So combating the rc coupling of the stages can provide stability, this is for the phase splitter and the drivers right? As I remember the common cathode is direct coupled to the phase splitter.
Does less nfb equate to a bigger value in the feedback resistor? This increases gain if I'm not mistaken, or is it vice versa. 🙄
Does less nfb equate to a bigger value in the feedback resistor? This increases gain if I'm not mistaken, or is it vice versa. 🙄
Yes. that is one way of doing it but it is difficult with that many poles, a better way is to use a phase correction network for low freqencies, then you achieve a completely stable circuit and with higher open loop gain = higher degree of feedback down to very low frequencies. Look at the simulations I linked to in my earlier post.
Maybe it should also be mentioned that the original Williamson is not unstable and doesn't oscillate but it has only about 30deg phase margin for low frequencies, this is precisely on the margin for stability according to what Bode wote.
Regards Hans
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