Other Arcade Sound boards and less confusion

My post yesterday discussed the often misunderstood Digital Sound Board 2 from Sega. In this post I will discuss two other Sega Sound Boards, The Digital Sound Board 1 and the Sega Model 1 Sound board.

The Digital Sound Board 1

First I will tell you about the Digital Sound Board 1. I do not have one of these of my own but in research for the DSB2, I learned a bit about its predecessor. The first thing to know is that DSB1 games are not compatible with DSB2 and vise versa. If a game uses one of these Digital Sound Boards you must be using the proper one since they both work very differently. The DSB1 unlike the DSB2 had an even lower compatibility only being used with 3 games total. The compatible DSB1 games are as follows:

Star Wars Arcade (Model 1)
Sega Touring Cars (Model 2C CRX)
Scud Race/Super GT (Model 3 Step 1.5)

So as you can see, this board actually spans 3 generations of Sega arcade hardware. From what I understand, it serves the same purpose as the DSB2 and generates the music for supported games. From what I have seen in pictures, it will need the proper roms on the board in order for it to work with your game. I will include more information about this board if I ever get one of my own.


Sega DSB1 Sound Board

The Sega Model 1 Sound Board

The Sega Model 1 Sound board is a bit of a different animal compared to Sega's Digital Sound board. In Sega Model 1 games that use this board, this board generates all sounds for the game. Without the sound board hooked up, the game will function just fine and play just fine but will lack all sound. The reason for this is that the Sega Model 1 board (or CG Board, as it was known before the Model 2 started development) does not include any sound hardware on board. It also does not contain I/O hardware so a separate I/O board is needed as well for controls. Unlike the sound board, caged Model 1 boards will have the I/O board inside the cage with the main board. This sound board is needed by the following games:

Virtua Fighter (Model 1)
Virtua Racing (Model 1)
Wing Wars (Model 1) Star Wars Arcade (Model 1)
Daytona USA (Model 2)
Desert Tank (Model 2)
Virtua Cop (Model 2)
Sega Rally Deluxe (Model 2a)
Manx TT Deluxe (Model 2a)

As you can see, this sound board was created for Sega's first 3d board, the Model 1. It was used in a few of the early Model 2 games as well as a couple of the Deluxe cabinets. I really do not know much at all about its Model 2 use, since most Model 2 games did not require a separate sound board and none of the games I own are on this list.


Sega Model 1 Sound Board

As you can see above, this is a two layered board. In Virtua Fighter, the top board generates sound effects and the bottom board generates the music. The board connects from its 6 pin CN2 connector to the 7 Pin CN connector on the right side of the Model 1 filter board. That connection allows for data transfer too and from the sound board. Like the DSB2 (on the board itself, not the filter board), The Model 1's power is fed into it in the black CN1 connector. On a normal Model 1 harness this plug will be included and is keyed so it can not be inserted backwards. Sound can be outputted from the Model 1 sound board in two different ways. Each of the board has a set of red and white composite audio jacks along with a 5 pin connector. You can input these into a composite audio mixer or combination mixer/Amp or you can input the 5 pin connectors from each board into your mixer or mixer/amp. My setup came with the 5 pin audio cables and the 839-0542 audio mixer board that would input the audio into CN1 and CN2, then output it from the center CN3 connector. This would come out as right and left composite audio jacks that I would input into amplified speakers. You could alternatively input it into an audio amp and then into unamplified speakers.


Small Sega Audio Mixer

Other than the DSB2, DSB1 and Model 1 Audio board, any arcade hardware I have seen, includes the audio hardware built into the board either coming out of a JAMMA harness or as right and left audio composite plugs making none of this extra wiring and extra boards necessary. I am sure there are other audio boards used in arcade games that I have just not scene. If you are like me and you either hook your arcade boards to computer speakers or your HDTV, the include audio amplifiers with arcade games are not needed as your TV speakers and computer speakers should already be amplified so plugging in the audio directly from your arcade board is perfectly fine. In the case of a Jamma board, which in most cases is already Amplified, you will need a a device that will unamplify the audio and bring it back to line level. If you have seen any of my arcade videos where I deal with amplified boards, you will see that I use something made for automotive to do just that.

