Hi gang, I'm back. I am just about ready to close up the box on a PL700 S2 that I did a full WOPL on including a WA protection circuit. All voltage and grounding tests have been performed, and the bias set.
I just finished a full powerup (outside of the Dim bulb tester), and everything checks out.
I have been faithfully attaching draining resistors to the filter caps between every test, and installation of the driver and output transistors.
However, out of curiosity, I began checking the rate of voltage drain of the big filter capacitors. To my surprise, as I lowered the voltage of the variac, (without the resistors attached) the capacitors would discharge pretty much to zero as fast as I could take the variac down.
With the final test, no variac and no dim bulb, when I shut the amp down, the filter caps dropped again, very quickly. I noticed when I performed tests on the backplane operation before mounting the transistors, the caps would retain a very high level of charge for quite some time. It was after I added the first row of drivers that I noticed the quick rate of discharge.
Before I take this to the next tests (meter balance and audio) I thought I would ask the brilliant minds here if this is normal?
The short version of the question: Is it normal for the filter caps to very quickly discharge after power down?
BTW thanks to Joe at White Oak for giving me a tip regarding the embarrassing results of a test i ran, and to Professor Mark Comer for the entertainment and great how to videos!
I just finished a full powerup (outside of the Dim bulb tester), and everything checks out.
I have been faithfully attaching draining resistors to the filter caps between every test, and installation of the driver and output transistors.
However, out of curiosity, I began checking the rate of voltage drain of the big filter capacitors. To my surprise, as I lowered the voltage of the variac, (without the resistors attached) the capacitors would discharge pretty much to zero as fast as I could take the variac down.
With the final test, no variac and no dim bulb, when I shut the amp down, the filter caps dropped again, very quickly. I noticed when I performed tests on the backplane operation before mounting the transistors, the caps would retain a very high level of charge for quite some time. It was after I added the first row of drivers that I noticed the quick rate of discharge.
Before I take this to the next tests (meter balance and audio) I thought I would ask the brilliant minds here if this is normal?
The short version of the question: Is it normal for the filter caps to very quickly discharge after power down?
BTW thanks to Joe at White Oak for giving me a tip regarding the embarrassing results of a test i ran, and to Professor Mark Comer for the entertainment and great how to videos!
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