recycling pickups

[KX36]

Hi all,

 

It's been a while since I've been on here, hope everyone's doing great. I've been off building amplifiers and learning a lot about electronics.

 

I rewired my guitar a couple of years ago, and as part of that I swapped my pickups out. I now want to try winding my own pickups and was thinking of saving some money by stripping down the old Epi ones and keeping everything but the wire.

 

Anyone here done this sort of thing before? any tips our advice would be much appreciated.

 

Cheers

Matt

[RaSTuS]

Welcome back Matt, there's a member here that makes pickups for a living, hopefully he'll notice this and be able to offer advice, just hang tight.

[damian]

Go for it...........Member Clint Searcy builds pickups; " Searcy String Works.".....Also, join the Semour Duncan Forum..................

 

Dang, if you can build amps and know electronics, re-winding PUs should be a breeze....I haven't built PUs yet myself, but had

 

planned to start to last year.....Still plan to..........

[KX36]

Thanks for the encouragement guys.

 

I am planning to experiment with making my own active pickups that don't have the drawbacks of EMGs etc (i.e. high compression, and output too high for my needs) because they aren't aiming for massive output for heavy distortion, but simply a different, hopefully better character to passive pickups. So this is going to be a bit more unusual and require more planning and experimentation than just getting a drill or sewing machine and bunging as much 42AWG on a bobbin as can fit.

 

The two hurdles I can see from here are getting the right gauge of wire and number of turns for the right output, resistance, capacitance and inductance; and getting the pickup apart without ruining it. IIRC, these HOTCH and 57CH pickups are wax potted (please correct me if I'm wrong), and I don't know how to get rid of that yet.

[RaSTuS]

Many use hair dryers to melt the wax away, sort of like a mini heat gun.

[Lefty Bill]

Hi Matt, maybe you could post some links for the amplifiers you've built, I'd be very interested in seeing some details.

 

I haven't rewound any pickup coils and don't know that I'll get interested in doing that, although building a winder with a counter wouldn't be too difficult.

 

One thing I haven't seen mentioned when I look at online info regarding winding pickups is.. if p-up rewinders are actually counting the number of turns of wire that were already on the pickups. Maybe there are specs listed for some popular pickup models.

I've read that in humbucker p-ups the separate coils in each p-up have a different number of turns (and also wound in different directions).

 

I suppose that removing a specific number of turns from p-ups that are considered too hot or harsh might result in better sounding p-ups without going to the extra effort of stripping the coils off, then starting over.

 

What I've found so far, is that some Epiphone covered pickups are not full of wax, but are basically open-coil type humbuckers with covers added. Wax can be applied to coils in manufacturing so that it impregnates the windings without filling the entire cover.

Additionally, it's not as difficult to split humbucker coils as some sources make it seem (recent Stew Mac video I saw showing how to get to the fine coil wire), but instead, it's fairly easy since there is an existing series link of insulated wire connecting the coils which is clearly seen after removing the tape.

When the linking series wire is cut, then the new 4-wire p-up cable is attached to the existing 4 coil leads.

 

Blueman335 has made numerous mentions of changing the magnet types used in various p-ups can dramatically change the sound characteristics.

 

There was a series of comments regarding the addition of a small value capacitor in series with a p-up's hot A+ lead to change a p-up's sound (not the same as changing a parallel connected tone cap).

 

And the good 'ol standby recommendation to adjust the knobs on the amp, or get a better amp.. and a cable change can make a difference, too.

 

Please keep the forum informed of your progress as we all benefit from exchanging information, and I'm fairly certain that numerous participants are curious about the technical aspects.

 

Bill

 

 

Hi all,

It's been a while since I've been on here, hope everyone's doing great. I've been off building amplifiers and learning a lot about electronics.

I rewired my guitar a couple of years ago, and as part of that I swapped my pickups out. I now want to try winding my own pickups and was thinking of saving some money by stripping down the old Epi ones and keeping everything but the wire.

Anyone here done this sort of thing before? any tips our advice would be much appreciated.

Cheers

Matt

[KX36]

Hi Bill,

 

The valve amp I built is my own design I made based on a great little textbook my Merlin Blencowe. It was all a big experiment with various circuits that aren't as common as those which Fender, Marshall and all who followed used to get some unique sounds. It's an EF86 based preamp, although done completely differently to the Vox AC15 circuit (which is just about the only circuit that everyone copies but was a bit of a gimmick at the time and has too much gain in 1 stage, making it generally excessively microphonic) and a single ended EL34 power amp for about 7W output. It's taking a lot of getting used to but I'm starting to find some settings I really like, not that I have the chops to play it to its full potential. I'll try to get some pictures here later, although it's not very handsome. Other than that, I have finished an overdrive pedal I started in about 2003 but lost the schematic for, I'm part way through designing and building my own channel switching 50W EL34 push-pull, I have various little circuits prototyped but not put to use and I'm contemplating building an AX84 amp too since I hang out there a lot these days.

 

As far as removing turns from a pickup, it would lower its output, making it quieter; as well as lowering the capacitance and inductance, so raising its resonant frequency; and lowering the resistance, so raising the magnitude of the peak at this frequency slightly. Passive pickups are a trade off between not overwidning incase resonant frequency goes too low (it's a low pass filter so you don't get much signal above this frequency) and underwinding incase the output falls too low.

 

Balanced coils will cancel the most common mode noise, so they'd be quieter, but they'll also cancel any more of the signal at certain frequencies. Effectively imbalance in a humbucker makes it slightly closer to a single coil in terms of tone but also in terms of noise. It depends how much noise you're willing to put up with for the tone.

 

A small value capacitor in series with the pickup will effectively be the same as a coupling capacitor in an amplifier, it's a high-pass filter. If it's large enough, it will pass all audio frequencies, if it's too small it will block lower frequencies. With the right value capacitor followed by a standard tone and volume control topology, it will effectively turn the tone control into a bandpass filter. As the tone control is turned down, bass and trebble are both lost and the passband is that near the pickup's resonant frequency, getting narrower as the control is turned. I can't see this being too useful to be honest, it's not as if it will change the pickup's resonant frequency.

 

Hope that helps,

Matt

[LPDEN]

God to see folks still undetaking projects. Brings me back to the days in the 70's when I built Tube radios with fellow hobbyists. Those old "boat anchors" were (and still are) alot of fun and educational.

[angle]

Welcomes! i am new here too.