Mod your cheap pickups

[KennyLusk]

I found a fantastic article in the latest edition of Vintage Guitar magazine that shows you how to mod/upgrade your cheap pickups. The article focuses on strat style single coils but after a little research it looks like you can do this to humbuckers as well; and just as easily.

I won't go into the process too much here because it wouldn't be fair to VG mag. or the author of the article, but let's say you have a Fender Standard Strat (or Squier)...you know, the $300 models. It would cost you about $20 and an hour or so of your time to upgrade those stock pups to basically Fender's Texas Special pups (way over priced IMO). Man, remember when Texas Special's came stock in the mid '90's in their $300 MIM Strats?

Cheap stock pups are usually of the ceramic magnet variety, right?. Some people like that sound and that's awesome. It's all about what works for you, right? But a lot of people would prefer more clarity, a more authentically Fender [or Gibson] sound, which means Alnico II or V pole pieces [or bars] are usually preferred. This article shows you step by step with pictures how to do that and it's so simple it's not even funny.

Just a head's up. Here's a link to VG's web page. The article isn't available online unfortunately but the mag itself isn't that expensive and for this article alone is totally worth the price of admission. The article is called "Quick pickup fix" in the Tech section.



http://www.vintageguitar.com/current/

[Michael_Joly]

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[Michael_Joly]

Another cheap trick is to mod humbuckers - install a coil tap switch or "roll in" pot to go from humbucking to single coil.

When I worked at Stars Guitars in SF in the late 70s we had a six-way rotary switch mod for humbuckers that involved re-wiring both PU coils so you could get:

1. Front
2. Rear
3. Both, series in phase
4. Both, series out of phase
5. Both, parallel in phase
6. Both, parallel out of phase

Combine those combinations with the guitar's two volume and tone controls gives an amazingly wide array of tones from a single guitar. I had a '63 SG set up this way. It was most useful as a recording guitar rather than a stage axe where you just want to toggle the stock PU switch back and forth that Townsend effect.

We also did a single coil "humbucking mod" by adding a hum canceling coil (without magnet) underneath a Strate or Tele pickup. The magnetic field on the strings remained narrow to get those Fender tones, but the humbucking occured in the vertical plane rather than in the horizontal as in a Gibson humbucker.

All this stuff is fairly common now but was state-of-the art guitar mod'ing in the 70s.

[Jim Williams]

The 6 position pickup selector switch was first used on the Gibson L6-S. I had one back in the late seventies. I added 2 more of them and wired one to each humbucking Gibson pickup. That way I could select all the possible combinations including single coil options. It had like around 250 possible combinations of sounds. I then wired the "varitone" inductor with a variable cap select switch and a "depth" pot to allow adjustable notching. It then fed one of my active circuits.

Be advised that shoving some alnico pole magnets into those plastic import bobbins will not create a vintage strat pickup. Fender pickups have high Q's and that comes from winding the coil right onto the magnet pole pieces, not a piece of plastic spaced away as you find in the import molded designs.

Those import bobbins are good for one thing: hum cancelling. I use a circuit that feeds one of those coils into a phase shift/filter circuit. That is inverted and fed into a cancellation circuit. It is adjusted using a small trim pot. That way I can tune out the hum electronically while still using old vintage Fender pickups. The circuit draws 500 ua, has a 2 to 200k hz bandwidth and a 200 v/us slew rate. I can get a 80 db s/n ratio on my old Telecasters. The entire guitar is screened so no buzz, dead quiet.

I run it on a 9 volt battery that sits under the control plate. The pcb is 1 inch square and sits under the plate between the volume and tone controls.
It also offers a low output impedance. That removes cable and impedance loading effects and allows thousand foot guitar cables. It also drives headphones directly for silent practice. It's up about 10 db above normal guitar levels so it drives amps hard for a very full sound.

[suppositron]

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Those import bobbins are good for one thing: hum cancelling. I use a circuit that feeds one of those coils into a phase shift/filter circuit. That is inverted and fed into a cancellation circuit. It is adjusted using a small trim pot. That way I can tune out the hum electronically while still using old vintage Fender pickups. The circuit draws 500 ua, has a 2 to 200k hz bandwidth and a 200 v/us slew rate. I can get a 80 db s/n ratio on my old Telecasters. The entire guitar is screened so no buzz, dead quiet.

