As long as you use the same kindda tube ie. 6l6 and the bias switch is set to 6l6 when using 6l6's
you put the power tubes in the right place
you use 12ax7's or equivelant in the preamp section
In a dual rec if you are lookin at it from behind you will see 4 big tubes with writting on them that either says 6l6 or el34-these are the power tubes
The ones next to them are your rectifier tubes and will say 5u4 on them
Behind the power tubes you will find a row of 5 smaller tubes-these are your preamp tubes(probably where your fault is lying),these may have metal sleeves around them,hold onto the sleeves and twist until they pop off,then gently pull out the tubes-MAKE SURE THE AMP IS OFF BEFORE REMOVING ANY TUBES
On the Back left hand side of the inner headshell of the amp you will see a small diagram of the inside of the amp,it will tell you that the tube closer to that diagram is called v1,then moving further away v2,v3,v4,v5
Replce the preamp tubes,put your power tubes back in and power up see if it is working,if not replace your power amp tubes check that,if not I would change the rectification to diode then see if that works,If it does you have faulty rectifier tubes,this is unlikely but if you use this system you should find your fault
You cant really go wrong with changing tubes as long as you just remember how they were in originally,tubes usually have a central guide pin that will keep you right,just align the pin with the tube socket and your away
The tricky part is the preamp section because you cant really see it that well
I would also make sure you are using tested tubes and that they are basically all at the same Bias,basically use Mesa tubes and your playing it safe
If an 18 year old can do it anyone can
