Last night I hooked my oscilliscope to the outputs of my power follower. There looked like there was an oscillation (>100Khz) on the positive increasing part of the sine-waves.
I decided to increase the cap I have across the base and collector of the NPN transistor used to sense voltage on my CCS. Essentially the same as the Pass CCS using the MPSA18. My CCS is connected to -12v using a IRFP140N.
This cleared the oscillation.
After listening to this though... it seemed that the highs were either A) more detailed or B) more "etched".
Is this the correct way to cure this oscillation? Or would it be better to use a 5uh inductor and a 1 ohm resistor in parallel on the outputs?
Thanks!
p.s. my circuit is a IRFP140N connected to +12 then another IRFP140N used as a CCS to -12. Gain is ~1. DC coupled output.
I decided to increase the cap I have across the base and collector of the NPN transistor used to sense voltage on my CCS. Essentially the same as the Pass CCS using the MPSA18. My CCS is connected to -12v using a IRFP140N.
This cleared the oscillation.
After listening to this though... it seemed that the highs were either A) more detailed or B) more "etched".
Is this the correct way to cure this oscillation? Or would it be better to use a 5uh inductor and a 1 ohm resistor in parallel on the outputs?
Thanks!
p.s. my circuit is a IRFP140N connected to +12 then another IRFP140N used as a CCS to -12. Gain is ~1. DC coupled output.