Hi eclipes,
I am quite interested with the 131 dac too. Since I'd confirm a pre owned 131mk2 but yet to listen to it, I hope more people can share their experience. Not sure about Mk3, but the Mk2 is using BurrBrown PCM1793 DAC and National Semiconductor LME49710 op. These are same to 131.1. I am keen on PCM 1793 becuase I plan to diy Twisted Pear COD dac, which use 1794, and LME49701 could be replace Dexa Discrete Opamp from Parts and Connection. I think this will be quite interesting. I am not sure if 131 is a 'current output Dac'. If yes, it is possible to mount on my Tube output stage near future.
Edited by Blackpine - 1/15/12 at 4:51pm