The Sega Master system. A much maligned console during the 8-bit console wars between Nintendo and Sega in North America. Despite being more powerful then the NES and having a broader color palette the Master System just couldn’t break Nintendo’s strangle hold on the American market and it faded into the background. I remember seeing them off and on growing up, mostly the model II. My cousin ended up having one and I remember playing Shinobi and not wanting to stop. Eventually a bit after the 8-bit consoles prime my mom ended up buying one second hand off a Electronics Boutique (remember that place) employee at the local mall. She paid $50 for the loose console and a handful of loose games including Shinobi and I finally had my Master System although a little late in the game so to speak.
Little did I know at the time that like most times a console from Japan came to North American shores we got screwed. Much like the scenario with the North American NES having less sound channels the North American Master System lacked FM sound that the Japanese equivalent the Mark III had built in. Even the older styling of the Japanese Master System could equip it as an add on peripheral. I would eventually import a Japanese Master System at some cost and effort just to sample these FM tunes in games that which in many cases were superior to the PSG tunes we got outside of Japan. When I moved cross country my Japanese Master System was one of the many items I had to leave behind in storage but as time passed I began to feel the urge to game again on Sega’s 8-bit system and finally I decided to buy a Master System from a local game shop. About this time is when I discovered an awesome site called retromegabit.com and one of the articles detailed how to add an actual FM sound unit to your North American SMS giving it true FM sound just like the Japanese version. I debated even writing this article since the process is already covered so well over at RetroMegabit but I felt that if I could help get a few more people to discover this mod it was worth the effort.
First off you need to order the FM module from etim.net.au. The module is about $75 Australian dollars but it worked out to be about $52 US dollars (exchange rates vary and can change all the time though). This is an Australian site so keep that in mind as far as currency conversion and what not but they do take Paypal and for me shipping only took about one week for the module to arrive. My module is version 2.2 which feature a three position switch to choose between PSG, FM and Japanese/FM.
This is the module and you can see the Yamaha FM chip on board. The three prongs are for a switch that allows you to switch the system’s FM module on and off so if there’s any games where you prefer the PSG soundtrack you still have that option. The card plugs into the rear edge connector on your Master Systems motherboard and the wire running off the board ends in three wires that will require soldering to the board so please keep this in mind when buying the module. To be completely honest the soldering job is extremely easy and even a novice should be able to pull it off.
Other then a soldering iron I would recommend one of these.
The mod requires desoldering a capacitor and soldering two wires where the capacitor legs previously went and this little iron will help with that as you just apply it to the back of the board at the capacitor solder points and use the bulb pump to suck up the melted solder. My capacitor fell right off the board leaving two clean solder points for my wires.
First stop obviously is taking off the top cover of the Master System and then the RF shield under that via a few easy to find screws. I felt the Master System came apart far easier then the NES, especially with no spring cart insertion system to bother with. The area in the red rectangle is the spot on the board we need to work with. The blue rectangle is your edge connector on the motherboard you need to install the FM module on. To make things way easier remove the entire motherboard from the plastic bottom so you can fully remove it and easily desolder the capacitor.
First thing you want to do is scrap off a little bit of the green on the motherboard on the area to the left as seen above in the image. This where our ground wire is going to be soldered on. The capacitor we need to remove is at C37 on the right side of the image. The best method is to flip the motherboard around and desolder it from the rear solder points and it should fall right off the board. Keep in mind if you back out now unless you resolder the capacitor onto the board you will have no sound.
The white wire goes into the point where the + symbol is and the red wire in the lefter solder point close to the C37 label. Note that on the official installation instructions these wires may be accidentally reversed. This image above is the correct orientation. If soldered opposite of this way you will have no sound.
I added a dab of hot glue to each wire end just to help everything stay in place and to put less stress on the solder points. At this point test your Master System with a FM capable game such as Miracle Warriors just to make sure the module is properly installed and your soldering job made a good connection. The sound from both FM and PSG should be clear and strong. A full list of FM sound compatible games can be found here.
At this point before you reassemble the Master system you need to modify your RF shield to accommodate the newly added module.
Just snip away and then either cut off or fold up the excess metal. After this the shielding should go right on.
I decided to drill a small hole in the rear of my unit to install the three way switch. I used a small power drill and then carefully widened the hole with an Exacto knife until the switch fit snugly.
Overall I’m very happy with this mod. The installation took less then an hour and it all looks and works very well. I considered posting some videos with audio examples of the difference between PSG and FM soundtracks but these are easily found on YouTube or better yet make your way over to RetroMegabit and check out his article on the FM mod and sound examples.
As a final note I spied this on the motherboard.
I’m pretty sure a switch to choose between PAL and NTSC can be wired up at this point since many Master System games were PAL exclusive. After further research and talking to NTSC owners of PAL games it seems a mod of this type is unnecessary and PAL games play just fine on NTSC systems. If I can find any examples that prove this false though I’ll be sure to post them here.
ancientelectronics 
6 Comments
Outstanding! Excellent write up. I’m really glad you decided to write about your SMS FM Sound mod. Somewhere out on the Internet someone else has already written about whatever it is someone new was considering doing. And I honestly feel it’s never a wasted effort to write about your own experience.
Just like you, I’ve done this mod and I still really enjoyed reading your article. You did a few things differently and I think you even did a better job at removing that capacitor!
So which are some of your favorite games to play with FM Sound? I know you were able to previously enjoy some FM games on your Japanese SMS but now you can enjoy them in English and I’m sure that opens up a few more options for play; like Miracle Warriors that you mentioned.
Did you find any games that you prefer with PSG sound over the FM?
thanks! I haven’t had a chance to try out that many as my master system game collection is rather sparse at the moment. Miracle warriors I do like better in FM. Phantasy Star is up in the air but I think that’s just because I’ve grown a nostalgic attachment to the PSG soundtrack. The other issue with the Japanese master System was the cartridge slot is different so you have to use a converter which makes it look kinda ugly and awkward with a game inserted.
I really like how you’re giving the system so much love. I’m not overly familiar with the Master System but I really like when people show their appreciation to the system. The Mark I design is superior in my opinion, and I’d choose it myself if I ever were to buy a system of my own. I’m opting for the Master System Power Base Converter for the Genesis/Mega Drive I instead, if only to save on console space. I have two slots left on the shelf, and one is reserved for a SNES and the other probably for another system (an Xbox of some sort or a newer PS system perhaps?) though I’m not sure at the moment.
I struggled over a master system or a power base converter myself. with a SMS controller the power base should be 100% compatible but as far as I know the original converter or the genesis cant be FM modded or at least no one has cared to look into it (that I know of). There is a third party newer power base converter with FM built in but no slot for card games. so in the end although it takes up more space I get the whole SMS experience with a actual system plus I like the look and it makes a good conversation piece since its easy to spot and most people aren’t familiar with it. I never cared for the original Xbox but that’s mostly an issue with games and not hardware. It just didn’t have the types I really liked but overall there are plenty worse systems. The Xbox 360, now I actually really liked that console once they got the red ring of death thing worked out.
A SMS might be the way to go, and the games are very cheap too. I’ll have to check into that once I feel that my DC and Mega Drive collection is close to what I’d like them to be.
From what I understand it was much more popular in Europe then North America or Japan. Actually for once we got more games then Japan did in the US but PAL territories got even more and some really good ones at that.