I run it on a 9 volt battery that sits under the control plate. The pcb is 1 inch square and sits under the plate between the volume and tone controls.
It also offers a low output impedance. That removes cable and impedance loading effects and allows thousand foot guitar cables. It also drives headphones directly for silent practice. It's up about 10 db above normal guitar levels so it drives amps hard for a very full sound.

Jesus Christ that is awesome.

[Jim Williams]

As nice as they are in the studio, these are best used live and loud. The pickups are soaked in wax. Then they are wrapped in adhesive copper foil. That removes all the hf buzz noise. The bridge is glued down with silicon glue to remove any vibrations. The bridge Tele pickup has that copper plated steel plate on the bottom removed. That is a source of squealing on Telecasters. I used surgical latex hose instead of steel springs, the springs are magnetic and can also squeal and feed back. I used locking nuts under the pickup to support and mount it. The entire insides are covered with copper foil including the pickup cavities. The string ground was removed and replaced with a .022uf 250 volt polypropylene film cap. That prevents shocks from badly grounded PA systems, something all guitars should have.

The results are a Telecaster that is silent and stable under very high SPL's. All Telecasters are unstable if you play next to a 120 watter cranked up. Mine are stable and quiet. No squeals, no feedback unless you let a string loose. The guitar behaves like a 1965 strat, full up, full control, full Hendrix feedback with total control. Tele players ask me all the time how do I do it.
They see a guy with a stock looking Telecaster and a stock looking 1966 Fender Showman amp and it sounds like Voodoo Child! Anyone knowing that combination realizes it should sound like Buck Owens. The amp is also reworked but looks stock. The vibrato channel is a Marshall Super Lead 100 preamp. Think Buck Owens on acid.

[Electro-Voice 664]

Think Buck Owens on acid.

Like the Flying Burrito Brothers?

[KennyLusk]

Think Buck Owens on acid.

I like both actually.

I posted the article as a heads-up for folks wanting to upgrade their cheap stock pups and Jim, you and Michael both posted awesome ideas on how to go the extra 9 yards and then some.

Cool posts. My head is still spinning from Jim's mods though, I have to admit. Wild stuff man.

[Michael_Joly]

Man, does all that stuff bring back memories Jim - copper foil grounding strips in the PU and pot cavities painted over with graphite paint, humbucking pickup covers with the centers milled out, "brass mass" bridges, nuts, and stop tailpieces, "string return" acoustic guitar pickups (a single Alnico magnet under the strings, the strings wired in series and fed into a current amp, best amplified acoustic sound I've ever heard). We did all kinds of amp mods - microphonics reduction, master gain pots, effects loops, preamp outs, hum balancing pot installation, micro power output switch.

speaking of Telecaster - while at Stars I built a hollow body tele from scratch, neck copied from an early Esquire, single hand wound PU, and the only all-brass bridge with six adjustable saddles ever made. Body is maple routed out, neck is three pieces of maple with opposing grain - set up this guitar over 30 years ago and the truss rod has never needed to be adjusted. Top is mahogany. The whole thing, neck included is painted red. Gibson style frets though as I was playing an SG at the time.

btw - Klaus Heyne was working across town at Don Weirs Music City as a guitar tech while I was at Stars. We never crossed paths though.

[ashcat_lt]

"string return" acoustic guitar pickups (a single Alnico magnet under the strings, the strings wired in series and fed into a current amp, best amplified acoustic sound I've ever heard).

Are you at liberty to discuss specifics on this? Google isn't getting me anything. Specifically I want to know what you mean by "strings wired in series".

[Michael_Joly]

Sure. This idea predates Google by quite a few years and I've never seen it documented in print.

I believe it originated in the early '70s with Ron Rickersham, the Grateful Dead's chief scientist and Alembic founder. It was passed from him to Stars Guitars founder Ron Armstrong. The idea and implementation is quite simple - a magnet is mounted below the strings and the strings are wired together to create a "moving coil". Earlier I said they were in series, but now that I think about it, it may have been a combination of Series / Parallel in order to balance top and bottom output.

Anyway, as you recall from your fourth grade science class - when a coil of wire moves and cuts across magnetic lines of flux a current will flow in the wire. We used to use a turntable "moving coil pickup transformer" (very high input impedance) to sense the current flow and not load it down. Some versions followed the transformer with a FET output stage.

The more I think about it, I believe the nut was brass. This would tie all the strings together electrically at that end of the guitar. Then pairs of strings were brought together in a particular combination that gave the best balance.

Unfortunately this was almost 35 years ago and I haven't set up a guitar like this since then and can't rattle off cookbook instructions.

