Hey JCH..... thoughts on Pickup recipe.

[muttley600]

The other day I was gigging with a pickup band and took along the HR guitar we all put together last year. The more I played it the more I got to thinking of that Charlie Christian sound that comes from that ES 150 monstrosity.. I want to work on getting it closer.

The pickup that put me in mind of the CC tone was the front PAF style that you cooked up, played clean through a Fender Princeton mostly flat with a touch of plate reverb.

The pickup was your spec and from memory was AlNiCo 5 CCW north up, 9,500 turns 42 awg with moderate scatter scatter built P90 style. I know the original CC pickups had hunking great cobolt magnets and used 38AWG wire with a bar instead of poles.

Question is what would you change to try and get it closer to that elusive Christian tone? It's going to go on an old Jazz box I made years ago about the same size as the ES150...

Any other observations would be good.

 

[JCH]

The other day I was gigging with a pickup band and took along the HR guitar we all put together last year. The more I played it the more I got to thinking of that Charlie Christian sound that comes from that ES 150 monstrosity.. I want to work on getting it closer.

I'm glad that you're going for the tone rather than a replica. Here's a little video that's a great comparison between the familiar tone of a PAF compared to a CC. If it were up to me I'd change the name of the pickup from Charlie Christian to Barney Kessel.

The pickup that put me in mind of the CC tone was the front PAF style that you cooked up, played clean through a Fender Princeton mostly flat with a touch of plate reverb.

I bet it sounded great. One of my favorite guitar sounds is that of a clean P-90 mounted at the neck.

The pickup was your spec and from memory was AlNiCo 5 CCW north up, 9,500 turns 42 awg with moderate scatter scatter built P90 style. I know the original CC pickups had hunking great cobolt magnets and used 38AWG wire with a bar instead of poles.

They were huge at almost two pounds. The technology was pretty new back then, and I assume the design process was to try and emulate the sound of an acoustic. Nobody knew how an electric was supposed to sound so they're very high fidelity compared to what's now considered normal. At the time they were also played through hi-fi type amps that didn't flavor the tone much.

Question is what would you change to try and get it closer to that elusive Christian tone? It's going to go on an old Jazz box I made years ago about the same size as the ES150...

First off, I'd try to keep in under the footprint of a P-90. I'd start by making the coil form much taller, and the core bigger. Instead of two magnets, maybe just one AlNiCo2 bar. I'd pack as much AWG38 as would fit on it. After evaluating the tone of that, I'd experiment by swapping magnets, and removing wire, say 100 turns at a time, and re-evaluate the differences.

Any other observations would be good.

CC pickups are very low z. This causes the resonant peak to be out of a guitars range. This is the key to their tone. It's a very balanced sound without the flavoring of a pronounced peak in response to certain frequencies. If you use a coil that's roughly the same size, and similar wire you should be able to experiment with magnets to get yourself pretty close. Easily within the range that you could EQ into what you're looking for.

I'm anxious to hear what you come up with.

 

[muttley600]

Seen that before. Great vid. The CC pickup should remain the CC pickup. He did it first..

I was really lucky to see Barney Kessel when I was about 12. A friend took me along to a solo show he did in a local theatre. He played for 2 1/2 hours and didn't repeat a single phrase that I could spot. He actually asked people to try and pull him on it... That show was one of the main reasons I got into jazz guitar 40 years ago.

Any way. thanks for the input. I think the design rational at the time of the big hunking pickups was that it had to work in big bands for solo players and also against the increased use of larger and better public address systems. The tone that resulted was a happy coincidence IMHO. For sure those big cobolt magnets were all they had back then so they had to use them.

Based on what I know know about pickup winding (I have managed to do about 60 or 70 or so in the last year to get my technique and understanding down) and your valued input here's what I intend to do. If it all works I'm gonna send you one as a thanks for turning me onto this dark art a while back. I'd always dodged it as I am and will remain primarily a guitar builder but I'm really enjoying the ride and the learning curve.

Agreed on keeping it to the p90 footprint. To work for me and also any future customers that may want one it's a no brainer. Ultimately I'd like to be able to get it floating on the scratch plate as most of what I do now works that way. That will also help with getting readily available parts and casings as a start point.

I'm waiting for the 38awg wire to arrive when it does I'm going to mock up a pickup as per the HR design guitar and do a comparison with that. I can get quite a bit more wire on those bobbins if required.

I'm going to mock up some p90 bobbins that will include a bar rather than pole pieces see where that gets me. I'll make them taller as suggested based on the heavier wire. I know that the current CC style p/up's made by others on the market don't use 38awg but I can always switch if that seems the way to go. I'm after getting the right induction rather than a specific reading so a lot will be eel and trial and error.

A few further questions if I may.

On the original pickups that got me started thinking on this I used quite a heavy brass baseplate. What effect would you suggest different materials and bassplate mass will have?

Apart from balancing the individual string output what effect would you say I can expect when using a bar instead of pole pieces?

