Need Bias Values For A JTM60!!! EL34's!!!

Discussion in 'Marshall Amps' started by MartyStrat54, Mar 22, 2009.

  1. MartyStrat54

    MartyStrat54 Well-Known Member

    Feb 21, 2009
    Likes Received:
    Hello: Marty here. I'm trying to help out cudamax2343. He's got a JTM60 head and he is wanting to bias a set of tubes in the head. Is the bias the same as other 600 series heads? My TSL602 is biased at 80mV (40mV each tube).

    Does any of you other techs know what the bias value is for this amp? I can't find it anywhere. Not even on Dr. Tube.

    Also, it appears that unlike my TSL 602, there is only one neutral test point and one hot test point, instead of a hot-neutral-hot found on my 602. Is that correct? I've never worked on a JTM60 head and I am just trying to get cuda going down the road...safely. I don't want him burning any tubes.

    Help us if you can.


Share This Page