Mike I did something similiar to you using a BLI decoder out of my 2-6-6-4 A unit when the motor fried. I changed from steam to deisel using decoder-pro quite easily.
NickyB
That would work. However the sound will be further away from the engine. I took another approach when I converted my Westside SP P-10 to DCC. I was able to cram everything into the engine boiler area. I used a Tsunami 750 decoder. I also converted to a can motor at the same time. So with a careful selection of componets I was able to make things fit and have a very nice running engine.
My biggest challenge was converting my SP 2-6-0 with a Vandy tender to DCC. I wound up putting the speaker in the roof of the cab area. Worked out real good.
Mike,
The Digitrax SFX004 Soundbug would seem to be a good fit for what you're looking to do.
It comes with both a "generic" steam sound scheme and an SD38-2 sound scheme (selectable by CV).
You can also download other sound schemes to it (requires either a PR2 or PR3 programmer from Digitrax.)
EDIT: Added link
I have a SP/TNO 4-6-2 brass locomotive that is due for a DCC install. I'm thinking of motor function only since I'm not sure the Vandy tender will easily accomodate a sound decoder and speaker without serious surgery.
My current thinking is to put a sound only decoder in a SP Overnight Express box car that would be hauled headend. I'm thinking about also having this car available for use in a Cotton Belt PA consist, so I'd like a decoder that can go both steam and diesel. Anybody offer those and do any of you guys see a problem with this idea?
Mike