It a 4 partial sound - generally impossible to exactly re-create on the TI, but in this case were lucky as one of the partials is basically coloured noise. The rest are a couple of samples (tinkly bell and an organ) and a square wave.
As these are samples - then effectively they each have separate envelopes if you are trying to synthesise the result. *may* be able to get close - but I think its a complete b*****d to reproduce on a synth that doesnt effectively have per-osc amp envelopes or equiv because of a sample having its own volume envelope.
Should be able to get close I think by using a one shot LFO as an env gen on say osc 3 volume to make the bell, but probably really needs a wave table so LFO driving osc balance may not work so well (because the wave would on on osc 2).
I think the rest may be able to more or less follow the normal amp env + filter env. Probably use split filter mode as well so the organ gets its own filter and the rest share.
Ill have a go this eve when I'm home