Vintage bridge capacitor pickup bypass

Vintage, Modern, V & C series, Fretless, Signature & Special Editions

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Vintage bridge capacitor pickup bypass

Postby (TTA) » Sun Oct 10, 2021 5:05 pm

Forgive me as my 4001 has the bridge capacitor bypassed. And i dont yet have a modern ric with the toggle.

When the capacitor is engaged (vintage setting), what frequencies are bypassed in the bridge pickup? (Ex: 500hz and below)

The neck and bridge pickup are in parallel… and they display phase cancellation when both full volume. What happens to this phase cancellation when the vintage setting is on? I wonder if you get less midrange scoop than one might expect (both pickups on full).

Just curious. I should be able ro test it myself in a few weeks.

Also… any compatibility issues retrofitting a 4001 and 90’s 4003 with the new toggle switch circuit?
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Re: Vintage bridge capacitor pickup bypass

Postby (aceonbass) » Mon Oct 11, 2021 7:59 am

There is no phase cancellation when the vintage tone circuit is engaged.
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Re: Vintage bridge capacitor pickup bypass

Postby (iiipopes) » Fri Oct 15, 2021 9:41 pm

Assuming the pickups are wound and wired correctly. What you are hearing when the inline capacitor to the bridge pickup is bypassed is not really phase cancellation. Sometime when you want to experiment, swap the two leads of one of the pickups and dime the controls, and then you will hear what true phase reversal or out of phase tone is: a weak, hollow, nasal tone.

What you are hearing is a bit of phasing from what we call comb filtering from the string being sampled at two disparate points, as some of the overtones are out of phase due to the physical separation of the pickups. But not everything, or you would lose your fundamental as you do when one pickup is wired backwards.

The other thing you are hearing with the inline capacitor out of the circuit is impedance drop. With both pickups wide open, and they are effectively wired in parallel, the impedance of the output is approximately half of that of one pickup alone. Our ears perceive impedance drop as a drop in the mids. That is exacerbated by a Rick bass having a maple body, which has a natural dip in response in the upper bass/lower mids. That's why when you roll off one of the pickup volumes to about 8 that everything sounds full on again: you have less effective impedance drop with the introduction of variable resistance to the circuit.

As aceonbass observes, when you have the capacitor in line, there is no true phase cancellation. Having the capacitor in the circuit lowers the volume of the bridge pickup a little bit, cuts the bass output of the bridge pickup, and changes the phase of the signal above the hinge frequency of the capacitor 90 degress, which further reduces the comb filtering problem and reduces the impedance drop when both pickups are dimed.

And that is what really happens between having the inline capacitor to the bridge pickup in or out of the circuit.
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