Hello,
I was hesistating to add these questions on the huge JLH 1969 thread, but wasn't too sure how judicious that would be.
Having built my JLH 1969 three years ago with limited knowlege and no measuring tools (things have not evolved that much to be honest ...) I had figured at the time it would be a good idea to put in an analog ammeter to set up the quiescent current and give indications as to possible future faults.
My version is the PNP HOOD 1969 from the usual suspects. I swapped out the input and output caps for better ones. It has an onboard 3055 capacitance multiplier.
- With an 18VAC psu I am measuring +20VDC at the rails. Does this mean that the capacitance multiplier and rectifier are sucking 5V ?
- The ammeter is on the 18VAC lines. I have the current set at 2.2A. I guess this is not the actual quiescent current as the capacitance multiplier must be using some ?
- The meters never really move when the amp is up and running. However, if i tune it up to clipping volumes, the reading sags dramatically. Is this normal ?
Thanks a lot
I was hesistating to add these questions on the huge JLH 1969 thread, but wasn't too sure how judicious that would be.
Having built my JLH 1969 three years ago with limited knowlege and no measuring tools (things have not evolved that much to be honest ...) I had figured at the time it would be a good idea to put in an analog ammeter to set up the quiescent current and give indications as to possible future faults.
My version is the PNP HOOD 1969 from the usual suspects. I swapped out the input and output caps for better ones. It has an onboard 3055 capacitance multiplier.
- With an 18VAC psu I am measuring +20VDC at the rails. Does this mean that the capacitance multiplier and rectifier are sucking 5V ?
- The ammeter is on the 18VAC lines. I have the current set at 2.2A. I guess this is not the actual quiescent current as the capacitance multiplier must be using some ?
- The meters never really move when the amp is up and running. However, if i tune it up to clipping volumes, the reading sags dramatically. Is this normal ?
Thanks a lot
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