Generally, I don't like to criticize components, but the MkIII I purchased many years ago was without a doubt the most disappointing audio component I've experienced in over more than thirty years as audiophile. Low resolution, transparency, just a boring piece of equipment, hybrid of tubes and SS didn't make it here. Also add, I tried different tubes, isolation devices, even installed IEC for aftermarket power cords, nothing helped.
Audio Research SP9 family
I want to know more about the Audio Research Family. What are the differences among Mk. I, II and III? I learn that the SP-9 family uses only 2 6922- does it mean that the SP9 use tubes in the phono stage and transistors in the line stage (like SP14), or one tube for the phono and one tube for the line? How well was the SP9 accepted when it was new? How does it sound? Is it a good value?