Their are a couple demos of this amp running el34s and the amp sounds fantastic but the problem is the tube redplate without modding. It originally runs 6l6 but I wondering what I could do to get it to run el34s without redplating. Thanks.
it is almost definitely a bias issue, the JCA100 has a fixed bias that is internally adjustable and is obviously way too hot for el34s, you need to cool the bias... just don't ask me which way to turn the trim....
The problem from what I understand isn't the trim of ththe bias but more so its range I'm thinking I have to replace the resistor from a 470 to a 1k value but I'm more worried about the power handling of the transformer
Last edited by 95thFallout at Apr 15, 2012,
Using el34s instead of 6l6s would probably increase the power output at most to 120 watts. You lower the screen voltages and reduce the power. The thing I would be concerned about is impedance matching.
Tim the Rocker