peter,
use this construction:
[phasor~] | | [r arraylength] | | [*~ ] | [tabread4~ arrayname]
where, "arraylength" is the value obtained from the outlet of [soundfiler] when you load your sample.
the speed of the phasor should be set at ( 44100 / arraylength ) to play at a normal pitch (assuming your samplerate is 44100hz)..and multiplying or dividing this value by a scalar you can change the pplayback speed