I have no (few) delusions. I know that guaranteed that it will be attacked by those who don't understand it; ~30% that real problems will be found by those who do understand it, and 5% that my efforts are of lasting value. All I did can be summarised:
1. My version of "auto-bias" is to move the crossover switching to the drivers. This makes emitter resistors unnecessary, which improves THD, and the bias does not need to be fine tuned. The bias can be fine tuned for even better THD, but then we are back to thermal problems and the need for emitter resistors. It's a great example of the reality for trade-offs.
2. Move the current limit feedback (not included in the original post) ahead of the VAS so that VAS limiting is not required. This is not new and seen in many op-amp circuits, but I did it a bit differently.
3. I did a trick with a diode in the VAS bootstrap that helps to charge the cap quicker at startup. You have to split one of the resistors to keep it from adding distortion. This is related to the:
4. Single supply split by the amp itself. Startup capacitor voltage need to be managed to avoid thumps and pumping. Simulation has to be set to NOT preset cap voltages.
5. The bootstrap divider is not 50/50. This is reduces rail sticking, but it is another trade-off since it compromises the low frequency bootstrap effectiveness.
Those of you have done some design will understand these points and we can have an intelligent discussion?
Dont let the idiots drag you down !
I have been on chat groups for 30 years and this is just part of the course.
Sometimes you just have to put your theories forward and see what happens.
If you get one sensible reply then its worth it.
I had to put forward a software bug that didnt crash on my machine but did on everyone elses ! So put it forward for download and within half an hour the problem was fixed.
For every "twit" there is a decent forumer too.
Please see the earlier threads of OP.
Dear E, S & S, your posts in this thread are too precious to be wasted here. The OP will open another thread at the drop of a post and your posts will be lost.
Dear E, S & S, your posts in this thread are too precious to be wasted here. The OP will open another thread at the drop of a post and your posts will be lost.
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