This is my own personal opinion so take that as a caveat but I would ditch that simplistic "chuff" as quickly as possible! The chuff isn't very realistic (I'm being kind here) and there isn't any bell or whistle! The Annie is perhaps the best value that you will get in Large Scale as it is very near
Spectrum standards for detailing! Bachmann doesn't add sound to their
Spectrum locomotives. Adding sound will increase the cost by $150 or more but
it is worth it!! Unfortunately, Bachmann has chosen to continue to offer this cheap "chuff" unit in it's Annie series of Big Haulers. It doesn't belong in an Annie! It was designed to enhance an all-plastic early version of the Big Hauler by giving it rudimentary sound but has become technologically inadequate for this level of model locomotive. With the addition of a proper digital sound system, the Annie joins the ranks of the other popular Bachmann engines and holds it's own in side by side comparisons!
Here is an Annie with minor mods:
Compare with a modified
Spectrum Connie: