Darrenmb, hi. I also have a lot of old locos, and use H&M controllers. I looked into this in great depth, when looking at DCC, and all the advice was, that unless these locos run perfectly, they will not make the transition to DCC. With this in mind, as they were of great sentimental value, i decided to run 2 layouts. The upper one, being DCC, with new locos, leaving my old friends, as DC, remaining with old controllers. That way, there running/ value is not affected. They would all have need extensive soldering, and the finished result, was not guaranteed. Contrary to popular belief, DCC, is not compulsary, and many , many peopls still happily run DC. I only started DCC, as following illness, was unable to go ypstairs for many months, and had DCC, downstairs. Happily, i was then able to resume, hence, upper layout. DCC, is not cheap, the decoders, controller, point decoders, etc, all add up, and you may find yourself in a can of worms, if these dont/ wont convert. Sound decoders, in particular, are quite expensive, and well may not match your existing locos. I would be inclined to keep your inherited locos, as are, and enjoy them, for now. .If you want to dip your toe in DCC, you could pick up a starter set. I did. .