bxt403
Well-known member
Hi there,
I need to know the rated/specified (or even actual/measured) capacitances for the original Neumann K67 and K87 capsules to figure out if I keep the bypass capacitor for a clone at 470pF or increase it to upwards of 1000pF.
It's my understanding that low frequency roll-off occurs at a capacitance that's less than 10x the capsule capacitance and that the ideal bypass capacitor value should be >=10x the capsule capacitance.
I've cross-referenced with http://recordinghacks.com/capsules/ to figure out what the exact capacitor value needs to be (as it changes for every different K67/K87 type capsule). The only problem is that (without knowing the capacitance for the original Neumann capsules): I'm uncertain if the 470pF capacitance is actually part of the U87/U87ai characteristic sound (in that having a bit of low frequency roll-off is actually desired and is part of the design).
I need to know the rated/specified (or even actual/measured) capacitances for the original Neumann K67 and K87 capsules to figure out if I keep the bypass capacitor for a clone at 470pF or increase it to upwards of 1000pF.
It's my understanding that low frequency roll-off occurs at a capacitance that's less than 10x the capsule capacitance and that the ideal bypass capacitor value should be >=10x the capsule capacitance.
I've cross-referenced with http://recordinghacks.com/capsules/ to figure out what the exact capacitor value needs to be (as it changes for every different K67/K87 type capsule). The only problem is that (without knowing the capacitance for the original Neumann capsules): I'm uncertain if the 470pF capacitance is actually part of the U87/U87ai characteristic sound (in that having a bit of low frequency roll-off is actually desired and is part of the design).