I feel that the welding sounds unusually loud (screaming). What can that be?

Possible cause:

1. It might be that you‘ve changed the type of tinplate (hardness or tinlayer).
2. It might be that you have changed the welding frequency.
3. If it appears a problem and you need help follow:
   1. I have too many „splattering“ in my welder!
   2. How to check welding pressure assembly?