I am pretty much kicking myself for not buying a Kato loco for the same price from the LHS. The choice was Atlas with decoder or Kato without. Now I have to buy a new decoder anyway, and on top of that Atlas does not have space for a Digitrax speaker.
And to think that I specifically asked the salesperson which loco should I go with, and he had no clue and no advice either.
Oh well, live and learn.
I would highly recommend replacing the Atlas decoder with a DH165AO. It's well worth the cost of $23, trying to program decoders from two different manufacturers in one locomotive can be challenging.
Don
Great advice, thanks very much, guys! Appreciate your time and effort in typing this up!
Most HO diesel locomotives have room in the cab for a small speaker. Take at look at Tony's Train Exchange TDS Mini Oval Speaker (tdsminoval) and the enclosure for it. This is an excellent speaker that requires the least space. It is an 8 ohm speaker which works very well with the Digitrax SFX004. I just installed a DH165LO decoder and SFX004 and this speaker in a P2K GP9 by gluing the speaker and enclosure to the ceiling of the cab aimed down so that the sound escapes from under the loco.
It's not necessary to use this sound decoder with a DH165xx motor decoder but I would highly recommend using it with a Digitrax decoder rather than another brand. It only requires a connection to track power which can be done by soldering track power wires to the two holes provided for the screws (which aren't really necessary to connect with the DH165). You can easily test this by connecting track power to those two contacts and demonstrating the sounds thru the supplied speaker with some kind of improvised enclosure.
I connected my SFX004 this way to program it and change it's address before installing it in my loco. There is a lot more to know about creating an appropriate sound project for the SD-35 but I won't go into that here. :-)
Ensure that the 8 pins on the SFX004 which are normally used to connect with the DH165xx do not come into contact with any metal, you could probably cut them off if you are tight for space.
Digitrax is nice enough to include a speaker with some of their SFX decoders. Unfortunately, it's about a 1-inch round speaker, which is unlikely to fit in most locomotives. (It's probably not bad for a tender-mounted speaker in a steam sound installation.) So, you have to think outside the box, or, in this case, outside the plastic bag. Smaller speakers are available, as are oval speakers which might better fit under a diesel hood.
Until recently, most locomotive manufacturers filled most of the empty space with metal to add weight to the engine. This keeps the wheels from spinning under load, and gives the engine more pulling power. (It would be tough to add working sand nozzles in HO. And forget about it in N.) So, chances are there's a lot of "dead space" in your engine taken up by weight. You may be able to remove some of this weight by machining down the metal framework, and thus make room for a speaker. I did that to a Proto RS-3, and it still pulls well.
It takes an iron man to play with a toy iron horse.
I have an Atlas SD-35 with Atlas decoder #342 (it came pre-installed). Today I decided to add sound, and after reading on Digitrax website that SFX004 fits most HO locos, I got it.
Upon opening the SD-35 loco I noticed 2 things:
- absolutely no space for a speaker!
- SFX004 only mates with Digitrax DH165 decoder. Ugh.
So, what are my options? Buy a DH165 decoder and replace Atlas factory decoder? But what about speaker space? Kato locos come with a hollow fuel tank where you can place the speaker comfortably, but on Atlas the space is occupied by motor mount. And the SD-35 shell is so narrow, I can't fit the speaker vertically/horizontally anywhere.
Any trick I should know?
Thanks.