I had this problem with Sprague atom capacitors the blue ones not made in the USA.
After 10-20 hours of burn in time tic, tic, tic, flame on, sparks and smoke.
It drove me crazy checked grounds more times than I could count.
I switched the power supply filter capacitors to Mallory TC series
Problem solved. It also traced back to v-1. I found out that the Mallory’s are pre formed at the factory and the new Sprague atom’s are not. I was also told that Sprague owns Mallory now
Good bye quality US made capacitors.
Temperature. ripple current, overvoltage (ripple voltage plus operating voltage) were not a factor. The tic sound was probably internal arcing and breakdown, as mentioned. Reforming is always a good idea, no matter who the manufacturer is and if you don't own a variac, the series light bulb trick is better than nothing when initially turning on a new build.
Deric wrote:A long-shot and from your description most likely not related but... If you touch the standby switch does it stop?? I built an SLO clone that had an intermittent ticking. Wasn't always there but when it was it was very regular - about every second. Touching the standby switch made it disappear. Turns out it's a common problem with SLO's. The Soldano factory fix is to remove the powder coat from the inside of the chassis where the standby switch mounts. Worked on my clone...
Good luck!
Well Deric, maybe you're long shot is really it. The standby switch housing was not grounded well, I could make the amp tick by touching it. Charge was building up on the switch and discharging through me? I ground off the extra powder coat and made a better contact. I hope I'm not speaking too soon, but it seems to have solved the problem. Thanks for the suggestion, if you are ever in San Jose CA I owe you a beer!!!
Someone want to take a shot at explaining the phenomenon at work here? Where is the charge buildup on the switch housing coming from? Is this a static buildup caused by the current flowing through the switch?
