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.