New Dimensions in Digital Sound Technology TM APPLICATION NOTE Bachmann 2-6-6-2 Digital Sound Decoder Installation Notes Overview This application note describes the installation of a DSD-090LC Digital Sound Decoder into a Bachmann 2-6-6-2 Locomotive. All of the components are installed inside the tender. No major mechanical modifications are needed and the entire installation should only take a few hours. A 1 speaker is installed under the coal load. The sound decoder is wired to a standard 8-pin NMRA connector and plugs into the DCC ready connector in the tender. Bill of Materials Stock No. Description 821102 DSD-090LC Digital Sound Decoder 810054 1 Speaker 810119 1 Speaker Gasket (Pack of 4) 810012 Two-pin Microconnector 810037 Heat-Shrink Tubing 810123 NMRA-type 8-Pin Header (pack of 4) Tools You Will Need Miniature Screwdriver Set X-acto Knife with #11 Blade 1-1/2 x 3 x 0.040 Styrene Sheet Flat Black Paint RTV or Silicone Sealant 1/4 Drill 7/8 Forstner Bit or Spade Bit Miniature Files Wire Cutters Wire Strippers 25W Solder Iron Rosin Core Solder Heat gun Tweezers Double-sided Foam Tape Pin Vise or Electric Drill #65 Drill Bit Photo 1 Installation 1. Remove the tender shell by unscrewing the small phillips head screw on the bottom frame center, near the back of the front truck (Photo 1). Set this screw aside. Slide the front of the tender shell forward until you can slide the two tabs at the back of the tender out of their slots. 2. The coal load is a separate piece that can be removed by sliding a knife blade under the back of the load and then gently prying the plastic part loose (Photo 2). 3. With your X-acto knife, cut out a piece of 0.040" sheet styrene that measures 0.60" x 0.25". Paint this a flat black and glue over the Photo 2
opening at the bottom of the coal bunker using RTV. Photo 3 shows test-fitting the piece of styrene before painting. Gluing the template to the sheet styrene first makes the measuring and cutting easier. Use the spade bit to drill the large 7/8 hole (Photo 5). If you do not have access to a Forstner or spade bit, you can drill several smaller holes and trim the excess away with a hobby knife. Photo 3 4. Drill a 1/4" hole in the back of the coal bunker for the speaker wires and connector. (Photo4) Since this piece of plastic is simply glued in place, it is a good idea to make a small pilot hole first so as not to 'snag' the plastic. Drill from the bottom of the tender shell to avoid the screw boss. Photo 5 Cut and trim the outer edges. Test fit the plate in the tender. File the rear edge at a slight angle to match the back of the bunker for a perfect fit. 6. Cut approximately 2.75" from each of the purple wires on the DSD-090LC. This should leave roughly an inch of wire still attached to the decoder. Strip 1/8" of insulation from both ends of the two 2.75" lengths of wire. Tin the ends and set aside. 7. Trim the leads of the 33 uf, 16V bipolar capacitor to 1/2 (Photo 6). Photo 4 5. Create a speaker mounting plate from 0.040 styrene using the template provided. Photo 6 0.36" Speaker Plate - 0.040" Styrene 1.46" 0.66" 8. Solder one of the 2.75 purple wires you cut in Step 6 to one lead of the capacitor. Solder the other capacitor lead to one of the speaker terminals, putting a small piece of tape under the connection to insulate it from the back of the speaker. 0.60" 1.32" 0.36" 0.88" Dia. 0.68" 0.11" Photo 7
9. Solder the other length of purple wire to the other speaker terminal. Slide a piece of shrink tubing over your connections and shrink with a heat gun, being careful not to point directly at the capacitor. 10. Solder one speaker wire to the solder terminal of the male Microconnector (Photo 9). Solder the other speaker wire to the remaining male Microconnector terminal. Slide heat shrink tubing over both connections and shrink with the heat gun. Photo 10 14. Strip and tin the remaining length of purple wire still attached to the DSD-090LC. Slide a piece of shrink tubing over each piece. Photo 8 11. Peel the backing off of one side of the selfadhesive speaker gasket with a pair of tweezers. Line up the gasket with the rim of the speaker and press into place. Peel off the remaining backing from the gasket. Line the speaker up with the hole cut in the center of the speaker plate and press into place with the speaker terminals oriented toward the tab as shown in Photo 9. 