More detail required on standard PAL MD / SNES mods (MODEL 1)

Started by codemonkey1980, July 19, 2009, 08:13:28 AM

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codemonkey1980

Hi there....Noob here requesting further detail on standard MD/SNES mods ;)

I'm new to the scene of modding, and have only basic electronics knowledge / skills etc, yet have found the standard mods available for my selected platforms to be very straightforward...I have read what subject matter I can find online, and now possess all the information required to complete my selected mods, yet am kinda bugged by not knowing how certain things work! Before I go into details, I'd just like to note that I aim on creating a detailed online guide on the mods I am attempting, and therefore any contributions to my research will be used to aid further potential modders down the line, and very much appreciated by myself!

Ok...Following are the consoles and mod details:

PAL MegaDrive (Model 1) ~ Language & 50/60Hz switches / RCA Phono connections added to the back of the case (connected from the solder points located near the headphone jack, i.e. 1,2,3) / Blue LED mounted

PAL SNES (Model 1) ~ Lockout & 50/60Hz switches / RCA Phono connections added to the back of the case (connected from the solder points located on the PCB, i.e. 4,11,12) / Blue LED mounted

Soooo, pretty standard mods :) I basically collect JAP games for each platform so the switches on both machines will address the region / speed issues for this...I also like having the option then of recieving the stereo sound from either the TV via RGB, or via the RCA connectors hooked up to an amp (or both lol)...I have focused on the Model 1 releases of both machines as these seem to be the best (simple!) choice for modding, and are easily picked up at low prices...

Now there are just a few things to clear up ;)....

1. Am I going about the audio part of the mods in the best way? I mean I know they will work, but are there alternatives that produce improved sound quality? I ask this after coming across the MD crystal clear mod, however am not interested in anything along these lines, as this obviously requires wiring up a circuit that (while not advanced to many of the experienced modders here), is a step up in difficulty that I do not want to cover in the guide (I wish to keep things simple and concise for people with little to no knowledge!)

2. I have read in serveral guides etc, that on certain MD model 1 boards a capacitor is sometimes placed on JP1/2 dependant on the console region...Now, the big question I have is what does this do? and what to do in this scenario? I came across a post from a modder who was having problems with his MD switches working correctly with the capacitor in place, so he removed it and everything ran perfectly afterwards...So what is the point of this capacitor and is there any harm in removing it? Logically, having it there suggests it is simply meant to block the intended GND/+5V from reaching the common terminal, but then why use this method when standard MD PCB's just have the appropriate trace connected, and the others left open?...Lol, and if a capacitor is used on JP1/2 to control the language setting, is a similar one used on JP3/4 for speed setting?...The mind boggles...

Well that's basically it!...If someone can at least inform me of the deal with Q2, then I assume my guide will cover all variants of the PAL MD/SNES Model 1 board revisions, bar the later model 1 SNES boards with combined PPU1/2 (and perhaps any others I may not know / have read about?)...***I don't intend including information on the mod for a combined SNES PPU chip, as again that is beyond the scope of my guide...

Finally I'd just like to thank anyone who takes the time to read this! And many thanks in advance to anyone who can help out :)


codemonkey1980

It seems through further googling and spending hours searching through forums etc, that I have half answered my first question!

I am asuming that the audio mod I intend for the SNES by getting the L/R/GND from the (multi-out) solder points on the PCB is the best way to go about getting stereo RCA connections setup, although I did read from one modder that you should then disable L/R from the RGB output if using RCA connections in this manner? I can't see why I would have to, as it would be best to have the option of just recieving sound through RGB/TV and/or running the signal through an external amp (as with my outlined Megadrive setup). Nonetheless, this is the method I intend to use unless someone here can suggest otherwise, or give a valid reason for disabling the sound from the RGB output (perhaps the signal degrades running to both the added RCA jacks and through the RGB?).

With the megadrive audio, as I stated in my first post I wish to keep things simple for my first project (so no crystal clear mod yet!), but I have read that getting the signals from the solder points near the headphone jack (1,2,3) is not the most desirable option due to the signal being amplified at this point (causing distortion), and to take it from the legs of a certain chip instead? I can't seem to find anymore information on this apart from the vague description...Now, unlike many of the guest / noob posts you get here, I kinda know what I'm doing (famous last words), so I don't need anyone to hold my hand lol, but I would be very grateful if someone could point me in the right direction for this particular mod i.e. chip location / pinout, and basically any other helpful advice on the whole in relation to my query.

I'd just like to say thanks to all the modders here who contribute to the site, I have found the information I have come across extremely useful for my upcoming projects, and I look forward to working my way up to tackling some of the more complex mods possible for some of my favourite platforms over the coming years (though I think acheiving a Neptune style mod anytime soon is hoping a little too much perhaps ;) lol)

Thanks in advance,

Gavin