02-11-2022, 11:55 PM
Dick, the polypropylene caps will not necessarily reduce ripple more than the same value electrolytics, but they will practically last forever. This is especially important if you restuff the original cans and do not want to ever open them up again in the future.
Modern 8 uF electrolytics are not rated for the amount of ripple current they will see in locations #120 and #121 and will have a relatively short life.
Cap #123 and 123A are a different story. They see relatively low ripple current and electrolytics will last a long time in that circuit location. Their value can be increased within reason to 22 or 33 uF to reduce hum, yet not increase the DC voltage of the power supply.
In any case, adding cap #119 will act as a trap for the 120 hz ripple frequency of the full wave rectifier circuit and reduce the residual hum.
Modern 8 uF electrolytics are not rated for the amount of ripple current they will see in locations #120 and #121 and will have a relatively short life.
Cap #123 and 123A are a different story. They see relatively low ripple current and electrolytics will last a long time in that circuit location. Their value can be increased within reason to 22 or 33 uF to reduce hum, yet not increase the DC voltage of the power supply.
In any case, adding cap #119 will act as a trap for the 120 hz ripple frequency of the full wave rectifier circuit and reduce the residual hum.
