I've looked at the Damage class chart in 5ed and the only place where 1 pip is mentioned in 5th ed (at least that I've found) is in the first line of that table.
DC Killing Normal 1 1 pip 1d6 2 1/2d6 2d6
Hence, based on that, I'm going to rule that 1 pip = +1 NOT 1 DC since 1 DC refers to any one step on the table and 1 pip only refers to the first step (+1). The other reason why I'm making this ruling is because other steps may add more than +1 to the killing damage and your situation clearly states that no more than 1 pip can be added.
Sometimes HERO makes me want to feed the book to its creators.
no subject
Date: 2007-06-16 02:55 pm (UTC)DC Killing Normal
1 1 pip 1d6
2 1/2d6 2d6
Hence, based on that, I'm going to rule that 1 pip = +1 NOT 1 DC since 1 DC refers to any one step on the table and 1 pip only refers to the first step (+1). The other reason why I'm making this ruling is because other steps may add more than +1 to the killing damage and your situation clearly states that no more than 1 pip can be added.
Sometimes HERO makes me want to feed the book to its creators.