scombridae
New Member
Hello everyone,
I recently recapped my Fisher 500c with the metalbone kit. I put it on the Variac and fired it up on the first try. I was amazed it went so effortlessly. My worst fears became reality when after 45min of playing at moderate levels brought snapping electrical smoking nastiness to my life. Let me first say I am not super knowledgeable but I can make up for it in effort and a eagerness to learn. Looks like this amp is going to be a great opportunity.
Long story short V10 output got super hot and smoked. Upon further inspection, terminals 2 and 3 got hot enough to melt the insulation from the wires. I also noticed two resistors I believe to be R120 and R85 on the schematic fried. Additionally, the unit had a 4amp fuse instead of the 3.2amp recommended.
I have since replaced with the correct fuse, cleaned up the wiring and replaced the burnt resistors. I then slowly powered up the amp again but the two resistors started smoking again at 80-100v.
Do I have a bad transformer/s? Do I have a short? Where should start to look and test? How do I test for a bad transformer? How do I test to see if my tubes are still good?
Thanks in advance for any help
I recently recapped my Fisher 500c with the metalbone kit. I put it on the Variac and fired it up on the first try. I was amazed it went so effortlessly. My worst fears became reality when after 45min of playing at moderate levels brought snapping electrical smoking nastiness to my life. Let me first say I am not super knowledgeable but I can make up for it in effort and a eagerness to learn. Looks like this amp is going to be a great opportunity.
Long story short V10 output got super hot and smoked. Upon further inspection, terminals 2 and 3 got hot enough to melt the insulation from the wires. I also noticed two resistors I believe to be R120 and R85 on the schematic fried. Additionally, the unit had a 4amp fuse instead of the 3.2amp recommended.
I have since replaced with the correct fuse, cleaned up the wiring and replaced the burnt resistors. I then slowly powered up the amp again but the two resistors started smoking again at 80-100v.
Do I have a bad transformer/s? Do I have a short? Where should start to look and test? How do I test for a bad transformer? How do I test to see if my tubes are still good?
Thanks in advance for any help