Duelund 12AWG Biwire Amp runs hot

corrrect description for the dueland cable is DCA 12GA

If the only change you have made is installing DIY speaker cables then the problem logically should be with them.

12 AWG should be ok so maybe you have a short circuit. You need to FULLY remove your cables from your system and do an insulation test.

Are the cables true bi-wire? 4 connections at both ends or shotgun 2x4?

To be double sure put the old cables back in to see if the amp still gets hot.

Have you checked the amp's bias settings?

Hello and thank you for your answer.I have remove the DIY cable and check with the old cables - all is fine no overheating.The DIY cable is shutgun 2x4 not true biwire  - at the amp end they are 2 and at the speakers 4,The amp has automatic bias setting.I have the red + 2 together crimped at amp end and one red+ for high at the speakers and one red + for the low at the speakers.Is there a misconception?

I'm thinking one of the runs is shorted. 

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.