I am asking this question to see how you feel about the sound decoders that come in the MTH SD70ACe’s and SD70M-2. I have read where some modelers prefer to put their own decoders in these locomotives. I have also read that you don’t get full access to the decoder features with a regular dcc system that you would normally get with a DCS control system.
I am looking to purchase a couple of these units with DCC and sound but want to know if I am getting my monies worth. I have a NCE DCC system that I will be using with them. If anyone has these and uses NCE DCC system please share your experience.
The best thing to do with the SD70 is get the DCC ready version and install a Soundtraxx decoder with a couple of speakers. I picked up 2 of the proto 3.0 before the DCC ready was available. They sound and run good but the lack of individual sound controls, default master volume, as well as the ability to speed match with non MTH loco’s. I believe the newer releases have included more CV’s but not sure which one’s.
I own several MTH SD70ACe’s, one SD70M-2, and several other MTH HO engines. All of my MTH engines are equipped with Protosound 3 and I run them with NCE DCC. They are smoothest running and best pulling engines I own. I have never had any problems programming or operating them with my NCE Power Pro system.
Early releases of the SD70’s did not support advanced consisting, custom speed mapping, or function mapping in DCC. All newer released (since last February) do support these features in DCC. All MTH SD70’s that were shipped without these features can have them added with a free software upgrade. Loading the updated software requires an MTH DCS system. If you decide to purchase one or more engines I’d recommend checking with your dealer to ensure the engine has the latest software update. Any reputable dealer should be able to upgrade the software for you before you buy.
The PS3 is one of the better sounding decoders on the market, and has BY FAR the best speed control. Every MTH locomotive comes out of the box speed mapped to operate in one scale mile per hour increments when your DCC system is set for 128 speed steps. Set the speed on your ProCab to 21 and the engine does 21 SMPH. This makes it extremely easy to consist MTH locomotives. You don’t have to do any programing of CV’s. Just build the consist and go. MTH uses an optical speed sensor on the flywheel to measure actual speed output. Currently, all other decoders on the market use BEMF to infer motor speed. BEMF works, but it is two orders of magnitude less accurate. You can always speed map other engines to run as close to the MTH speed map as possible. That’s what I do with non-MTH engines. Others prefer to set their own speed curve. Until last winter, you couldn’t program a custom speed map into an MTH engine. That has now changed. Any MTH HO diesel or electric engine can now be c
This works because MTH builds the deocder AND the loco. All other decoders are ‘generic’ in that they can be installed in any loco that has physical space to fit it. You can’t simply add an optical tacho wheel and have it work - you need to know motor RP across the voltage range as well as loco geering and wheel size in order to calibrate it to get 1smph speed steps. BEMF can do this just as well, provided you have the specification for strength of BEMF at a given RPM for the motor to calibrate it.