just retubed my 350L, wondering what to bias it to?

[foxfire]

this is my first time biasing an amp...i got a quad of JJ kt88's and i've set them to run right around 26 watts static dissipation. i've read that kt88 max at 42 watts and i've read that they max at 27 so i errored on the side of caution at 26 watts. it sounds fine the tubes aren't red plating but i just got this amp and i have no idea how it would sound running hotter?

[mckinnon audio]

  Hi there,here's how I bias amps.You'll need a volt meter and a bias probe,(you can make one or buy one).Measure the plate voltage,Pv and divide that into the maximum power dissipation of the tube,for a KT 88,I use 35 watts,a bit on the conservative side,but safe.The number you'll get is the max.current draw in milliamps,(mA),take this number and multiply by 70% and this will be your bias current.You can run hotter than 70%,but you'll shorten the life of your tubes accordingly.Hope this helps,good luck and be safe !! Mel.

[foxfire]

so if i'm following you correctly, with a wattage of 35 and a plate voltage of 559 (without tubes) i end up with 0.043 or 43ma at 70%. sound right?

[mckinnon audio]

  Hi there,yes the math is correct,good luck,Mel.

[foxfire]

thank you much for the easy/direct process and answer. i went to double check things and let my probe short on pin 2 which blew the big old 5 watter shooting little sparks out towards my face. tons of fun! i replaced it with a 10 watter (the only thing i have on hand) just to make sure i didn't kill anything else which it seems i did not...it wouldn't be so bad if the learning curve wasn't potentially so expensive.