If you are using the Triton Studio...you should be able to sample right away without any additional hardware.
If you are using the classic or the pro...I believe they are not equipt to sample...Im not too familiar with these joints.
If you are using the Triton LE, you will need a sampler input card installed which runs about 250.00 or so...see below.
EXB-SMPL Sampling Upgrade: Sampling=16bit sampling, 48kHz stereo/mono sampling frequency, 16 Mbyte SIMM equipped, expandable to 64Mbyte, Audio in 1-2, Mic/Line switch, Gain knob, SCSI IF