Andrea CVL-16 "Tough-Dog"

[Penthode]

I am still curious: Why shotgun the electrolytics? I have rarely found bad electrolytics which have not been abused. By abused, I mean applying a full working voltage on a cap which has been dorment for the last four or five decades.

I simply go through the electrolytics one-by-one and rebuild the dielectrics over a couple of weeks. I apply a current limited DC supply and let the capacitors re-build over a few days. After a few days, when the full rated voltage of the capacitor is reached, if the current draw is more than about 500uA or if the capacitor is warm to the touch, then it must be discarded/ or rebuilt. Otherwise, it will probably last another 50/60 years. I have a repaired a lot of older sets over the last 40 years and found only a low percentage to be bad. And the failures were due probably to infant mortality rather than age.

Consider this: I wonder how the newer replacements being stuffed into the cans will hold up fifty years from now? The Sprague and Mallory electrolytics were very well built and are generally should remain okay.

Also I try to steer away from shotgunning is always dangerous and a more methodical approach is safer.