I'll post up pics as usual when I get started.

 

[JCH]

Based on what I know know about pickup winding (I have managed to do about 60 or 70 or so in the last year to get my technique and understanding down) and your valued input here's what I intend to do. If it all works I'm gonna send you one as a thanks for turning me onto this dark art a while back. I'd always dodged it as I am and will remain primarily a guitar builder but I'm really enjoying the ride and the learning curve.

Wow, thanks! Originally I had no idea how much time and focus my pickup making was going to require. Something that's so simple on the basics becomes very involved after you build the first one. What fun though.

Agreed on keeping it to the p90 footprint. To work for me and also any future customers that may want one it's a no brainer. Ultimately I'd like to be able to get it floating on the scratch plate as most of what I do now works that way. That will also help with getting readily available parts and casings as a start point.

The geometry, and size of the coil might be an obstacle if you want to top mount.

I'm waiting for the 38awg wire to arrive when it does I'm going to mock up a pickup as per the HR design guitar and do a comparison with that. I can get quite a bit more wire on those bobbins if required.

38 is pretty big. You'll be surprised. This is a coil size calculator that one of the members on the pickup winder's forum devised. It'll tell you how many turns of wire you'll be able to get on a specific coil. It's a very handy tool for custom designs.Coil Estimator

I'm going to mock up some p90 bobbins that will include a bar rather than pole pieces see where that gets me. I'll make them taller as suggested based on the heavier wire. I know that the current CC style p/up's made by others on the market don't use 38awg but I can always switch if that seems the way to go. I'm after getting the right induction rather than a specific reading so a lot will be eel and trial and error.

That's how I'd start, and for the same reasons.

On the original pickups that got me started thinking on this I used quite a heavy brass baseplate. What effect would you suggest different materials and bassplate mass will have?

More metal will cut the high frequencies some. You could experiment with different non-ferrous types to see what happens.

Apart from balancing the individual string output what effect would you say I can expect when using a bar instead of pole pieces?

Because bars have more mass than screws they tend to sound warmer. This will likely help get the tone you're after.

Sorry for the quick answers, but I'm on my way to work in a few minutes.

 

[muttley600]

The geometry, and size of the coil might be an obstacle if you want to top mount.

Ultimately I want to have it so that is pickguard mount not surface mount. I'm going to work on the sound first then reduce the size if possible. One thing at a time.

38 is pretty big. You'll be surprised. This is a coil size calculator that one of the members on the pickup winder's forum devised. It'll tell you how many turns of wire you'll be able to get on a specific coil. It's a very handy tool for custom designs.Coil Estimator

Yeh but I'm gonna load it up as much as possible and take it from there, see what happens. I'm mocking up some bobbins now so I'll see what the calculator says compared to real life and get back...

More metal will cut the high frequencies some. You could experiment with different non-ferrous types to see what happens.


Because bars have more mass than screws they tend to sound warmer. This will likely help get the tone you're after.

Sorry for the quick answers, but I'm on my way to work in a few minutes.

I will experiment with different baseplates. I'm making a few bobbins both p90 and our own HR style with bars to do the first comparisons. I'm going to have to be imaginative about mounting as the bar is going to cut through the traditional p90 mounting holes. I'll chuck up some pics later. Just waiting on the wire now. I'm thinking stay with wind direction and polarity from the HR recipe? No need/benefit to change that right?

 

[JCH]

I'm thinking stay with wind direction and polarity from the HR recipe? No need/benefit to change that right?

You're good. It makes no difference on a single pickup guitar.

 

[muttley600]

Yeh thats what I thought. Gonna keep it the same so I can keep one on the HR which has two p/ups as you recall.

Here are a few of the mockup bobbins that I knocked up last night. Ignore the size as they look bigger than the p90 bobbins. Thats my crappy phone camera. They are actually the same footprint. I have increases the bobbin spacer to 8mm from the traditional 6 mm thats should allow me to get around 20% more copper in there. We shall see. Still waiting on the 38awg so I'm going to make up some flatwork for the polepiece bobbins next and dig out some baseplate material for all of them.

I still need to figure out a way to attache the baseplate to the bar pole piece version. I guess I could drill and tap into the bar but there should be an easier way...

 

[JCH]

Here are a few of the mockup bobbins that I knocked up last night..... I have increases the bobbin spacer to 8mm from the traditional 6 mm thats should allow me to get around 20% more copper in there....

I really like the look of those. I hope 8mm is enough room for you. I'm tellin' ya that 38's big. Around 10mm or about the height of a strat coil is what I was thinking.

I still need to figure out a way to attache the baseplate to the bar pole piece version. I guess I could drill and tap into the bar but there should be an easier way...

There's no real need to have a mechanical joint between the rail and baseplate. Let it extend through the bottom of the bobbin the thickness of the magnet /s. Butt the magnet right up to the bar. Connect the leg of the coil that you're using for ground to the baseplate like you would on a humbucker. It can all be glued together.