The Digital Sound Board 2 Demystified (DSB2)

I get asked many questions about arcade hardware but nothing seams to be less understood then the Digital Sound Board 2. So in this post, I will explain a bit of what I know about the DSB2 boards.

First of all, this board is ONLY used in the following games:

Top Skater (Sega Model 2 game)
Sega Rally 2
Daytona 2
Star Wars Trilogy
Spikeout Digital Battle Online
Spikeout Final Edition (Slightly patched version of the above)
Lost World Special (Full scale attraction version of the game)

As you can see, other then Top Skater, all of the games that need this board are Sega Model 3 games. Keep in mind, if you try to run one of these games without a DSB2, it will work perfectly fine, it will just not have background music, only sound effects. Another thing to know is, a DSB2 board is 100% universal and will work with any listed game, the only thing you must have done is installed the proper sound roms for the game you are working it with. I have received many DSB2 boards, One had Sega Rally 2 roms in it and the other had Star Wars Trilogy roms in it. I got my trusted rom burner guy to make me some Spikeout Digital Battle Online sound roms that I needed.

The Next thing to talk about is the confusion about caged vs uncaged DSB2 boards. The pcb is a fairly small board (as seen below) with multiple sockets for sound roms and many headers for I/O. Some people tend to run the pcb as just a bare board mounted inside their arcade cabinet with pcb feet. While the boards often came from Sega in a small metal cage similar to many of Sega's boards at the time. These cages not only protected the DSB2 but also made it easier to mount or stack if the board was used outside a cabinet. The biggest problem with the filter board on the DSB2 cage is that it reverses the pin headers on most of the inputs. So if you have a 6 pin header where pin 1 on the board was +5, if you have this DSB2 is in a cage, that +5 is now on pin 6 of that input on the filter board.


A DSB2 without cage with wires


Caged DSB2 board

As I had mentioned above, the sound effects are generated by the arcade board itself, but the music is generated by the DSB2. This is achieved by connecting the Model 3 (I have no knowledge of Top Skater's pinout) to the DSB2 via the 7 pin CN9 connector on the far right side of the Model 3's filter board. If your model 3 lacks this connector, you will need to source a filter board with CN7, CN8 and CN9 with populated pins as this will not work without those connectors. From my understanding the sound effects come out of CN7 just like any normal Model 3. CN7 and CN8 will both be used for sound effects if surround sound mode is enabled. If you are using a normal 2 speaker setup, all you need to worry about is CN7. The cable from CN9 on the Model 3 will connect to the CN6 on the DSB2. This connects the 2 boards and lets them send data back and forth. If the boards are running, the lights on the DSB2 should be blinking indicating data transmission. CN8 on the DSB2 filter is for power. The ground, +12v and +5v will need power on this connector or your sound board will do nothing at all. CN9 and CN10 on the DSB2 filter are used for music Output. Both of these (like CN7 & CN8 from the Model 3) would be used if you were using surround sound, only CN9 is needed if you are only using 2 speakers. Basically from here you just need to feed CN7 from the Model 3 and CN9 from the DSB2 filter board into a Mixer and then from the mixer to amp and unamplified speakers or directly from the mixer if you are using amplified speakers. There are many types of mixer boards from ones mainly used in arcade setups to ones used in audio/visual setups. Basically any mixer should do the trick.

The hardest part of of this whole thing is getting the DSB2 and Model 3 boards working properly and talking to each other. Once the lights on the DSB2 are blinking, you can test your CN9 and see if music is playing, and worry about your mixer from there. Of course having proper roms on the DSB2 is needed as well as this whole thing will not work at all if either you have the wrong roms or the roms are burned improperly as the first roms I received for this were burned on the wrong size chips and did not work. If you have any more questions about this whole crazy setup, feel free to contact me and I will try to help you.