atlas sd35 overviewAug 16, 2008


  1. 678-827101 Tsunami DCC Sound Decoder by SoundTraxx 
    [2020 note, use Tsunami2, part number 678-885022.]
  2. 30 mm (1.17 inch) Round Speaker 1 watt rated Qty = 2
  3. 269-9515 Styrene Black 0.04 thick
  4. Shrink Tubing 1/16 inch 1 yard
  5. Kapton Tape 3/8 inch wide one yard
  6. Bathtub Caulk
  7. Gray Foam Tape
  8. Nano-Oil 5, 10 & 85 wt
  9. Never Stall

 This loco was designed for sound. If you bought one without sound, here is the easy way to give it a voice!

The photos show the older speaker only rated at 0.05 watts. Bruce used one resistor between the speakers to wire them in series. Since this installation was done, higher wattage rated speakers have become available. Use the higher wattage speakers without the resistor.

atlas sd35 speaker detail

The two speakers were held into the mounts with bathtub caulk. Be very careful not to get it on the speaker cones. All seems fine sound wise on this install. Remember the shell is an integral part of the acoustic design of this installation. The sound will change (improve) when the shell is installed. These speakers are a bit thicker than the ones that the loco was designed for, you MAY need (or want) to trim a bit of the shell for a good fit.

The diesel Tsunami decoder fits between the weights. We removed the Atlas board and installed a styrene shelf using double sided tape. The diesel Tsunami was mounted on this board along with its capacitor (with the leads shortened). The pick-ups, LEDs and motor were wired with the leads from the decoder with the majority of Atlas' wires being discarded. Kapton tape holds the wires in place.

atlas sd35 decoder detail


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Information on this site represents Bruce’s experiences and opinions. They are presented without warranty as an example of ways to utilize DCC products. The user is solely responsible for any use made of this data.