The Micro Tsunami would fit. Just measure the motor current first.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
The new Tsunamis are way better than the older DSX decoders. Better even than the DSD ones that came later. Make sure you check the motor load if you are going to use one of the new Tsunami 750's. They blow the internal fuse easily and cost $45 to get repaired. The Tsunamis are motor and sound, as I believe the DSX's were.
I mounted my decoder in the tender but I had to do away with the decoder connector in there because the extra room was needed, and I had to remove the light as well. I mounted a .75 diameter speaker with enclosure in the cab on the backhead. (The newer Bachmann 80 ton Shays have a circuit board and are DCC ready with an 8 pin connector.)
As for the installation, do a search on the Internet. You may be surprised by what you find. There are a lot of people documenting their decoder installs, and with pictures too.
And, the bevel gears on the drive train had a problem cracking on their shafts, so make sure the Shay runs smooth before you start. NWSL has a repair kit for the gears that is well worth getting.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
Can remember years ago articles on installing a Soundtraxx DSX sound system in an original 80 ton Bachmann HO Shay. I've just come ashore after years of cruising (without any trains!) and am digging out my old purchases from 2001-02 (including a never-used Lenz Digital Plus 01/4). Can anyone remember the back issues with these articles? It looks like a very very tight fit and I still don't know where the motor decoder goes but I remember somebody did it! If I have to, I'll E-Bay the DSX and buy a new small Tsunami decoder. Is the Tsunami a whole lot better than the old DSX? Any articles on installing it in the HO Bachmann Shay? Thanks in advance, now where does the layout go...