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If you run DC probably not. The reason is that the sound system steals some of the power from the loco so it will not run at the same speed range as the non sound loco.
I would suggest you give it a try by running one behind the loco. If the speeds are close, just put the faster one in front. If it pulls away from the slower one relatively quickly I wouldn't try it.
Now if you ever move to DCC it's much easier since you can adjust the speed of the faster loco to match the slower one.
Springfield PA
hi there. i'm new and have a question. upon gazing at the atlas website on loco's, there was a statement like: you cannot MU a sound equipped loco with a non sound loco because of the higher starting voltage of the sound unit. that kind of burst my bubble. i have a couple proto and I-M sound loco's and a bunch of non sound. does this pertain to DDC only? i run DC only with a Quantum engineer for the sound. can i MU engines with that? thanks, mike rajchel