I just received a written confirmation from Kevin Halverson that the iDSP contains in fact the Burr-Brown (TI) PCM5102 DAC chip.

I gave HRT a call and was told it is a Texas Instruments DAC but they are unable to disclose the part number.

Hey there. I was at the same place as you a while ago, searching for a similar speaker, within the same budget. I had a listen to the LS 50 and I was so amazed, I just had to bring that "sound" home. Actually, I did not even get to listening to the Qs and Rs!!! I made an unboxing video recently...