The following represent the active motive power used on my current HO layout, the Barre Branch, a loose representation of the Central Vermont Railways branch line from Montpelier Junction to Barre, Vermont.
Central Vermont 7917
Based on the Atlas S2 model, this sports a Tsunami sound decoder and Sargent couplers.
Assigned to the Barre Branch, and handles local switching chores.
Details and more information on the conversion may be found here.
Central Vermont 3901
An Atlas RS3, this model suffered an almost fatal layout to floor crash a few years ago, but despite some superficial damage, is a good runner. Equipped with a QSI Titan A sound decoder, stereo speakers, and both Kadee and Sargent couplers.
Assigned to north and south bound passenger traffic.
Details and more information on the conversion may be found here.
Canadian National 9028
A Walther's F7A, with a stock sound decoder and equipped with Sargent couplers.
Assigned to through (manifest) freight service.
Canadian National 9029
A Walther's F7B, with a stock sound decoder and equipped with Sargent couplers.
Assigned to through (manifest) freight service.