So I need to bias my H&K Edition 20w combo amp. It has 2 el84's. This is the only amp I have that needs biasing, so i don't want to spend a ton of money on some sophisticated contraption. I have a cheap multimeter and I'm looking at the Eurotube 9 pin bias probe ($50). I know, "in general", how to check with just the multimeter but I'm not comfortable doing it that way. Is the Eurotube 9 pin probe my best option?