So today I fired up a Gates SA39 we just got in, for the first time. All seems well, tubes start to glow dimly, VU meter starts to move towards zero after a few seconds, so no alerts with me, guessing the power supply starts as expected. I open up the unit, to check some of the voltages. Next I grab my laptop to bring up the schematic, and check my email. In the meantime the smell coming of the unit is noticeable, but I expect it to be some dirt left on the tubes, as it's sort of the familiar smell when starting up an old unit after a while of downtime. Ten minutes, perhaps more, have passed and BOOM!
The 2 in 1 can electrolytic capacitor, the power supply buffer, explodes. Apparently a nice vintage paper in oil cap, as black oily stuff is all over the room, and a nice big pile of smoke fills the air.
The unit is fully original, has never been recapped as far as I can see. The only thing different from the manual is the 5V4 rectifier tube, which has been replaced with a 5R4. But as this tube is almost the same, and has the same pinout, I can't think of a possible way how the voltage may have been inverted. So assuming that this wasn't the case. Could it be that it exploded from old age?
The 2 in 1 can electrolytic capacitor, the power supply buffer, explodes. Apparently a nice vintage paper in oil cap, as black oily stuff is all over the room, and a nice big pile of smoke fills the air.
The unit is fully original, has never been recapped as far as I can see. The only thing different from the manual is the 5V4 rectifier tube, which has been replaced with a 5R4. But as this tube is almost the same, and has the same pinout, I can't think of a possible way how the voltage may have been inverted. So assuming that this wasn't the case. Could it be that it exploded from old age?