Arc protection AL572
Because of poor tube manufacturing or poor tube processing, 572B tubes have an abnormally
1.) Remove the cover, tubes, and turn the amplifier upside down.
2.) Remove the six screws that hold the service plate under the tubes, and
3.) Remove the six screws that hold the tube “chassis plate” to the cabinet
4.) Remove the 51 ohm resistors and .01uF capacitors at each grid pin, and
5.) Install two 150-volt to 170-volt gas voltage protectors.
Hint on soldering parts or connections to “no hole” PC boards
This is an AL80B socket, but the same principle applies.
1.) Pre-tin component lead with a generous amount of fresh solder
2.) The component should have a slight excess of clean fresh solder on the
3.) You also want to pre-tin the area of the board you want to solder to, or
4.) Notice the slight excess of solder near the holes where the part will
5.) This is a sweat-soldered AL80B protection system. The connections are