Someone ever tried transplanting a brass baseplate into a Duncan?

[freefrog]

If I can share my 2 cents...

[...]

Mimicing faithfully eddy currents would require a complex network​

[...]

An even better imitation might be obtained from a choke in series with a cap then with a ballast resistor, in parallel with the diodes mentioned above.... <:0)

That's where a 5nF cap might find its place : in series with a resistor of a few kiloOhm, itself in series with a beefy inductor (above 10H, like those used in vintage Gibson Varitone's). The whole to ground in parallel with the pickup. Have botched a 5Spice model of this and it was not far to mimic eddy currents due to brass baseplates. But I'd still add some diode(s) in parallel to approximate the perceived influence of Foucault currents on harmonic distorsion. YMMV.

I've realized that in a comparable way, some theoretical simulations of eddy currents involved RL components in parallel with the pickup, but in series with a "negative" voltage source.

At the end of the day, it's probably simpler to change NS for Brass...

FWIW (2 other cents).

 

[beaubrummels]

3-When I change a BP and find it doesn't fit, I use drilling and cutting tools. I've even cut slices of brass in order to put them under the magnet(s) + coils and to bring these eddy currents mentioned above. It works within the limits evoked in paragraph 2 (but it's not for nothing that Bill Lawrence had designed his pickups with magnetically inert BP's and has even extended this principle to Gibson Tar-Back's).

This makes me wonder if the 'design' of the baseplate could perceptibly or notably alter or compensate a pickup for certain frequencies. E.g. suppose a baseplate had slots (like a mirror image of the top of a FilterTron or Rickenbacker Toaster design), or if the outside portion were brass (kind of the opposite of humbucker covers that expose only the tops of the bobbins but not the sides) with the center portion nickel or plastic to hold things together; or vice-versa, etc.

 

[freefrog]

This makes me wonder if the 'design' of the baseplate could perceptibly or notably alter or compensate a pickup for certain frequencies. E.g. suppose a baseplate had slots (like a mirror image of the top of a FilterTron or Rickenbacker Toaster design), or if the outside portion were brass (kind of the opposite of humbucker covers that expose only the tops of the bobbins but not the sides) with the center portion nickel or plastic to hold things together; or vice-versa, etc.

Totally valid idea IMHO!

In the same vein: as a bobbin able to rise the inductance without too much DCR for his noise sensors coils, Chris Kinman uses a laminated core made of thin metal slices glued together, inspired by those of coils in transformers: IOW, it's like a kind of 3D metal baseplates with myriads of slots in it. The engineer Ken Willmott has also shared the idea to cut parallel slots in metal covers in order to diminish eddy currents. So, slots in a baseplate would also make sense as a way to tame Foucault currents, with the related tonal effects. The only challenge would be to preserve the structural integrity of the whole assembly.

 

[Rex_Rocker]

Alright... thinking this for my last attempt to salvage the Distortion Neck.

Brass baseplate, roughcast A5 magnet.

Thoughts?

 

[Chistopher]

This makes me wonder if the 'design' of the baseplate could perceptibly or notably alter or compensate a pickup for certain frequencies. E.g. suppose a baseplate had slots (like a mirror image of the top of a FilterTron or Rickenbacker Toaster design), or if the outside portion were brass (kind of the opposite of humbucker covers that expose only the tops of the bobbins but not the sides) with the center portion nickel or plastic to hold things together; or vice-versa, etc.

That's essentially the idea behind DiMarzio's Virtual Vintage idea. Shift the inductance of the pickup by adding more "extra" metal.

 

[Clint 55]

Alright... thinking this for my last attempt to salvage the Distortion Neck.

Brass baseplate, roughcast A5 magnet.

Thoughts?

Sounds like a good project. I think if you don't like it as a neck pickup you should use it in the bridge.

 

[Rex_Rocker]

Also, would I need to repot?

At this point, I've removed the cover, swapped the screws, and changed the magnet, and the pickup is starting to get uncomfortably sensitive to tapping on it compared to the unmolested 500T in the bridge.

Repoting might make it a bit warmer-sounding too, right?

 

[Rex_Rocker]

Alright, brass baseplate and roughcast magnet came in.

Just swapped the RC magnet and I don't notice a big difference. Maybe slightly more upper mids? Or maybe not more, but more emphasis on them since maybe the extreme ends of the frequency range were cut? Didn't love it, TBH. But at the same time, it's so subtle that I don't feel like disassembling the pickup to put the polished A5 back in again.

I'll try to replace the baseplate on the weekend, but at this point, I'm not really holding my breath. I realized that as much as I don't love it, I also don't really hate the neck pickup as it is right now. Maybe I just don't like neck pickups overall. Or should I say, passive neck pickups. I like EMG's and Fishman Modern Alnicos just fine.

 

[Clint 55]

RC sux

 

[marcello252]

That's where a 5nF cap might find its place : in series with a resistor of a few kiloOhm

..ehm, isn't this just like turning the tone pot?

 

[freefrog]

..ehm, isn't this just like turning the tone pot?

IME, a tone pot hasn't quite the same effect : eddy currents / Foucault currents introduce distortion and change the dynamics.
It's a really subtle effect. But it's not without reasons IMHO that Bill Lawrence did try to minimize it the most possible in his designs...

 

[marcello252]

IME, a tone pot hasn't quite the same effect : eddy currents / Foucault currents introduce distortion and change the dynamics.
It's a really subtle effect. But it's not without reasons IMHO that Bill Lawrence did try to minimize it the most possible in his designs...

no no, I'm with you about the eddy currents with the baseplate, I was talking about the workaround of putting a RC lowpass filter in parallel with the bobbins

 

[freefrog]

no no, I'm with you about the eddy currents with the baseplate, I was talking about the workaround of putting a RC lowpass filter in parallel with the bobbins

As the LRC stuff evoked was my "idea of the moment" of how to simulate eddy currents thx to external components, it's still not quite the same in my mind than a simple RC filter like a regular tone control.
Now, with a Bill Lawrence Q-filter on the tone pot, it would be another story IHMO: that's almost the circuit that I've described to mimic eddies - and there's some irony in this, since the Q-filter was designed by the man who tried to avoid Foucault currents in his pickups. ;-)

 

[Rex_Rocker]

..ehm, isn't this just like turning the tone pot?

I don't have a tone pot.

 

[Clint 55]

Lopping off a chunk of highs with a hardwired cap is in no way similar to the effects of a brass baseplate. A brass baseplate sweetens up the whole eq, it doesn't lop off a giant chunk of highs. Bonehead comment.

 

[freefrog]

Here are some other bonehead comments, just for the fun...

http://www.billlawrence.com/Pages/Pickupology/External Interference.htm

 

[jeremy]

oh clint, dont you have some day trading to do?

 

[Clint 55]

Lol yes. I should be studying. I've been putting it off.

 

[marcello252]

Here are some other bonehead comments, just for the fun...

http://www.billlawrence.com/Pages/Pickupology/External Interference.htm

I'm interested in getting rid of the static electricity but, uh, ...what is Downey ?

 

[Teleplayer]

The only value cap I tried hardwired that didn't sound like it was chopping off a significant portion of the sound was 100pf.

I have put caps around 100pF into some guitars to tune the pickup resonance. It can sound brighter and more cutting because the added mids have more bite. It was successful with some stock ibanez humbuckers which were initially bland sounding. If I used anything close to 1nF, it sounds like mud which isn't useful to me.