So by tube substitution you mean replacing the tubes I bought brand new with other ones or switching their positions? Since I have already spent $35 on two new tubes I would hate to have to buy another set. What would I have to do if the problem lies with the power supply besides buying another power supply?
Thanks for your help The EH Man!
It happens all through my jam session. I know power tubes need time to warm up. Do regular tubes require some warm up time too?
Thanks