Is anyone using Roman's sound encoder software ? I actually have both versions. His webpage has the old dos version, but he sent me a windows version that was never released to the public. The original was encoder.exe from 12/20/01. He sent me BTc.exe from 10/4/02. BTc.exe gives you an option to select the algorithm 1bit or 1.5bit. Also, the fineness from BTc4 to BTc32. It also allows you to play the original sound and the BTc sound to compare the quality. As well as giving you the values for R and C for the output filter model. If I have time tomorrow I will put together the circuit sent to him by Christian Dorner. To compare the sound from BTc.exe to the actual pic circuit. If anyone wants the Btc.exe I can send it to them, it's a 360KB zip file. ~Kevin -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist