Super Weird Bias Issue
Posted: Thu Sep 03, 2020 9:29 am
Hey folks - I recently completed a JTM45 build, and am trying to bias the KT66s. I have this weird bias issue and I'm sure it's some rookie mistake, but I've triple-checked connections, component values, etc. and can't seem to figure it out.
Seems bias current is ~125-135mA no matter what I do. It won't adjust outside these values, stop to stop on the bias pot. I can provide pics if anyone wants to jump in and help sort this out. This is my third build (built a 50w Plexi in 2009 and a 100 MV this year) and haven't really run into any problems I haven't been able to troubleshoot, until now.
I used Classic Tone transformers / choke, and all other parts were sourced from ValveStorm.
Any assistance would be appreciated. Once again, I'm sure it's some stupid-@$$ rookie mistake that I'm not seeing / checking properly.
Seems bias current is ~125-135mA no matter what I do. It won't adjust outside these values, stop to stop on the bias pot. I can provide pics if anyone wants to jump in and help sort this out. This is my third build (built a 50w Plexi in 2009 and a 100 MV this year) and haven't really run into any problems I haven't been able to troubleshoot, until now.
I used Classic Tone transformers / choke, and all other parts were sourced from ValveStorm.
Any assistance would be appreciated. Once again, I'm sure it's some stupid-@$$ rookie mistake that I'm not seeing / checking properly.