 

[muttley600]

I really like the look of those. I hope 8mm is enough room for you. I'm tellin' ya that 38's big. Around 10mm or about the height of a strat coil is what I was thinking.

There's no real need to have a mechanical joint between the rail and baseplate. Let it extend through the bottom of the bobbin the thickness of the magnet /s. Butt the magnet right up to the bar. Connect the leg of the coil that you're using for ground to the baseplate like you would on a humbucker. It can all be glued together.

It may well need a bigger bobbin. It may well need to be duel wrapped, I know at least one winder that does that on some of her stuff. Like you advised I'm going to try it out and change one thing at a time. I'll let you know how much goes on there. The original bobbins for the CC were not significantly bigger.

Agreed the baseplates can be glued but my thinking at present is that I want to be able to swap them and the magnets out for testing in the short term. Ultimately I would do as you suggest on the finished item. Then there is the mounting method. I still have to deal with that. I'm thinking just a rubber friction fit or a little velcro for testing purposes but will need a solid mount when it's installed finished?

Made up some pole piece bobbins last night pics later..

Should be winding them next week. I'm going to look about to see what gear I have in the workshop for doing some controled recording of the results. Nothing fancy but hopefully reliable for basic comparison.

Thanks again for the input. Much appreciated.

 

[muttley600]

Also on the bobbing gap width. Using wood takes away a bit of the space as I have to leave the flatwoork a bit thicker for rigidity. Getting Forbon here is not easy at least in manageable quantities. I have some on order from a knife maker that I will use to mock up some bobbins with when it arrives. Hopefully that will help things.

Did you ever move on that vacuum former. I'm just about to build a small one for p/u covers and am going to experiment with resin casting also...

All this is distracting me from my work but I love trying out stuff...

 

[JCH]

Did you ever move on that vacuum former. I'm just about to build a small one for p/u covers and am going to experiment with resin casting also...

I didn't get past gathering some of the things to make one. I'm still anxious to give it a try. Maybe this winter.

All this is distracting me from my work but I love trying out stuff...

Me too. I never get bored of experimentation. Sometimes frustrated, but never bored.

 

[muttley600]

First lot of test bobbins are ready for winding. Hopefully I'll get it tomorrow. I have attached the base plates on the bar bobbins with a few small bolts threaded on to a timber threaded lug so I can swap out different base plates easily. Not perfect but they are at least secure... The Pole piece bobbins are threaded right through the base plate so not a problem there.

 

[muttley600]

...............

 

[muttley600]

OK here we go. The 38awg wire arrived yesterday and I've had time to load up the bobbins for the two HR style pickup bobbins.

I managed to get 3500 turns on to each and ended up with a reading of 1.2 ohms. A little on the low side to say the least but I know from looking at a few originals that they were pretty low as well and it's the inductance we are interested in not the DC resistance in any case. That should be effected by the choice of magnet mostly and there location.. They still chucked out quite a bit of output so I loaded them up in the guitar and whoopie plenty of output with a couple of ceramic magnets.

General observations so far.

Bar pole piece.... Louder and possible a little more mid range.
Individual pole piece.... Brighter and possibly a little more separation.

I shall try and grab a few quick video clips of each one and post them up. I shall work out a way to capture better sound clips when I have some more pickups done for comparison.

The tone so far is definitely more "vintage" than the original recipe which were wound with 42awg and coupled with alnico 5 magnets. I'll stick a comparative sound clip of that up in good time as well.

 

[muttley600]

One of the problems getting more wire onto those bobbins is that the eyelets on the underside get in the way. The P90 bobbins shouldn't be a problem in that regard as the eyelets can be located away to the edge. I'm going to wind them next and dig out a guitar that I can use as a tester for all the pickups. P90's won't fit in the HR guitar...

 

[JCH]

One of the problems getting more wire onto those bobbins is that the eyelets on the underside get in the way. The P90 bobbins shouldn't be a problem in that regard as the eyelets can be located away to the edge. I'm going to wind them next and dig out a guitar that I can use as a tester for all the pickups. P90's won't fit in the HR guitar...

Those look nice. Instead of eyelets you could use lead wires similar to a humbucker, and utilize the wasted room on those bobbins.

 

[muttley600]

Those look nice. Instead of eyelets you could use lead wires similar to a humbucker, and utilize the wasted room on those bobbins.

I think I will do that in future at least for 38awg. The induction is pretty good with just 3500 turns and the out put matches the single coil on the bridge pretty well.. What would the extra thousand or so turns give me do you recon?

Currently the only draw back to my ears is that the unwound top B and E are a little "quacky" for want of a better word. I'm also guessing that potting is going to help as there is some very slight hint of microphonics going on there. I wound them pretty tight as the 38awg is twice as tough as the standard 42 awg.. I'm guessing there is still quite a bit of space in the coil though and there is probably some slack on the mid point of the bobbin where the wire doesn't lie as tight.

 

[JCH]

Try putting a 1k resistor in series with the pickup. See what it does to the tone.