It's a factory fitted decoder. Which makes the installation easier - I've yet to find one that works as I'd want it to straight out of the box. In the case of this one the running needs smoothing out (looking for a good balance between inertia and control; and it must synchronise with the sound), the speaker will be replaced and fitted to a bigger enclosure. I also need to get backup lights installed - so I've got to see if there are any spare connections on the decoder that would suit.
I'm generally 'sold' on ESU LokSound decoders as I find all the criteria above relatively straightforward to set up. To the point that I bought the LokProgrammer and can now load my own (or tweaked) sound profiles on to decoders.
For sound decoders there are a couple of issues associated with installation; the principle one from our perspective is where and how to install the sound chamber. Then there's space for the decoder and then lighting effects.
Sound decoders are available from a variety of sources. I've indicated my support for ESU although my experience is limited to v3, v3.5 and v4. The 'Select' range look good value and seem easy to install so might be worth a punt. Then there's QSI; I've had no luck with the early versions (up to v6, inclusive) although these can been upgraded to latest specs for around £20 by swapping a chip on the decoder. The FP7 I'm playing with is v7 and seems much better than of old. I'm not quite where I need to be, but the slow speed running is already much better than earlier versions. And then there's Soundtraxx. These seem to have a really good reputation in the US, but I think that has more to do with the clarity and dynamics of their sound, rather than for their running or synchronisation. However, Yorkshire Dave has done some work with a recent factory-installed one (Intermountain SD40-2w) and tells me he's got it working properly.
For decoders in general I don't recommend TCS. Lenz Gold, Silver, anything by Zimo or the ESU decoders are all I use these days. All of these are a breeze to fit to any DCC-ready loco, but need some care (and hard-wiring) to fit to anything which isn't DCC-ready. If you're looking for a decoder to drop out the existing circuit and drop in a new one then NCE is worth a punt. They don't run as well as those I've suggested, but the installation is quick, painless and running would be good enough for most people.
Any help?
Steph