Close up showing sectioned bobbin/windings.
Parallel = 1:20
Series = 1:10
Inductance of primary winding:
Parallel = 31 mH @ 1 kHz, 141 mH @ 120 Hz.
Series = 100 mH @ 1 kHz, 544 mH @ 120 Hz.
Inductance of secondary winding:
Each = 2 H @ 1 kHz, n/a @ 120 Hz.
Inter-winding capacitance between input and output windings = 208.3
Input impedance in circuit when powered:
Parallel = 165 Ω.
Series = 667 Ω.
Termination Resistor (see schematic) = 120 KΩ
(Adjust to obtain flat frequency response and match source drive impedance.)
A M6/Mumetal 50/50% core version is an option.
Note however that Mumetal saturates at a lower level than M6 (40%?) so a 100%
Mumetal core is not always advised.
The use with Mumetal laminations does make a measurable improvement, reducing
mid-band distortion however the lowest end for LF distortion is not quite as