Hi Gin,
Dendrobium amabile is not the same as dendrobium thyrsiflorum. I have both of these plants. At first glance, they look so similar, but when they flower, well, they are completely different. Den. amabile's flowers have pink/purple pigment on the petals/sepals and the lip is not completely yellow (just like the picture that you saw at Jay Pfahl's website). Den. thyrsiflorum's flowers have no pink/purple pigment so the petals/sepals are pure white in great contrast with the dark yellow color of the lip, hence sometimes this species is called the egg yolk orchid. The lip of Den. thyrsiflorum is all yellow (no white).
I bloomed these guys before, they came out just as described.

Have fun.
Cheers. Hoa.