Okay I just had a play in Massive and this is what I did.
Set OSC 1 and 2 to sin-squ with the wt position set to the sine side.
Detuned both by about 0.30-0.80, try different values and see what you get.
If you play a note like F4 now it should be resonating nicely.
I then assigned an envelope onto the pitch of both oscillators, setting it to -24.00 on both, and giving the envelop quite a long attack.
Should sound similar now.
Here's what it looks like.
Dunno if it's exact but yeah. Play around with the settings.