Bachmann Sound Tips


Posted on Feb 5, 2014

The Bachmann Big Hauler locomotive has improved greatly over the last few years in appearance, reliability and noise level. However one thing that hasn`t improved is the very basic sound system. The system provides a pretty poor facsimile of an exhaust sound in the form of a `chuff` that is synchronized to the engine drivers. The system can`t prov


Bachmann Sound Tips
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ide anything near the pleasing sound of new digital sound systems, but for less than a dollar`s worth of parts and a few minutes labor, the sound can be materially improved. The "profile" of the exhaust sound is much too sharp in an unmodified sound system. Addition of one resistor and one capacitor to the sound board in the tender will soften the attack and delay of the exhaust beat. The frequency response of the system leads to a tinny sound, two more parts can improve the low frequency response. The sound system generates only two beats per driver revolution while real steam locomotives have four exhaust beats per revolution. Addition of two short wires or resistors to the sound drum on the front axle in the locomotive adds the other two beats. The system has the annoying tendency to sometimes hiss continuously when it stops with the sound contacts closed. A simple track power sensor can shut it off when the track power goes away. Each of these changes can be made independently and all are completely reversible. I find that the addition of these simple modifications makes a material improvement to the Bachmann Big Hauler, ones that Bachmann should incorporate in some future model. Often real steam locomotives will generate beats of different amplitude on the forward and backward piston strokes. This is sometimes caused by the engineer adjusting the valve timing to modify locomotive performance, especially at low speeds,...




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