a Bessel filter would have the same structure. The value of
the components define what filter type it is.

Bessel: max. flat group delay
Butterworth: max flat frequency response



Cool, didn't know that.

At VLF, the inductances are becoming quite large, requiring a toroid
core for even a simple inductor.

What are the advantages/disadvantages of each type relative to
inductor size requirements?

Maybe I should be looking at a bessel instead of a butterworth.......

GL to all.

T