I have the 859 and it is wonderful with the right speakers, as noted by Pubul57. The speakers have to be VERY sensitive I find (personally, I would say 98db or better).
The 859 is the precursor to the 869. There is an extra tube in the preamp section of the 869 which gives it a little more power (15W instead of 13.5W of the 859). Apparently the output transformer was slightly modified as well, and the 869 has the function of being able to bypass the pre-amp stage and use it only as a power amp (which the 859 cannot do).
