I don't know, but it's not like feature is going to 'broken' on you mpc. If you do it correctly, it has to work.
Maybe you are not making the setting on the correct pad?
Maybe your sample is too long / not long enough?
Are you sure you are in the right bank before you hit the 16 levels? After? (Not sure if that makes a difference).
Does your velocity work at all?
You have to be sure that Velocity->Level is at 0, and Velocity->Start is at 100 (he does not actually show that step).
I have done everything in the video just as he did.
If you do that it won't work cause he doesn't show that step ;]...it's already set in his vid.
Also, do you have your sample properly trimmed in the TRIM page? Does the original start happen at a useful spot (no silence)? Is there a ton of silence at the end of the sample? Trim off ALL the silence! That could be having an effect.
Just be super careful when doing this and pay attention to what you are doing so you dont maybe accidentally hit another pad.
Hit the pad with the sample on it the whole time so you can hear the changes.
Hit the pad...did you hear the sample start at the beginning? (NO SILENCE).
Turn OFF full level.
Hit the pad (keep tapping it...you should still be hearing the sample from the beginning).
Go into PGM edit (keep tapping the pad, make sure it's the correct pad).
Hit OPEN WINDOW on the attack or decay param (keep tapping that pad...just so you know you are affecting the proper sample...is your sample responding to velocity...getting quieter with softer taps?).
Now set Velocity->Level = 0 (keep tapping that pad...it should now be 'full volume' no matter how hard you hit it)
Now set Velocity->Start = 100 (as you tap lighter / harder now, you should hear the sample start from different points...the harder you hit the EARLIER the sample starts...if you hit it real hard, it should start from the beginning).
That's how you do it.
Those steps might seem a bit excessive but there's obviously some part of it you are missing, so do them all. I am saying to keep tapping it over and over so you can hear the changes as they take place.
is there in fact another way to 'auto chop' the sample over the pads as i am finding cutting down a single sample quite a long process
Not that I know of on a classic (some people made suggestions above). But get used to doing the sample cutting, it's work you just have to do. Also, keep in mind that this 'auto-chop' way of using the velocity -> start is not always going to give you the chops you want...I don't know the intricacies of how it works, but it's not really an 'autochop'...it's just a clever hack of a function that was meant for something else, and it's not very tweakable...you basically set it to the different, static, values, and either take what it gives you or try a different setting.