ARC CA-50 tube changing

Well that stuff runs at high voltage i.e. 420Vdc on the plates and screens. You can't just stick your hands in there. You need the proper probes to measure bias voltage drops. Make one wrong move and poof, the outcome will not be pretty. I would suggest to let an authorized ARC tech. take care of that for you. If the boards weren't vertical, you probably could have done it yourself

I had a CA-50 and bias setting was not too hard, just remember the high voltages involved and be careful!

Problem solved! I learned that my local second-hand audio dealer has lots of experience changing and biasing the ARC tubes. Echo Audio in Portland.

Thanks guys, i don't want to risk getting fried...