Tube biasing settings and preamp tubes

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monkeyking67

monkeyking67

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Hi I need some help here with the power tube settings....on the Diezel site (in tech corner) it states the following settings: EL34's - 60 to 70mA and for KT88's - 80mA , but in there manual that came with my Herbert it state: EL34's - 30 to 35mA and for KT88's - 35 to 50mA....which is it?? can anyone send me in the correct direction please......I would like to install 2 KT 88's and 4 EL34's but not sure which setting to use for the biasing....also can anyone tell me....in the preamp section....can I put any preamp tube in any spot ..V1 tru V6..cause I see I have one 12AT7 in there and was wondering if I can put in a 12AX7???
Thanks....this is a great place to get answers
 
Not sure if this makes a difference but the Herbert is a 2008.....Thanks
 
hey, concerning this:

EL34's - 60 to 70mA and for KT88's - 80mA , but in there manual that came with my Herbert it state: EL34's - 30 to 35mA and for KT88's - 35 to 50mA

the first parameters (60-70mA) are for a PAIR, while 30-35mA is for one single tube!

someone else should respond if the phase inverter (which i think the 12AT7 is) can be replaced with a 12AX7, i dont know about that.
 
by the way....in the same respect....... I bought two pairs of KT77 for the Vh4, where should the bias be at 60-70mA ??
 
Thanks for the info on the power tube Peter,its much appreciated!!
 
Yes, you can use a 12AX7 as a PI. Just make sure it is balanced.

Steve
 
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