Proper NES Frontloader Expansion Audio for Tim's RGB kit

[the_crayon_king]

So I have made this mod about 5 times now and am pretty certain it is the best way to mix audio on a RGB modified NES frontloader.

In the spirit of writing things down before I forget I decided to make a post on it.

 

Parts needed:

1. Tim's RGB Kit

2. 2x 1uf 50v capacitors

3. 2x 47k ohm resistors

4. Karaoke Mixer : Dual Microphone, Stereo Music, Stereo Output, Balanced (here)
5. Wire and stuff.

 

Sloppy Notes:

0. Drill holes pretty high so that you don't hit the bottom of the cart slot.

0.01 You will have to cut a slot into one of the plastic screw mounts of the NES. Place the mixer so that you only have to cut the middle mount.

0.1 You can cut the top rail of the slot if needed as it doesn't seem to do anything.

0.2 Leave off all shielding from console.

0.3 Use the mixer as a template for holes.

1. Suggest you power the thing off of the 5v out from the RGB kit or else use the power reg. Can use DC voltage of 5-12v (something like that idk) may need a higher amperage 7805 IDK

2. Both CPU pin 1 & 2 are still mixed into the RGB kit for mono out.

2.1 The mixer has three inputs: one stereo, two dual mono.

3. Of course desolder all the power, inputs, outputs that are on the mixer.

4. The two dual mono inputs need 47k ohm resistors as close to the mixer as possible.

5. The two stereo lines need 1uf 50v caps much the same near as possible to the mixer. + towards the input pad.

6. Use pin 9 of the expansion port to get expansion audio. (DO NOT BRIDGE TO PIN 3 AS MOST MODS DO)

7. Stereo comes from the CPU pin 1 and 2 (or just jumped from the same pins as the audio input to Tim's board)

8. Mono is coming from the 0 pad on the RGB kit.

9. I used only 1 ground input from the same area I got power.

10. Lots of hot glue or heat shrink or electrical tape. Don't let your lines short to ground on the mixer.

 

I mostly made this post for me to refer to in the future but if you have any questions just ask and Ill try to explain.

Im probably too lazy to open this back up atm but I believe I have some pictures from all the other times I have done this someplace I will look...

 

Video (will be live in a bit):

https://www.youtube.com/watch?v=L1wUiwDjbIE