NES frontloader composite upgrade mod, and adding expansion audio

Рет қаралды 3,675

Күн бұрын

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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
🔗
Composite mod schematic: / discord
NES 240p test suite: github.com/pinobatch/240p-tes...
OpenTendo: github.com/Redherring32/OpenT...
🔗
🎞
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
🎞
Thanks for watching!

Пікірлер: 41

@vk3hau 3 ай бұрын

Even in Australia the spiders like the nes 😄😄

@somanymods Ай бұрын

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.

@CoolDudeClem 3 ай бұрын

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.

@TheRetroChannel 3 ай бұрын

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

@tspawn35 3 ай бұрын

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.

@herbertwongsanimations6266 3 ай бұрын

I was expecting an animated spider to leap at the screen when the lid came off. 😄

@copperdragon9286 3 ай бұрын

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.

@TharkysOlafson 3 ай бұрын

You've had an hour, is it done yet? 🤣

@TheRetroChannel 3 ай бұрын

Oooooooo 😎😎

@ronpalmer1371 3 ай бұрын

@@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 ?

@TheRetroChannel 3 ай бұрын

@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

@ronpalmer1371 3 ай бұрын

@@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 KZfaq 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

@mk500 3 ай бұрын

I really enjoyed this one; even though I don’t have an NES. Nice, clean mod.

@robbyxp1 3 ай бұрын

Great video, as always. Great reference info on the composite signal.

@ray73864 3 ай бұрын

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.

@sweetlilmre 3 ай бұрын

Excellent video signal breakdown on the scope, thank you! Your content always rocks 😊

@TheRetroChannel 3 ай бұрын

Thank you, and welcome 😉

@jandjrandr 3 ай бұрын

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.

@TheRetroChannel 3 ай бұрын

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

@Nukle0n 11 күн бұрын

it looks like you have a bit of wobble on the horizontal sync, the edges of the screen are like a sawtooth

@CygnusTM 3 ай бұрын

The SMB music sounded too fast to my American ears. Is that due to some kind of PAL/NYSC ROM mismatch?

@TheRetroChannel 3 ай бұрын

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

@GuiOmania 11 күн бұрын

The nes really have bad av i got the Famicom AV from japan and i was shock at the image quality it use the snes av port and its insane the difference between the original nes ,i got a convertor so i can use nes game with too love it best nes by far !!!

@kenny9648 2 ай бұрын

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. 🤔

@TheRetroChannel 2 ай бұрын

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

@gsestream 3 ай бұрын

mister fpga with hdmi ftw, NES purrproves.

@Kamnaruun 22 күн бұрын

Can't compare to original hardware 😅

@shangrilai1990 3 ай бұрын

🍪

@TheRetroChannel 3 ай бұрын

🤓📺

@Ragnar8504 3 ай бұрын

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.

@TheRetroChannel 3 ай бұрын

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

@Kamnaruun 22 күн бұрын

Mine 220pf.

@wardrich 27 күн бұрын

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?

@TheRetroChannel 27 күн бұрын

Yes, assuming you're using an everdrive

@wardrich 27 күн бұрын

@@TheRetroChannel indeed! N8 Pro. I'll have to give this one a go! I wish getting RGB out was that easy 🤣