• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Magnets & Copper Wire: A Pickup Building Thread

#181
Bruce Johnson said:
Yes, microphonics is a bigger problem when you get into hi-fi pickups like this. Like Jon said, as you build a pickup to detect really fine movements of the string, then it also can detect really fine movement of itself in relation to the string. This can be internal movement of the coils in relation to the magnetic field, and it can also be movement of the whole pickup in relation to the bass. Its sensitivity is increased overall.

Is it locked down tight in your test bass rig? What was good enough for other pickups may not be good enough for this definition-monster.
Click to expand...

I’m going to try two things: I’m going to pot the coil/pole assemblies together and try placing some foam tape underneath.

@MPU suggested trying ceramic magnets instead of neodymium - I’m trying to resist doing that, but I know in my heart of hearts it will probably sound better. I really don’t want to cut any C8 stock down - toxic magnet dust everywhere...
 
#183
Bruce Johnson said:
??? Foam tape? Where? That's the last thing you want in trying to stop microphonics. Everything needs to be held rigidly together.
Click to expand...

Sorry, I meant to type “foam”. I need to get some more foam tape.

I was going to put a piece of foam between the baseplate and the body. Right now the baseplate is resting directly on the body.

F0F4F291-710C-4C42-8A82-9B255D38C39F.jpeg
 
  • Like
Reactions: Beej
#184
Freekmagnet said:
I was going to put a piece of foam between the baseplate and the body. Right now the baseplate is resting directly on the body.
Click to expand...

No, No! That's the opposite of what you want to do. That will make the microphonics much worse. The whole pickup needs to be mounted rigidly to the body. If the pickup can flex and move in relation to the body, then it will create sound whenever you bump the body.
 
  • Like
Reactions: NKBassman and Freekmagnet
#185
Bruce Johnson said:
No, No! That's the opposite of what you want to do. That will make the microphonics much worse. The whole pickup needs to be mounted rigidly to the body. If the pickup can flex and move in relation to the body, then it will create sound whenever you bump the body.
Click to expand...

You don’t think the pickup is moving in relation to the body now? As is, it makes a lot of noise if I’m playing and I change my seating position. I suppose I could use longer screws and really, really bolt it down to the wood.
 
#186
Freekmagnet said:
You don’t think the pickup is moving in relation to the body now? As is, it makes a lot of noise if I’m playing and I change my seating position. I suppose I could use longer screws and really, really bolt it down to the wood.
Click to expand...

It may be, and that may be the biggest source of the microphonics that you have. The whole pickup needs to be fastened down solidly to the body. You should not be able to cause any movement when you push on it. Any movement between the pickup and the body creates a signal, because the pickup blades are moving in relation to the strings.
 
#187
Bruce Johnson said:
It may be, and that may be the biggest source of the microphonics that you have. The whole pickup needs to be fastened down solidly to the body. You should not be able to cause any movement when you push on it. Any movement between the pickup and the body creates a signal, because the pickup blades are moving in relation to the strings.
Click to expand...

OK. I’ll take a look at that tonight.
 
#191
Freekmagnet said:
No, the coils are not glued in. I think I might try to “pot” them with some CPES tonight.
Click to expand...

Oh okay, well, there's your microphonics. If the coils can move at all in relation to the magnet structure, they'll generate signal at the slightest bump. If you don't want to glue them yet, at least stick them down with double-sided tape. Not foam tape!
 
  • Like
Reactions: Freekmagnet and mapleglo
#192
Now that I’ve pretty much got the body and neck built out, I’m back to pickup making.

img_6593.jpg


My first wind was OK, but it was a little mid-heavy and the bass was really murky and dark. I was also getting what I believe were microphonic vibrations that I couldn’t pinpoint.

I took this new wind count down about 20% and while I was at it, I made the bobbins about 1/32” narrower. I also omitted the steel slugs I had placed in the bobbin cores. I figured that the slugs were overkill and if anything, they were likely to be the source of my microphonics.

The new wind sounds really good. I really like it. The bass, middle and treble are nicely balanced. It’s bright, but not too bright. The upper highs are nicely extended without sounding clangy.

