One of the other advantages of a “dummy” unit is that, since it doesn’t have a motor under the shell, it’s idea for placing a sound decoder and speaker into. I have a Stewart EMD FT-AB diesel on order that will have just that feature.
By definition:
“DCC-equipped” - comes with decoder
“DCC-ready” - no decoder but is wired and “ready” to receive a decoder
If it doesn’t mention anything then it doesn’t have a decoder and “may” not be DCC-ready. Most new locomotives manufactured today are DCC-ready.
So what exactly does the speaker play that is in the dummy? I am full of dumb questions but heres another. Does the dummy hold a speaker that plays train sounds, while you hold the controller in your hand? So are there 2 ways to get train sounds…1 with decoder in a train and then it will play sounds directly out of the train going down the track? and 2 by placing speakers in a dummy engine? Again, any help is app.
In steam locos, the speakers are usually in the tender, so that is where the sound emits. I diesels, they can be in the lone unit if so designed, or in an A-B unit, such as the old E and F series (the ones looking a bit like an old DC-3 cockpit up front), the manfuacturers will sometimes motorize only the A unit, and the robot behind it is empty except for the speakers. So, your paddle operates the speaker system and decoder, and also the motor-driving electronics that are in the A unit.
In my case, I have an F2 A/B, but had the motorized B unit de-motorized and speakers added to the cavity. What was not a sound-emitting loco is now exactly that.
I think if I understand your question correctly: You need a speaker wired to the sound decoder in order to “hear” the sounds emitted by the sound decoder. The decoder itself can NOT emit any horns, bells, whistles or chuffs without a speaker of some kind. Having the speaker inside the shell means that the sound will travel with the locomotive around your layout. Does that make more sense?
Thomas the Tank Engine (TTE) is available in both HO/OO and N Scale. Hornby produce the OO Scale (1/76) TTE and they should be available as sets with track and power pack, Packs (eg Thomas, Annie and Clarrabel or Percy and two troublesome trucks) or individually. Brittish rolling stock usually comes standard with Hook and Loop couplers which are not compatoble with X2F couplers that are the standard for the toy train market in the US. Knuckle couplers are becoming the norm from most suppliers now but these are also not compatible with the english style couplers.
Tomy produces some N Scale (1/144 - 1/160) TTE items but I consider N Scale too small for younger children (have two girls 3 1/2 and 2 1/2).
If the layout is primarily for your Son and you then starting off with a basic set and some points (Switches) to provide a siding or two might be a sound option with the ability to expand as he develops his interest. This will keep the oveall cost down a bit.
If the layout is for YOU and your son then go the whole hog but in steps is a good option. A book I still refer to on occasion is HO Railroad From set to scenery by Rick Selby, Published by Kalmbach Books ISBN 0-89024-222-4. This covers buying the trains (set V’s individual items) through to laying flex track and building control panels (low Voltage only, leave the 110 / 240 stuff to the professionals)
I know you have already selected HO scale. But I urge your to reconsider in light of your son’s age, at least for the trains you use with your son. (Like usual, I am bound and determined to learn my lessons the hard way!) Some will argue with me that their child is so much more mature (to justify doing what they want to do) but reality is most 4 year olds would much rather pu***he trains down the track by hand than “remotely control” them. That was even true for me at age 6 or 7. HO equipment doesn’t take kindly to that kind of use, especially the more expensive equipment that looks and performs better; the stuff that’s been recommended here in the forum.
Junior is going to tire rather quickly watching “Dad’s train” do its thing - a train he’s not allowed to touch because of its value and lack of durability in a 4 year olds hands. And it will always be “Dad’s hobby”, and may/may not interest him later on - at age 8 and up.
Get him a G or O27 starter set - and Thomas is/has been available in both sizes - and run it on the floor for the time being. The toy trains are generally built to take it. Then in a few months, put it on a low table, let him place toys and “scenery” for the train to run through (including more than likely staging collisions and testing the maximum safe speed for the curves!). Help him rearrange the track to his own design at periodic intervals. Add a little every year, and before you know it, your son will be old enough - and more importantly will really want - to join you in model railroading in HO scale.
Now, you can buy him a simple freight or passenger car kit, and watch him delight in assembling it. And the knowledge you both will gain of electricity and electronics, carpentry, scaling, and the like will pay dividends all his life. Not to mention the best part of all, he will always remember fondly the time his Dad spent with him. Chances are, later in life he will seek to recreate those moments with his own model railroad.