15. Solder of these purple wires to the solder terminal of the female Microconnector. Solder the purple speaker wire to the remaining female Microconnector terminal. Slide the heat shrink tubing over both connections and shrink with the heat gun, being careful not the heat the decoder itself. 16. Following the diagram below, solder the remaining decoder wires to the 8-pin connector. Since you will not be using either the brown or yellow wires for this installation, trim these wires back to about an inch and tape the ends to the side of the DSD so they will not short to anything. Solder wires to cup side of 8-pin connector Motor Right (Orange) Rear Light (Yellow) Not Used Left Rail (Black) Photo 9 12. Slide the two-pin speaker connector through the hole in the coal bunker that you drilled in Step 4. 13. Mount the speaker assembly in the coal bunker as shown in Photo 10. Run a bead of RTV around the edges of the mounting plate being careful not to get any on the face of the speaker. Set aside to let the RTV dry. Right Rail (Red) Function Common (Blue) Headlight (White) Motor Left Gray NOTE: If you wish to use a cam to synchronize the exhaust or use the DSD-090's lighting effects, do not cut the yellow or brown wires! The yellow wire can be used to hook up a tender backup light if you wish; connect one buld lead to the yellow wire and other to the Blue, or Funtion Common wire. The brown wire connects to your cam.) Insulate your connections. 17. Remove the dummy plug on the Bachmann PCB and plug the 8-pin connector into the
exposed socket. The red wire should line up with the 8 marked on the Bachmann PCB. 18. Mate the two-pin female connector on the DSD-090 to the two-pin male connector coming through the hole in the coal bunker. 15. Attach the DSD-090LC to the tender roof, on the opposite side of the tender from the 8-pin connector, with Velcro or foam tape (Photo11). Photo 11 16. Before you reassemble the locomotive, inspect your work for mis-wires, shorts, broken or nicked wires. 17. Before replacing the coal load insert in the top of the tender shell, drill some small holes in the 'coal' with a #65 drill. Space your holes approximately 1/4" apart and drill 30-80 holes at random angles so they will not be visible. Replace the coal load in the tender shell. 17. Replace the tender shell. Be careful that the wires are not caught between the tender shell and the frame. Replace the screw you removed in step one. Complete the connection between the locomotive and the tender by plugging in the two small orange connectors. 18. Put the locomotive and tender on the programming track and check for shorts. 17. CV Programming Most of the sounds from the DSD-090LC will not need to be changed. The default address is 3. You may wish to change the address of the decoder by changing CV1 (see your command station manual for instructions). You may wish to make adjustments to the Auto Exhaust Chuff Rate (if you have not installed a cam). Auto-Exhaust automatically generates an exhaust chuff rate proportional to the throttle setting. Since every locomotive is different, CV 116 is used to match up the Auto Exhaust rate to the locomotive speed and may be loaded with any value between 0 and 127. Higher values will yield higher chuff rates for a given throttle setting. A typical synchronization rate may be computed as: SPD CV Value = 115.9 X DIA where SPD is the locomotive s top speed in scale miles-per-hour at full throttle and DIA is the locomotive s driver wheel diameter in scale inches. If you don t know your locomotive s top speed, you can also estimate it and still get pretty good results. A good rule of thumb is to use 45 MPH for freight locomotives and 70 MPH for passenger engines. Here are some suggestions for CV settings to get you on track. CV 2 Start Voltage 20 CV 112 Articulated Exhaust 129 CV 116 Chuff Rate 34 CV 115 Whistle Selection 1, 2 or 3 The LC Series Owner s Manual Software Release 2.00 is available for download at our web site (www.soundtraxx.com/dcc/docs. html). This manual will give you additional information regarding CV set up and customizing the decoder for your operations.