Vtin,
The 860 has two transformers and a better transport than the 850. The I/O cards are optional on the 850. The input card is about $1K and output card is $500. I recently boungt an 850 for $2100 and I am pretty happy with it. I will modify the power supply and do a few other things to it. Steve Huntley, who was involved in the design of Wadia players is a guest at AVS forum at AVSforum.com in the special guest section. He can probably answer all your questions concerning Wadia players.
The 860 has two transformers and a better transport than the 850. The I/O cards are optional on the 850. The input card is about $1K and output card is $500. I recently boungt an 850 for $2100 and I am pretty happy with it. I will modify the power supply and do a few other things to it. Steve Huntley, who was involved in the design of Wadia players is a guest at AVS forum at AVSforum.com in the special guest section. He can probably answer all your questions concerning Wadia players.