I still don’t think it’s realistic to have bridge pickup serve as both a bridge and a rhythm pickup without the assistance of a preamp. There’s just not enough low-end happening down there. I do think that this one comes pretty close - it has plenty of output and almost enough lows, but not quite.

I’m going to sit on this one for a few days and maybe see if I can knock out a quick 2-band pre and see what happens.

The next step is two-fold. I have to make an attachment that allows my winder to wind these small coils more accurately. I also have to figure out how I’m going to build this monster.

The hard part is going to be wire joints. Maybe I’ll make half of the bobbin a cast piece with the wire terminals poking out. The other half will be thin cardboard. The wire terminals could then be joined to a little circuit board. Something like that. Then just dunk the whole thing in epoxy. I’ll have to think about it.

@MPU: I did as you suggested and built a ceramic version. I also believed that ceramic magnets would sound better in this pickup. However, the ceramic version didn’t have as much output and didn’t put out much low end. I went back to the neodymium magnets.
 
Last edited:
  • Like
Reactions: Beej, Novarocker, Bruce Johnson and 1 other person
#193
I stopped by Bruce’s place on an unrelated errand last week. We got to talking about bobbins and threw some ideas around. As it so happened, we had some similar bobbin brainstorms. In the end, it's all boils down to execution.

Basically, the idea was to use one cast polyurethane side of the bobbin to house the wire terminals. The other half would be made of paper. Eventually, I’ll seal the wire side with another piece of paper before assembly. So with this concept, I made my first bobbin prototype:

img_6613.jpg


This piece is really small. It measures about .6875" tall and a little less than .875" wide. It's smaller than a nickel. It's .25" thick. The polyurethane base that holds the wires is .09" thick. I cut the grooves in the base with a small file.

Making the master was really easy. For the flatwork, I cut a shape out of .09" aluminum and drilled a 5/16" hole in the middle of it. For the central core, I stuck a 5/16" wide aluminum spacer I bought at the local hardware store. Since the bobbins are offset, I need a pair of mirror image bobbins. To make the second mold, I flipped the flatwork over and re-inserted the spacer. Here's a picture of one of my first attempts.

img_6602.jpg


This bobbin is a crucial step on a long and complicated road. Space is tight. There's a lot of parts to make and wire joints that could fail at any time during assembly of the pickup.

I'm really excited about this pickup design. I still have my last prototype installed in the test bass. I also built a little preamp based on the 3-band StingRay pre. I basically removed the middle band and changed the treble control to cut off at about 1000Hz - basically the treble cuts and boosts both the mids and the highs. Overall it sounds great. The pickup sounds as thick as a brick, but the narrow sidewinder coils really extend in to the upper range. I tweaked the input cap on the preamp to allow more of those highs in. I'm boosting the bass a little bit - if the center of the pot is zero, I have it at dialed in at about 1.5. The treble knob hovers at around .5 to 1. If this pickup were in the P-bass position, it probably wouldn't need a preamp at all. I think the only thing that matches my excitement is my desire to get it up and running.

I still haven't modified the winder. I'm waiting for some parts in the mail.
 
Last edited:
  • Like
Reactions: wraub, Tom McClintock, Novarocker and 6 others
#195
Beej said:
I can't wait for the day you post up "hey, I have one of these for sale, anyone interested?" :D

I would throw down over 300 for one of those toaster thingys like is in Sirena in a New York second...this one is even cooler :thumbsup:
Click to expand...

I have a few of those toasters in production right now, so if you want one, PM me. They’ve been on the back burner due to this current R&D project - I’m not really trying to a business at this time, so with family, day job and band constraints, the fun stuff takes priority.
 
  • Like
Reactions: wraub, Novarocker and Beej
#196
I don't have too much to report this week. Basically, pickup making is all about making lots of small parts. So, I've been making lots of small parts.

img_6625.jpg


Clockwise from top-left: A pile of cast polyurethane bobbin halves for the Funktronic Exotica pickup; six epoxy-encapsulated coils for the Funktronic Bass Sidewinder pickups; a pile of ears for the Funktronic Bass Sidewinder pickups; some 430 stainless steel blade poles for the Funktronic Bass Sidewinder pickups.

