Marshall JCM 800 2203 Guitar Amp - Tube Swap and Re-Biasing

Chris from Cornerstone joins us again for this Marshall re-biasing video. This is an all original JCM 800 - 2203 that is receiving new tubes all around. Of course, a quick inspection is in order. Measurements of the electrolytic caps show that most of the caps are good, one of the filter caps are about ready to go. As I make incremental adjustments to the bias as the tubes cook, The question is, are the tubes really balanced as the box from mesa advertises.. I'd think not. As a matter of fact, the tube deviation is 6 miliamps from all 4. Good thing I was biasing for the highest current flowing tube. Robotube is fired...