NES frontloader composite upgrade mod, and adding expansion audio
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- čas přidán 27. 06. 2024
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Taking a close look at the composite video signals on the NES frontloader, and doing some super simple mods to improve the video output. All we need is a 75ohm resistor, a 2N2222 transistor, a 1nF capacitor (or there abouts) and a bit of wire. We'll also do the Famicom expansion audio mod while we're at it.
🛍️ Tindie store: www.tindie.com/stores/theretr...
🛠 Tools and kit: / tools-and-kit-77570017
💬 Discord: / discord
😎 Ad-free, early access: / theretrochannel
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Composite mod schematic: / discord
NES 240p test suite: github.com/pinobatch/240p-tes...
OpenTendo: github.com/Redherring32/OpenT...
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0:00 Intro
1:17 Disassembly (and hidden surprises)
5:04 Scoping it out
9:05 Composite mod part 1
16:18 Testing our mods so far
17:39 Composite mod part 2
20:20 Final results
20:55 Dual mono mod
22:34 Why no stereo mod?
24:10 Expansion audio mod
26:37 Expansion audio test (on PAL)
28:43 Future plans
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Thanks for watching! - Věda a technologie
Thanks for this video. Just did the expansion audio mod to my NTSC NES, akumajou densetsu sounds amazing, but I'm not sure I care about any of the other games with expansion audio, still pretty cool to hear an NES sound like that.
Even in Australia the spiders like the nes 😄😄
Very nice. I never knew that expansion audio just needed a resistor between two pins to be activated on the NES. You would think the NES cartridge would just do this mod internally or with a switch.
Technically the cartridge is generating the expansion audio internally but there's no connection from the cartridge port to the audio circuit. The resistor is needed to connect the expansion audio circuit (which only runs to the expansion port on the bottom) to the cartridge pin
It is good that you did not install an RGB mod, as my future PPUdigitizer for lumacode will probably again blow everything else out of the water ;-) But it will take quite some more time to get this done as the PPU is really fiendishly complex.
You've had an hour, is it done yet? 🤣
Oooooooo 😎😎
@@TheRetroChannel
Hi, I’ve watched a lot of your snes repair videos and learned a lot thank you, but I’m pulling my hair out with a few problems, would it be okay to ask your opinion here in this comment section ?
@ronpalmer1371 feel free. If it is SNES related you're better off putting a comment on the SNES repair video. If I don't know the answer, somebody else may come across it. Otherwise there's a link to my discord in the video description
@@TheRetroChannel
Thank you so much,
One snes works perfectly except it will only play half the games I own (all the games work on another snes) cart slot is spotless and it’s been recapped. Burn in test shows no faults.
Second snes has perfect video but sound is awful (sounds a bit like a blown speaker sounds) it’s fully recapped and no visible signs of a problem. Burn in cartridge shows no faults.
Last one shows no signal on TV screen, cart slot cleaned and tested for continuity from rear to slot, question with this one is would it be worthwhile recapping or do caps not cause a no signal black screen ? Is there normally a first thing to check / replace ?
I know it’s asking a lot to diagnose without the item in front of you so I’m only after a very brief opinion, I’ve spent so many hours on CZcams and other forums. What I’ve learned is people like yourself with real know how are few and far between. Again, thank you for any advice, regards Ron
Having dual mono is the best for the nes. Otherwise you end up with only one speaker playing the audio. I had to do fun things like get a mono single plug to dual audio ports. Both as an adapter and as a complete cable.
I really enjoyed this one; even though I don’t have an NES. Nice, clean mod.
I was expecting an animated spider to leap at the screen when the lid came off. 😄
Great video, as always. Great reference info on the composite signal.
If the adding the support for expansion audio is so easy to do, just by adding ONE resistor, it puzzles me WHY Nintendo didn't include that in the NES from the start.
Looks like they intended to support it, but only from the expansion port on the bottom and not the cartridge port. As they never ended up using that port, the circuit remained unused until carts like the everdrive added support for it using an unused pin on the regular cart connector. The resistor just connects that unused pin to the rest of the expansion audio circuit
Mitsumi vs Alps for the RF modulator.
Funny thing is, I have an NES here at home (PAL region since i'm here in Western Australia) where Console 5 was missing a capacitor.
They had me take screenshots and everything as the layout was slightly different to all other RF modulators they listed.
Excellent video signal breakdown on the scope, thank you! Your content always rocks 😊
Thank you, and welcome 😉
The SMB music sounded too fast to my American ears. Is that due to some kind of PAL/NYSC ROM mismatch?
Yeah, Nintendo did "fix" most games for PAL, otherwise they would run way too slow. Although I guess they didn't bother getting it exact, just close enough
mister fpga with hdmi ftw, NES purrproves.
What kind of mic are you using? Sounds good enough.
R0de wireless go 2
I wonder what value the original SMD capacitor was - it looks like it went from the video output to ground, just like the 1 nF you added.
Possibly. My other NES didn't have that SMD cap there so I didn't want to focus too much on it, easier to the remove everything and start fresh
Is the japanese audio of Castelvania III in the code of the american cartridge? I thought that sound was only possible due to the VRC6 chip. I‘m confused. 🤔
The everdrive emulates the VRC6 chip and outputs the expansion audio on one of the unused cartridge pins. The resistor connects that unused pin to the internal audio circuit
Hold up - all we need to do on NTSC for expanded audio is bridge a couple pins with a resistor? The expanded audio will pipe through the regular ol' output jacks as usual?
Yes, assuming you're using an everdrive
@@TheRetroChannel indeed! N8 Pro. I'll have to give this one a go! I wish getting RGB out was that easy 🤣
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