mcandmar
New member
In general the more capacitance the smaller the ripple, i.e. the smoother the DC voltage will be and the quieter the power supply. At what level you reach the point of diminishing returns i don't know, but i suspect Paul calculated it from a combination of testing, experience, and utilizing the parts bottlehead already stocked.
Using a choke to filter the supply is far more effective than bulk capacitance so capacitor size can be reduced when using a choke with little to no negative side effects. I tried to simulate the Crack circuit with the information i had at hand and estimated around 1.5mv ripple with the stock configuration of three 220uf caps, with a C-7X choke i kept lowering the capacitance of the caps until i got back to ~1.4mv ripple and was using 220uf, 100uf, and 22uf. The advantage of downsizing the caps would be the availability, lower cost, and physical smaller size of Poly film caps to replace the electrolytic. But if you can put 220uf poly films in there go for it.
Using a choke to filter the supply is far more effective than bulk capacitance so capacitor size can be reduced when using a choke with little to no negative side effects. I tried to simulate the Crack circuit with the information i had at hand and estimated around 1.5mv ripple with the stock configuration of three 220uf caps, with a C-7X choke i kept lowering the capacitance of the caps until i got back to ~1.4mv ripple and was using 220uf, 100uf, and 22uf. The advantage of downsizing the caps would be the availability, lower cost, and physical smaller size of Poly film caps to replace the electrolytic. But if you can put 220uf poly films in there go for it.
