Create a tanpura sound sample
After tuning properly the instrument to record, record a piece of sound. Your sound sample should be at least a few seconds in length. You can use both MONO or STEREO audio samples. To prepare the sound sample for playing in a tanpura, remove the silence at the beginning and the end:
Beginning and ending should be very clean, without extra silence or noise. Normalize the sound to nearly 0 dB and then export it as an AIFF or a WAVE file, 24 bits if possible (recommended maximum duration is 16 seconds).
Create a shruti box sound sample
After tuning properly the instrument to record, record a piece of sound. Your sound sample should be at least a few seconds in length. You can use only MONO samples for the moment.
To prepare the sound sample for playing in the shruti box, select a part which is looping without cracking (difficult exercise). Do this in your DAW: Cubase, DigitalPerformer, …
Normalize and then export the selected part of the sound sample in an AIFF or WAVE file, 24 bits if possible (recommended maximum size is 16 Mb and 32 seconds).