The two capacitors (with their parallel small foils caps) are in series which has the following consequences that the total capacitance is less than any one of the series capacitors’ individual capacitances!
https://www.allaboutcircuits.com/textbook/direct-current/chpt-13/series-and-parallel-capacitors/
This turns a 22uf and a 33uf capacitor into a resulting capacitor of 13.2uF!
The result is that you have less filter effect, you need more space on the PCB and have to spend more money on it. Not a good deal.
This kind of series connection of capacitors is done, for example, when the voltage capability of a single capacitor is not sufficient, as in old Fender guitar amplifiers. But that is not the case here, so there are no advantages IMHO, only disadvantages as described above.
Possible solutions would be:
- you use only one capacitor and save space and money with a better filter performance than before
- you continue to use two capacitors as before and connect a resistor in between and get even more filtering because you then have two RC filters after the LM317. Whether this is really necessary is another question, just like C55/C57, whose function is already taken over by C63 in my opinion.
BTW, it is better to make C56 and C62 identical with one capacity, that makes shopping a bit easier. Use 22 or 33uf for both if you want to keep the second cap.
The situation after the rectifier for B+ is similar. At the moment you do not have a smoothing capacitor directly after the rectifier, but two parallel capacitors after the first series resistor R50.
If you would do it like this --> rectifier - C50 - R50 - C54, your filtering would be better than it is now, with the same amount of components.
https://www.electronics-tutorials.ws/diode/diode_6.html
Just my 0,02$
Cheers!
