Yeah I know, this is a pedal forum... But I don't like many of those amp forums. A friend brought around his Magnatone Varsity Reverb amp yesterday because it went bang. I have a look inside and yes, it did indeed go bang! It blew the cathode resistor and bypass cap of the pair of EL84 output tubes. It uses an older Voxish set-up of a 5W 150ohm resistor with a 25µF 50W cap. There is the tell-tale fluffy brown stuff from the cap spread through parts of the amp and a very empty cap can.
What would cause the cathode resistor & cap to blow like that? Apparently before it went the amp was making squealing unpleasant sounds so he switched it off. When he tried it again later it just went bang. Would it be a short in a power tube?
What would cause the cathode resistor & cap to blow like that? Apparently before it went the amp was making squealing unpleasant sounds so he switched it off. When he tried it again later it just went bang. Would it be a short in a power tube?
