Dash 9 QSI install This is a pretty easy locomotive to work on, just a few "gotchas" Ther is a removeable hatch on top of the body, it's the center section here: Grab the sides of the hatch, and pull up, rocking a bit side to side: You can now see the cover plate inside, and there are 6 screws around the edges. Don'r remove the screws on the smoke unit! Now, using the smoke unit as a "handle", GENTLY pull the board up and away: Yes, there's a lot of wires connecting it... rotate it away from you as shown. Now you can see the socket: In the picture above, the "shorting plug" is still plugged into the socket. It's on the left, the vertical row of solder blobs, it just pulls straight out. When this is plugged in, it directly connects the track pickups to the motors. Below is a closeup of the Aristo main board. I have flipped the picture over so more of the silk screened text is readable. The speaker socket is the 3 pin socket at the bottom right. (only the 2 outer pins are connected). If you look at the silkscreening, you can see it says SPK just above the socket. Do NOT confuse the 2 pin connector to it's left, that is DC power, labelled: SOUND PWR, intended to power a separate sound system. You also see the Aristo "socket" the J2 connector on the left, and the J1 is on the right, with the shorting plug in the socket itself, just to the rigth of the 22UF/35V capacitor. The shorting plug is removed when using a decoder in the socket. After you get the QSI in the socket, and check to see you got all the pins in, then you get a connector for the speaker socket (I believe Aristo sells them, and maybe QSI is supplying them) and connect the 2 wires to the correct terminal screws on the QSI board, which are J2A-1 and J2A-3 for a single speaker. Of course if you are using 2 speakers, you can use terminals 4 and 5 also to the second speaker.