I set out earlier in the week to make parts for the new Exotic pickup and make 3 Bass Sidewinders that I'm hoping to unload. After starting by making molds for the Exotica bobbin halves, I cast a whole bunch of them over the last couple of days with the Smooth-On bright white polyurethane casting resin. I like the Smooth-On stuff - at least I like it more than I like the black ModelMaster stuff I've been using. I just get better castings out of it. In any case, the shelf life once it's opened is really short, so I'm trying to use up as much as I can. Bruce suggested using the aluminum base plate he made for me a while back as a master. Hopefully, I can get to making a mold from it later in the week and use even more of the Smooth-On before it starts going bad. I'll have to remove the pickup from the test bass, dis-assemble the pickup and cast the part. With any luck, the coils and wiring will be intact enough to re-assemble and re-install it into the bass.

Speaking of the Exotica, I've been playing it quite a bit in the test bass. The jury is still out as to weather or not it could work on it's own as a passive bridge pickup; I think it puts out a respectable amount of lows and mids for its size - it just doesn't quite have the volume to drive the amp. I'm pretty sure it would be great as a middle (P-bass) pickup, but for now, I'm going to keep this one in the bridge position and boost it a little bit with the on-board preamp.

I should have the Bass Sidewinders finished by next week. It's hard to say - I'm working on two different projects simultaneously during my off hours. I have the materials to make a 6-7 pickups, and I figure I should just build them up. Sanding the blades by hand is a PITA. I should probably sit down one of these days and figure out what kind of bench-top machinery I could use to polish them up more quickly.

I'm still waiting for some pickup winder parts to come in the mail. They should have been here a week ago. In the meantime, I'll keep casting parts.
 
Last edited:
  • Like
Reactions: wraub, Haroldo, BishopJP and 3 others
#197
Did you ever test your sidewinder pickup in anything resembling the typical P Bass position? In your opinion, would it "work" there as a single pickup solution in a passive bass? IIRC, your decision to go with an active preamp was more to do with the pickup placement than the pickup itself.
 
Last edited:
#198
NKBassman said:
Did you ever test your sidewinder pickup in anything resembling the typical P Bass position? In your opinion, would it "work" there as a single pickup solution in a passive bass? IIRC, your decision to go with an active preamp was more to do with the pickup placement than the pickup itself.
Click to expand...

For me, the Bass Sidewinder is all about looking badass more than anything. Don’t get me wrong - it sounds good, but it’s characteristics are like that of any other sidewinder. It has an extended high end, a neutral-sounding midrange and a fairly low to moderate amount of output. I think that’s largely due to its narrow sensing aperture.

To answer your question, I don’t know that it would best suited as a single passive pickup. If you’re looking to get a lot of twang like a Danelectro pickup, it could be really good for that. I haven’t tried this yet, but I think it would be great up by the neck in a short scale bass. Otherwise, I’d stick with using a preamp. I’ve been rocking it with my Funktronic 3-band preamp in my 7-piece R&B Band.
 
  • Like
Reactions: Novarocker and NKBassman
#199
Freekmagnet said:
For me, the Bass Sidewinder is all about looking badass more than anything. Don’t get me wrong - it sounds good, but it’s characteristics are like that of any other sidewinder. It has an extended high end, a neutral-sounding midrange and a fairly low to moderate amount of output. I think that’s largely due to its narrow sensing aperture.

To answer your question, I don’t know that it would best suited as a single passive pickup. If you’re looking to get a lot of twang like a Danelectro pickup, it could be really good for that. I haven’t tried this yet, but I think it would be great up by the neck in a short scale bass. Otherwise, I’d stick with using a preamp. I’ve been rocking it with my Funktronic 3-band preamp in my 7-piece R&B Band.
Click to expand...

Thanks! Always nice to rule something out rather than adding another thing to the extremely long list of stuff that I want to try. :)
 
  • Like
Reactions: Freekmagnet

Latest posts

Top Bottom
Back