I recorded the Rytm and Octatrack with the same 808 kick sample.
I can’t really hear any difference, can you?
Might be a good reason to upgrade my monitors 
The two samples are called Sampler-A and Sampler-B
https://drive.google.com/file/d/0B7GvyOr-FTQYUkRaRW51SEI0VmM/view?usp=sharing
https://drive.google.com/file/d/0B7GvyOr-FTQYQXZibm1HbW8tYTA/view?usp=sharing
I hear quite a bit of difference. Sample A has a lot less high end, and more harmonics in the low/mid area than Sample B.
The click in the attach on Sample B is the most obvious difference to me.
I don’t know the settings of the machines when you did this, but I would say that the LPF of the AR is responsible for the loss in high end, on Sample A.
there are no effects or filters at play as far as I can tell
the Rytm had FRQ=127 and RES=0
a should be the rytm. the default filter setting on the rytm cuts off a little high end.
Yeah, the sharp attack is much brighter on the B sample. The background noise too.