The linestage is 12at7, call pac valve and talk to Joe or the tech. Apparently there is no schematic available and they are tight lipped about the circuit. I found that the pair to the right looking from the front to be the most sensitive to noise in both phono (12ax7) and line (12at7) but that is very subjective. I ended up using a quad of siemens ecc801s in the line stage which takes the amp to an even higher level of performance.
