Lpcm encoded data kept on an analog source Let us say i have some digital data placed in a wav file by lpcm method. At a sampling rate of 44.1khz i can place 5.5kb of data per second of audio by choosing two amplitudes (quantas) for each sample: 0 and 255. I can now save this audio file on an analog media and can retrieve the original digital data easily later. My question is this: What is the maximum number of quanta I could have used instead of 2 in the beginning so as to guarantee the integrity of my digital data on an analog media?
The theoretical max number of bits you can get is function of the bandwidth and the signal to noise ratio of your media. It's often referred to as "Channel Capacity", see
http://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theorem

In practice this depends a lot on the specific properties of your channel (transfer function, noise properties etc.) and there are many technologies you can deploy effectively deal with these properties.