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ubermetaldood
Banned
New member
If replacing with JJ KT77's, does the Fokker require re-bias?
Crunchtime
Active member
Yes, for sure. Just because they are the same brand don't mean a new set won't run a lot hotter or cooler. I suggest getting a Weber Bias Rite. I have one and it works great.
If you need to pay a tech, consider buying 8 matched tubes at a time. Then when you swap tubes next time you should be in safe bias range. The only problem is you will never know if your bias drifts as the tubes break in. That's why it's nice to be able to check it yourself.
If you need to pay a tech, consider buying 8 matched tubes at a time. Then when you swap tubes next time you should be in safe bias range. The only problem is you will never know if your bias drifts as the tubes break in. That's why it's nice to be able to check it yourself.
jc986
Member
If you can order tubes from a supplier that can send you tubes that have the same plate current as the existing tubes then it should not require re-biasing. The stock JJ KT77's in my Fokker have a white label with "60" handwritten on each tube. I would presume this is the plate current those tubes are pulling. If you ordered a matched quartet of tubes that pull a plate current of 60ma then I think you'd be able to get away without re-biasing.
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ubermetaldood
Banned
New member
I have a Bias tester, but was just wondering if Diezel made it any easier with the new model.