DIY Pick up testing

[okabass]

Nice advices. Thank you.
I've tried a DI box that has several Megs input, it gives indeed quite bright sound.
I've listened and I have a conclusion that the sound has kind of piezo type not so nice nor warm sizzle. I have now a multicap switch in place of the tone pot. Cap values from 470 pF to 100 nF, and a 16 step switch. I'll listen with different caps. Perhaps I try the screws as a pole pieces.

[rjb]

I've got a troglodyte-level question:

I'm guessing that the original blades are about 16Ga = 1/16" = .0625" ~= 1.6mm thick.
And you are going to try replacing the blade with... perhaps fillister head humbucker screws with 5-40 or M3x0.5 threads, having major diameter of .125" or 3mm?
Question: How thick is the plastic surrounding the blade; can you install the screws without damaging the coil?

Grunt, eh, unga unga
-rb

[Helmholtz]

Normal P Bass: 250 kΩ vol pot and tone. Very clever simple idea. Must try.

Well, as you have a tone control, do you use it ? The simplest way to reduce resonance Q is to back the tone control a bit. Does this cure your problem?

Sorry, just saw that Antigua recommended the same.

[okabass]

I've got a troglodyte-level question:

I'm guessing that the original blades are about 16Ga = 1/16" = .0625" ~= 1.6mm thick.
And you are going to try replacing the blade with... perhaps fillister head humbucker screws with 5-40 or M3x0.5 threads, having major diameter of .125" or 3mm?
Question: How thick is the plastic surrounding the blade; can you install the screws without damaging the coil?

Grunt, eh, unga unga
-rb

I have a watchmakers education, I can work a bit with materials. I think I can joint the screw and the 1,6 mm blade.
Here's a watch I've made.
http://okabass.suntuubi.com/datafile...s/HPIM1265.JPG
http://okabass.suntuubi.com/datafile...s/HPIM1262.JPG

[okabass]

Hemholtz:
Yes I tried tone control. I have now "multicap switch" instead of normal tone. I found it better than normal tone (250kΩ + 47 nF or 100 nF).
Listening sounds are strange, now it sounds quite good with a fet bass preamp.

[okabass]

250k is about as low as you can reasonably go with off the shelf parts, so an alternative to forcing a lower Q would be a 500k trim pot, so that you can dial in some ideal amount of additional parallel resistance. Turning down the tone pot also lowers the Q, so this mod is roughly the same as forcing "8" or "9" to be the maximum tone setting, depeding on the value of resistance.

If you wanted to see what was happening for certain, it's possible to see the resonant Q with a bode plotting oscilloscope, such as the Velleman PCSU200, or you can even create a model with LTSpice, which is free, plug in the values of the pickup and simulate different loads. That latter wouldn't model the eddy currents of different screws, but it would reveal the change you get with, say 250k versus 500k pots. If you've never done either of these things, there a learning curve involved, but it's worth knowing that trial and error isn't the only option available.

Thanks. Must try the Spice.

[Helmholtz]

Hemholtz:
Yes I tried tone control. I have now "multicap switch" instead of normal tone. I found it better than normal tone (250kΩ + 47 nF or 100 nF).
Listening sounds are strange, now it sounds quite good with a fet bass preamp.

Do you use your DIY SVT clone?
Have you seen this: https://www.thomann.de/gb/neutrik_np...d_rel_269841_0
The plug incorporates 3 switchable capacitors. Haven't tried it myself. There is a cheaper version wihout the "silent" function.

[okabass]

Do you use your DIY SVT clone?
Have you seen this: https://www.thomann.de/gb/neutrik_np...d_rel_269841_0
The plug incorporates 3 switchable capacitors. Haven't tried it myself. There is a cheaper version wihout the "silent" function.

Yes I use. It has worked 12 years without problems, like it a lot.
I have seen, not tried. Good idea, if you like the cap values.
Ps. I recommended non-silent version. It is clever idea, but i have had several (3-4) Silent Plugs that have stopped working (always on).
I have made some multicap circuits in an effectbox. Some guitarist like it on Stratocaster to tame the brightness without changing the mids. Give it try it sounds quite nice.
https://i.pinimg.com/236x/b7/c4/7e/b...ic-guitars.jpg

[Antigua]

I just installed a multi-cap control in a Strat, with values ranging from 1nF to 10nF, and they really do render PAF to P-90 like tones. It's very similar to the results you'd get with a single coil sized humbucker, and from all I've learned about how pickups operate, I see very little reason why their should be a noticeable difference between a single coil sized humbucker, and a single coil with a cap. Aside from noise, the other minor issue is Q factor, in that a Fender pickup has a higher Q factor than a PAF or a P-90, which lends itself to a stuffy nose nasal tone, though this is easily remedied by a either rolling back on the tone control, or installing a permanent resistor, to enforce a particular damping factor. There's apparently an aversion on the part of pickup makers to involve caps and resistors in a passive pickup, because there's not much precedent for doing it. The only instance I know of where it has happened is with the Invader pickup, which has a series cap that forces a reduction is bass response.

Adding a fixed capacitance is somewhat dubious in that you can accomplish similar results with added inductance, and because the final outcome is subject to cable capacitance as well, but I think a fixed resistance makes sense, for the fact that 250k or 500k pots are standard in models of guitar for which a pickup is intended to fit, so as a pickup designer, you might not know what the final capacitance will be in the customer's rig, but you have a good idea of what the overall damping factor will be.

[Joe Gwinn]

Now I've been listening more, the high end could be more warm (add a little cap?). It has kind of sizzle. In what direction laminated blades will go? Part of the '51 PU's sound I like is kind of brutal attack because of single ca. 5mm magnet pole per string. I may try little screwheads as poles.

The thinner blades allow more high frequency to come through.

Ps. Got a idea to use screws as pole pieces, to make it less sizzly. I tried with a 7ender bass PU screw and magnet bar only. I got ca. 300 Gs at the screw head. What do you think: is that too little.
I checked some Gauss values, it is not very far from P-90 (Alnico II). Or PAF (Alnico II or V).

No idea. What does it sound like?

[okabass]

The thinner blades allow more high frequency to come through.

No idea. What does it sound like?

Ok Thanks. Have enough HF.
Haven't tried the screws yet, only make one screw connected the blade.

[Helmholtz]

Yes I use. It has worked 12 years without problems, like it a lot.

The reason I asked is that I wonder why you use an additional FET preamp. Do you need the extra gain for some distortion?

I have made some multicap circuits in an effectbox. Some guitarist like it on Stratocaster to tame the brightness without changing the mids. Give it try it sounds quite nice.
https://i.pinimg.com/236x/b7/c4/7e/b...ic-guitars.jpg

Inspired by Lemme's first book I have done things like that for my shop customers in the early 80s.
Personally I have no desire to radically change the sound character of my strats and lps. But I prefer a total capacitive load (including cable capacitance) of around 1200pF.

[okabass]

FET pre is that ROG Ginger. I made it in an effect box, and use it when not possible to take the SVT-clone. I like it more than for example those Sansamps. Nice distortion too. It surprised me that it works ok at 9 volts. I've used it at 9-24 volts.
Ginger

Yes, the using the c.load is a sophisticated way to fine tune guitars or basses sound. Normal tone is good "quick and dirty" on live. But like recording its nice to have multicap in your arsenal.