Bias KT88 on Engl Savage 120

[majshumlan]

Hey every one!

Im in a hurry to fix tubes on my Engl Savage 120 head.
Bought 2 matched JJ's KT88 for it.

I used to bias my Marshalls way back but dont never a KT88 or Engl

I have a biasprobe and a good multimeter.

Can anyone give some good advice on wich bias to run the JJ KT88 on?
Or any other good advice,as I said been a loog time ago since last time
and dont wanna destroy anything.

Thanx!

/Nils

[Roe]

what's the plate voltage? how much voltage drop is there across the screen resistors?

[bluesfendermanblues]

Schematic:
According to the schemo, you can measure bias voltages on the primaryside of the Output transformer - 1.1-1.4 DC measured between the centertap an the anodes. http://www.tube-town.de/info/plaene/engl-savage120.pdf

I'm not familiar with this bias setting method, so I would use the traditional method e.g. with a bias meter.

B+
According to this link: http://www.englforum.com/viewtopic.php? ... age#p14789, the Salvage 120 run B+ voltage at 500 VDC. Also the KT88 has a max dissipation of 44 watt.

50%, "Cold" bias = 44ma; (44 watt x 50% => 22watt /500 VDC = 0.044)
70%, "Warm" bias=61ma; (44watt x 70% => 30.8watt/500 VDC= 0.0616)