But you have to believe me, this was the most pure amplified acoustic sound I've ever heard. It is simply the sound of the strings moving. To the extent that the guitar's body influenced string response that sound is also amplified. Of course you don't get all of the woody boxiness of the resonating surfaces but a surprising amount comes through. Much more natural sounding than any Piezo (yuck) or electric guitar style PU.

It cannot be a commercial product (only a service) because it requires modifying each guitar individually to mount the magnet and wire up the strings.

We built string return PU basses and E. guitars also. "neck through body" Alembic style. The basses were very succesful but the electric guitars sounded too clean - like amplified acoustics.

Despite it relatively short life span, Stars Guitars had a major influence on electric guitar and amp builders. The first graphite neck basses by Rick Turner were prototyped at Stars. We were right next door to a huge pre-tour rehearsal facility so all the big Bay Area guitarists were regulars at the shop. One day we were called on to "age" a Peavey guitar to make it look like Neil Schon of Journey actually played the thing on tour before it was to be awarded as a contest gift. Ted Nugent's Birdland probably still has the little bits of masking tape we stuck inside that said "Hi Ted, Patti Smith" on them (they had famous row on late nite TV just before so we though it would be cute to surprise Ted way in the future when the glue dried out and the paper started to flop around in his axe. Punk humor I guess).

The knowledge base at Stars was vast. Those guys were 15-20 years older than than me at the time and I had some great 'Nam vet mentors. A very formative first job out of college.

[ubertar]

I didn't know there was a name for that. There was a guy who wrote an article about this idea in experimental musical instruments magazine in about '92, IIRC. He didn't use transformers, though, so his output was really low. I tried this with high impedance output ribbon mic transformers a while back, and it works great. My microtonal guitar (picture below) works on this principle, and it sounds more like an acoustic than an electric. I had a provisional patent on using this idea for violin-family instruments, as well as guitar, but it expired. I was in talks with a company about developing it, but they eventually decided it wasn't something they wanted to invest in. I wasn't aware anyone else had done this before using transformers. I've been keeping this pretty much under my hat, but since it's been done, publicly, I guess there's no need to keep quiet anymore.

[ubertar]

I think of it as less like a moving coil dynamic than a ribbon. A string moving in a magnetic field is more like a ribbon than a coil.

[Michael_Joly]

There was a guy by the name of Lane Poor, a Stars alumnus, who started a bass pickup company in Rhode Island. He was a school yard buddy of Jack Casady of the Airplane. I believe Lane was doing some string return bass retrofits around '79 through the early '80's. Interesting side bar - its rather fascinating to find out how many rock stars of the '60's came from very privileged economic backgrounds - prep school, music lessons, vacation house in the country, international travel / residency with mom and dad (the diplomats), gear allowances - the whole deal. Their bios don't usually mention this. I could name a big handful of '60s stars with that kind of pedigree but hid it under long hair and bell bottoms as they re-tooled Southern black music for white kids.

When I moved on from Stars and went to work for David Blackmer (dbx Inc. later Earthworks) in his motion picture sound company Kintek Inc. we had a log / anti-log current amplifier that was used to amplify the output of 35mm motion picture soundtrack solar cells. This amp made a perfect low-noise current amp for the string return pickup.

btw - David got his start designing low-noise instrumentation amplifiers for the Mercury space program telemetry system. This work led to his two key patents for his low distortion voltage controlled ampfier and RMS level sensor. The basic building blocks that made dbx compressors and noise reduction systems possible.

re: "moving coil" vs "ribbon" - a corrugated ribbon in a magnetic field is a specific application of the general principle of a "moving coil" - even if the "coil" is a single turn of wire, the physics term for this object is a "single turn coil", and if it is free to move in response to some stimulus it is a "moving coil".

[ubertar]

re: "moving coil" vs "ribbon" - a corrugated ribbon in a magnetic field is a specific application of the general principle of a "moving coil" - even if the "coil" is a single turn of wire, the physics term for this object is a "single turn coil", and if it is free to move in response to some stimulus it is a "moving coil".

True, but we don't call a ribbon mic a moving coil mic (even if a physicist or electrical engineer who doesn't do recording would)... we use that term for mics with a coil of wire attached to a diaphragm. You are technically correct. No point in getting into a semantic argument. I just find it closer in concept to a ribbon mic than a moving coil mic. I was expressing how I think of it-- I wasn't saying your way was wrong.