Duelund 12AWG Biwire Amp runs hot

If your amp is running hot, the current is probably high which means the load (impedence) is probably low  I'm guessing you have something wired funny.  

You can probably check with a simple meter.  

Pull the cables out of the am and measure the resistance.   Now measure the resistance at the speaker terminals with no cables.  Should be about the same.  If the cable is lower, there is something crossed.

Measure the cables not hooke to anything and it should be infinity (open). 

Jerry

Lay one cable out on your table, using a multi- meter or continuity tester, attach a crocodile clip to the red amp side wire and then touch each of the speaker end wires.

You should only get a closed circuit on the red wires the blacks should be open circuit.

Repeat with the black amp side wire, the blacks should be closed and the reds open circuit.

Then check the other speaker cable exactly the same.

Don't run the amp with those cables anymore until you check the cables for continuity (this is the first thing you do with any cable, homemade or purchased). If you don't have continuity on one or both cables, the tube amp cannot see the speaker load and things will run hot, tubes and output transformers. 

Thank you all for your thoughts and answers, i will order a multimeter - but i think will look for other speakercables.