped completely around the pins, and then soldered into place after I clipped the excess wire coming off the pins.

To follow up on the flash-cart expansion audio mod:

I've rigged a 2nd NES deck to where I can test multiple different resistor levels and record the results into my computer using stage 1 one of Castlevania 3. I've just finished a direct recording of 24k and 47k, and I now have to disagree with retrofixes.com about 24k being better sound. To me it sounds much too loud whereas 47k sounds closer to accurate. However, my 'control' recording still suggests 47k is too loud, so I'm going to try higher resistor levels until maybe I can dial in the perfect ratio. I've got 56k and 68k on hand, so I'm going to test those next.

I'll report back what sounds the best of the lot.

Update:

I went all the way up to 68k and found the sweet spot was 56k. That sounds the most accurately balanced on the volume level. Here are the results of all the tests I did:

24k: Way too loud
47k: A tad too loud
56k: Sounds just right
68k: A tad too soft

Well, just wire a 24k resistor in series with a 50k log pot and you'll be able to dial in your setting (in the 24-74k range) on the fly.

Could just throw a 100K pot in series as a rheostat and get ~0-100K .

Right, but I'm just afraid 0 could harm the NESRGB audio circuit since it was designed to have a resistor there from the start.

Not a big deal. I just replaced the 24k with a 56k and it sounds kosher on Akumajou Densetsu through the EverDrive N8. However, I will state that the EverDrive is actually emulating these extra sound channels, and its emulation of the FDS sound channel is completely off and sounds like crap.

@ FBX

Glad my old article could help you. Further down the page it discussed using 24-60k range of resistors.
Using Carts vs Flashdrives can vary in volume.


You stated that you found the 56Kohm perfect. Did you know that the Everdrive has 2 expansion audio Levels in the software? Hi and LO.
Which setting were you using with the 56k resistor?


Thanks!

It was default to the "Hi" setting. When I tried it just now on "Lo", I couldn't here any of the expansion audio for Castlevania 3.

Hi guys im new here, i have a video issue with my NESRGB installes on a Twin Famicom, apparently only occurs with the green color , any help is appreciated, thansk in advance =)

some pics of the video, connected through XRGB mini.





pics of the installed NESRGB.

Try increasing the black level and lowering the brightness level in the Framemeister just to see if it removes the background noise.

Maybe the output capacitor is busted on the green channel? Tantalum caps can be a bit sensitive.

in deed it was the capacitor on the green channel, thank you very much yxkalle and FBX for your help.

capacitor removed


here is the new one, nothing fancy


Clean Green


sorry for the delay and the cell phone photos.

Hello all! I just registered on the forum and this will be my first post!

I just got an old famicom (HVC-CPU-GPM-02) and am about to mod this to my liking. I am currently stuck at the options I got regarding the audio. I plan to order the NESRGB with the power/audio board to go with it.

I'm about to add regular controller ports to the console with support for zapper and mic by a toggle switch.

I've also learned that my revision of motherboard has a bad value on a resistor before sending the audio to the cart.
If looking at the circuit on the famicom board I would change resistor R7 on this schematic http://nesdev.com/Ntd_8bit.jpg
Mind, on GPM-02 this value is 43K (checked!)
43K would make sound come out too low before mixing with cart/everdrive.

If I was to use the NESRGB audio circuit and get sound directly from CPU, where do I connect the cable from the mic (with R3 in line) and where to swap resistor(s) for a trimpot? The only thing I found in this thread was the fix for the AV famicom but that fix does not make use of the power/audio board shipped with the old famicoms, right?
A schematic for the power/audio board for the NESRGB would be very helpful!

So, how to do to keep mic and be able to adjust sound level before the mixing with expanded sound from cart?

I believe that SNES SCART cables have caps in them already. So it's safe to remove that cap and just jumper the 2 pads.

I don't think he's using a SNES/GC cable.

@reimon00 glad to be able to help you!

Notised that the NESRGB currently is out of stock. The shop also mentioned an upcoming retailer in Germany. Anyone know when this shop might be up and running?

Also, if mic turns out to be hard to implement into nesrgb audio board, I propably will settle for it just working but not come through to the CRT.. It would be cool still to be able to mix audio levels by a knob.

Anyone have a working NESRGB board spare which a friend to me can purchase?

happy me!

Hi all,

I'm brand new to the Shmup forums, so I don't want to sound like a jerk or anything, but I was hoping someone here could help me out. I have an NES toploader that I would like to have modded with the NESRGB. I'm located in the US and was hoping to be able to send off my console to someone also located in the US. I would prefer to buy a packaged deal, ie whomever I send it to would have all parts on hand to do the mod.

You can look me up on the sega-16 forums under the same name. I am always on-time with my payments and I don't mind working with you to make this an easy deal.

If I'm out of line or anything like that, please let me know. I don't want to be a nuisance on this forum.

Thanks!

Does anyone know when the NESRGB boards will be back in stock? I would like to purchase the board the the replacement toploader AV panel, but I'm having no luck finding an in-stock source.

Thanks.

edit: put myself on the Australian distributors waiting list. Fingers crossed

The website says mid-September.

A year later, and I have this figured out. The console in question contained a 7806, instead of a 7805. The Nintendo parts are all robust enough to merrily chug along without fault at 6V, but the NESRGB is apparently more sensitive equipment.

tl;dr I soldered in a 7805 and now everything works as it should.

<deleted>

tl;dr my first PPU desolder didn't go so well. Learned a lot and will try again.

I was very happy with Yurkie's work on my NES. He's the semi-official modder/distributor for NESRGB in the USA. Strangely though, he operates from Atari Age forums:

http://atariage.com/forums/topic/222002 ... stributor/

Thanks FBX for your help! I found another modder in the US, Wesley Almond, through the NESRGB page. He was one of the recommended modders on the site, so it should go well.

Thanks for not roasting me about my first post. Much appreciated. I'll be sure to let you guys know how this goes.

Thanks!

Thought I'd make a RGB cable while waiting for the kit to get in-stock again.

On Viletilm's RGB cable circuit board, it doesn't seem to be any capasitors nor resistors?

Just a straight connection from 8-din to scart pins, right?

I did a test about a yeat ago now, with 22k resistor...

https://www.youtube.com/watch?v=1GUygyhNw-Y

and 47k...

https://www.youtube.com/watch?v=Jd-s5cmKJOQ

but i now use a pot to adjust the audio level

Did a quick little design for a PCB that would let me attach my USB Blaster to the NESRGB without having to slice up the cable.

The board only provides that the active IDC pins are available, so I plan to simply solder in machine headers instead of having an actual IDCC10, as well as for the JTAG connection. It's also probably the smallest board I've ever designed, having an area of just over 0.55in². Admittedly, probably not really necessary, but I prefer this solution personally as opposed to destructive modification to my, quite permanently attached, USB Blaster cable.