Question re 4003 pickup inductance

[ikay]

I've measured the DCR and inductance of the stock pickups in my 2019 4003S which come out as:

Neck - DCR 11.2k / inductance 4.0H
Bridge - DCR 11.0k / inductance 4.6H

Measurements were made via the output jack with the pickups wired in circuit. I realise they won't be exactly the same as if measured out of circuit but should be close.

I was surprised that the inductance of the bridge pickup was so much higher than the neck. The wind is pretty much the same as the neck so would the difference just be down to the larger magnet?

The bridge pickup lacks a bit of high end to my ears and doesn't clank like an 80s/90s Ric. I guess this is due to the current higains being somewhat overwound in comparison with earlier versions.

I know that one way to extend the top end would be to de-wind the bridge coil (say down to 9k) which would reduce the inductance and raise the resonant peak.

Would using a smaller bridge magnet (or cutting down the existing one) be another way of reducing the inductance and extending the top end response?

Any comments or suggestions appreciated.

Thanks

[Dirk]

Rather than rewinding pickups, you could use an outboard preamp (or pedal) to compensate.
Ric-O-Sound would give you ability to separate the pickups and treat them accordingly.

I think you're giving too much power to the Ohms effect on the pickups. Also the best way to properly test a pickup is to separate it from the rest of the circuit. Unless you have some way to compare your numbers in the circuit. I don't believe a difference of .2 would be audible. Now if you are testing with the pickups installed then you cannot compare them that way. Well you can but it wouldn't be a fair test.

Good luck on your quest,
Dirk

[iiipopes]

It is subtle, marginal, and may not make a difference, but another thing to try is to swap out 500 kohm pots instead of the factory 330 kohm pots. This lowers the loading to ground and raises the resonant peak of the circuit slightly.

[ikay]

Thanks for the replies. Yes I was toying with the idea of swapping out the tone pots for 500k, that might open it up a bit. I may have a play by disconnecting the caps and adding some resistors to get the pot values up to 500 to see what it sounds like first.

I've also just acquired a State Variable Filter from here - https://www.gitarrenelektronik.de/produ ... ter-detail. This basically allows you to shift the resonant frequency of the pickups from anywhere between 300Hz to 5kHz and vary the level of the resonant peak. Interesting little gizmo. I've configured it as an outboard 'pedal' and will do some experimenting with that. First impressions are quite promising ...

[aceonbass]

These pickup actually measure about 12k out of the box, so your measurements are close. I think unwinding both of these to the vintage spec of 8k will result in a clearer and more..."vintage tone". On the other hand, I've found that starting with Rickenbacker HB1 humbuckers (15k), then coil tapping them at 7.5k is the best of both worlds in my recently acquired, then modded 4003SM CB.

[ikay]

Thanks Dane. Your tappable HB1s now make me want a tappable version of the HiGains, that would be perfect! I'm a bit wary about making an irreversible mod like de-winding but it does seem to come down to that, or swapping out the pickups for something like the Classic Amplification vintage replacements. Bit pricey though.

I know you're very experienced in making replacement wiring looms with 500k/250k pots. How much of a difference does that really make in opening up the sound of the new higains? If you could point me to any sound demos with the 500k/250k mod that would be greatly appreciated.

[ikay]

I've just discovered the Bill Lawrence Q-Filter which is a passive LCR device for modifying (reducing) the inductance of a pickup and opening up the sound/extending the frequency response.

It fits in place of the standard tone cap. The guitar version is tuned to 1.8H and there's also a bass version tuned to 3H which should significantly open up the sound of a 12k HiGain.

Does anyone here have any experience of using this, on a Ric or anything else?

https://www.wildepickups.com/products/filter

[JackTheRipper]

I've just discovered the Bill Lawrence Q-Filter which is a passive LCR device for modifying (reducing) the inductance of a pickup and opening up the sound/extending the frequency response.

It fits in place of the standard tone cap. The guitar version is tuned to 1.8H and there's also a bass version tuned to 3H which should significantly open up the sound of a 12k HiGain.

Does anyone here have any experience of using this, on a Ric or anything else?

https://www.wildepickups.com/products/filter

Bill Lawrence Q-Filter.jpg

That and the State Variable Filter are very Interesting. I don't have experience with either, but would be interested in hearing sound clips of either. Or just seeing what your outboard pedal is like.

I noticed that the Q Filter is "on sale" for the Holidays for $20:

https://www.wildepickups.com/collection ... e-holidays

Wonder if it would fit under the pickguard.

--jack

[ikay]

Hi Jack, no sound clips of the SVF at mo but here are a couple of pics. One knob sets frequency (300Hz to 5kHz) the other sets the Q Factor (magnitude of resonant peak at cut off freq). Jack in and jack out plus mini toggle for On/Bypass. Simple but effective. A useful little box to have on hand to experiment with.

Since starting this thread I've discovered an intermittent problem with the input stage of my practice amp that was dulling the sound of the Ric. Bit wierd, sounds dull(ish) when first switched on but after about 20mins or so it's like a blanket is lifted and the top end comes to life. I tried the Ric with another amp and straight away it had all the bite that was previously missing. So nothing wrong with the stock HiGains at all, in fact they sound fabulous!

[JackTheRipper]

Hi Ian,

Very cool, nice work on the pedal. Thanks for the pics.

--jack

[aceonbass]

Thanks Dane. Your tappable HB1s now make me want a tappable version of the HiGains, that would be perfect! I'm a bit wary about making an irreversible mod like de-winding but it does seem to come down to that, or swapping out the pickups for something like the Classic Amplification vintage replacements. Bit pricey though.

I know you're very experienced in making replacement wiring looms with 500k/250k pots. How much of a difference does that really make in opening up the sound of the new higains? If you could point me to any sound demos with the 500k/250k mod that would be greatly appreciated.

Unlike a volume pot, when a tone pot is wide open, it's at it's maximum rated spec, which in the case of the current 330k pots is actually a tone sucking 275k. The higher rating of 500k, which is what RIC used to use up until several years ago lets through a more open tone with more high end clarity.

[Dirk]

Hey Ian,
first congrats on solving your issue.

Amazing the things we will go to when we are convinced we know what the issue is, and how to fix it.

To me this just proves the need to always keep an open mind.
Your symptoms might be caused by something else and seemingly unrelated in your signal chain.

So I guess the moral of the story is check everything possible in the signal path.
What I'm suggesting is using the scientific method to eliminate things that are NOT causing symptoms.

In any case thanks for the lesson!
Dirk

[Isaac]

Thanks Dane. Your tappable HB1s now make me want a tappable version of the HiGains, that would be perfect! I'm a bit wary about making an irreversible mod like de-winding but it does seem to come down to that, or swapping out the pickups for something like the Classic Amplification vintage replacements. Bit pricey though.

I know you're very experienced in making replacement wiring looms with 500k/250k pots. How much of a difference does that really make in opening up the sound of the new higains? If you could point me to any sound demos with the 500k/250k mod that would be greatly appreciated.

Unlike a volume pot, when a tone pot is wide open, it's at it's maximum rated spec, which in the case of the current 330k pots is actually a tone sucking 275k. The higher rating of 500k, which is what RIC used to use up until several years ago lets through a more open tone with more high end clarity.

I'm a little bit puzzled by this statement, Dane. You say that a tone pot is at its maximum rated spec when wide open, but a volume pot is not? How is this possible? Aren't they the same pots?

[aceonbass]

Tone and volume pots are basically the same, but each are wired into a circuit differently. When a volume is all the way up, it measures zero. When a tone is all the way down, it measures zero or near zero.