Hi guys,
I rebuilt an old amp which was originally full complementary in quasi complementary.I used 2 pairs of c5200.
I already tested the amp with +/-4v(funny,but the sound was clear before clipping).I connected it to a +/-30vdc power supply with a 60W bulb in series with the primary winding.I set the bias pot to max R,but when i measured the voltage drop across the emittes R's(0.22R),i got 35mv.Isn't this figure a little too high for class AB?How do i reduce the idling current as am intending to use +/-50 volts?
Regards.
I rebuilt an old amp which was originally full complementary in quasi complementary.I used 2 pairs of c5200.
I already tested the amp with +/-4v(funny,but the sound was clear before clipping).I connected it to a +/-30vdc power supply with a 60W bulb in series with the primary winding.I set the bias pot to max R,but when i measured the voltage drop across the emittes R's(0.22R),i got 35mv.Isn't this figure a little too high for class AB?How do i reduce the idling current as am intending to use +/-50 volts?
Regards.
Can you take a screenshot of the VAS and Vbe mulitplier so I can see how the pot works ?
If the VAS uses a constant current source then the power supply shouldnt matter much as the current should stay the same through the Vbe multiplier.
On my quasi design I could get the bias voltage down to zero. Could be your design has got extra resistors in to limit the bias range.
If the VAS uses a constant current source then the power supply shouldnt matter much as the current should stay the same through the Vbe multiplier.
On my quasi design I could get the bias voltage down to zero. Could be your design has got extra resistors in to limit the bias range.
Not the case
This doesn't seem to be the case,with +/-50v,supply am measuring 43mv.The bulb is still in place.I just measured the rail voltages and they are just at 16.9v.
Regards.
This doesn't seem to be the case,with +/-50v,supply am measuring 43mv.The bulb is still in place.I just measured the rail voltages and they are just at 16.9v.
Regards.
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