Best mellow sounding 12ax7 for Thor TA-1000 preamp

Hi, i just happened to stumble across this thread. I recently aquired a Thor TA-1000 mkii preamp. (at least i think it's a Mkii) The serial number is greater than 1000, and I read that if that's the case then it's a mkii?? Is there anywhere i can get an owners manual for it, and  If not does anyone here have one that they could make a copy for me? I would be willing to pay for your time and of course the mailing cost. One of the questions I have is what is the toggle switch on the back for? it isn't labeled. thanks for any help! 

Probably not very useful but my mark I serial number is in the 200's. I dont know when the mkII started.

The only switches I could imagine would be either a USB/rca input switch (does it have a USB input?) or a phone mm/mc switch, if the preamp is a ta-2000 with phono.

I have an owners manual I can scan and email to you if you still need it. 

My TPA-1000 Mark II serial number is 231

I actually do have a manual I can scan and email if you still.want it. Old thread, I know.

I own a Thor 1000 with a Khozmo attenuator and V-cap upgrades. The unit came to me with Russian 12AX7 and 12AT7s. These sounded terrible. So I changed to a pair of Telefunken 12AT7s and Raytheon Windmill 5751s. The old stock tubes were much better however I really think that an old stock 12AX7 like an Amperex would be better. I think that the lower gain of the 5751 robs the Thor of a bit dynamics making the Thor less concise. If you want to tone the Thor down a bit I wouldnt suggest Telefunken AT or AXs. My favorite 12AT7 are Amperex.