Replace Classe CA-200 with Pass X350, do it?

Depends on the age and price. >15yo units would need to be serviced and brought back to their original specks for another toll of investment. Units younger than 15yo will also need to be serviced after a while. In both cases count on extra money to spend, if you want to keep your unit safe and in good condition.

The Pass will be a much better match for your 850. Chances are that you may like it better without the ARC in the way.

Thanks guys! I thought it would be tilted towards Pass ;-)

Jl35, why the debate on the X350?

If I had your equipment the power amp would be the next to last item I would change. I think you would a bigger bang for the buck with a better preamp and/or switching to a full ribbon Maggies.

Many Pass fans preferred the 250 to the 350, thought the 350 was not quite right. Many threads here on that.