Pickups Question

Bill Fall · Post by **Bill Fall** » 31 Oct 2002 6:44 am

This may have been discussed before, but do single-coil pickups get noisier or "hummier" with age -- like, say, old Tele pickups? Specifically, would it probably be a good idea to get the ones on my old Super Pro rewound on general principal?

Gino Iorfida · Post by **Gino Iorfida** » 31 Oct 2002 7:17 am

I dont know if they 'hum' more, however, I've heard that alnico magnets can 'weaken' sometimes. ALso they can tend to start to go microphonic (i.e. they squeal or howl at high volumes etc)-- the fix for this is wax potting.

Bill Fall · Post by **Bill Fall** » 31 Oct 2002 8:13 am

Thanks, Gino!

jerry wallace · Post by **jerry wallace** » 1 Nov 2002 11:20 am

Bill, microphonics are caused by "something" moving or vibarating..Noise/hum can also becaused by loose windings..It can be the wire, the magnets, the bobbin plates etc..

Yes as a pickup ages, these items can start to cause your problem as the condition of the pickup changes..Also changes in the location of the steel in relation to the amp and different setup locations can cause these problems.

One prime example I have seen many times is that sweat, from you hand, or some other liquid can seep down around a magnet into the coil..This can cause many different problems including yours..

If a pickup is wound and tensioned correctly wax potting is not necessary..It is a way to get rid of the symptoms but not the real problem..Also wax potting does effect the frequency response of a pickup..

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Jerry Wallace-2001 Zum: D-10,8+6, "98 Zum: D-10,8+8,Nashville 1000,Session 500 ,Session 400 head only amp,Tubefex,ProfexII, Artesia, New Mexico
http://communities.msn.com/jerrywallacemusic http://www.jerrywallacemusic.com

[This message was edited by jerry wallace on 01 November 2002 at 11:44 AM.]

Joey Ace · Post by **Joey Ace** » 1 Nov 2002 12:20 pm

http://steelguitarforum.com/Forum11/HTML/002628.html

Earnest Bovine · Post by **Earnest Bovine** » 1 Nov 2002 12:39 pm

If a pickup is wound and tensioned correctly wax potting is not necessary..It is a way to get rid of the symptoms but not the real problem

Any relative motion between magnet and wire will induce a current; these currents are the "microphonics" that we all want to eliminate. Even winding under high tension cannot completely immobilize all wires (and magnets). So potting seems liek the ideal solution.

..Also wax potting does effect the frequency response of a pickup

How can wax affect the electrical properties any differently from the air it replaces?

Donny Hinson · Post by **Donny Hinson** » 1 Nov 2002 4:10 pm

How can wax affect the electrical properties any differently from the air it replaces?

It's not the wax, per se, that changes the tone. Rather, it is the nature of taking some of the "looseness" out of the equation. Everything in the guitar vibrates a little when the guitar is played, including the pickup and its components. Removing, changing, or deading any of these "vibrating elements" can change the tone. Similar effects can be realized by tightening loose screws on a steel guitar, or changing to heavier/lighter tuning machines on a straight guitar.

jerry wallace · Post by **jerry wallace** » 1 Nov 2002 6:30 pm

Earnest, I agree with Donny..The wax potting makes the whole coil into one stiff lump..I have torn down a bunch and the coil comes out like a chunk of wire.. I have done some frequency response checks and this stiffening kills off some of the desirable tone and high end resonance..

While the air between the windings does allow some resonance..All of the Emmons and Sho-bud pickups from the 1960,s until now, never had a drop of wax in them..

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Jerry Wallace-2001 Zum: D-10,8+6, "98 Zum: D-10,8+8,Nashville 1000,Session 500 ,Session 400 head only amp,Tubefex,ProfexII, Artesia, New Mexico
http://communities.msn.com/jerrywallacemusic http://www.jerrywallacemusic.com

Earnest Bovine · Post by **Earnest Bovine** » 1 Nov 2002 7:24 pm

wax potting ... this stiffening kills off some of the desirable tone and high end resonance

The proof in in the experimental results. But I don't understand why this would be true. In fact as I see the physics, potting would improve high end response, but only a very small amount (impercepible).

Jason Lollar · Post by **Jason Lollar** » 2 Nov 2002 9:05 pm

An unpotted coil resonates at high frequencies you can hear it in the overtones created. It is subtle but once you recognize the sound it makes you can tell if a coil is unpotted just by playing it for a matter of seconds at meduim to higher volume not by tapping on it to hear the sound directly.
I am backing up Jerry by way of experience, done it, threw them in the wax potter and listen to it agian, many times.
Some people really like it and some people hate it but mostly not from the tone its due to overly microphonic pickups sensing things like your fingers tapping on the guitar or clunking noises when you throw a switch or just from squeeling that a porrly tensioned coil can make.
Once you throw it in the wax the top end detail dissapears.
Oddly enough if you solidify the coil in something hard and brittle like epoxy it can become microphonic because it now vibrates as one unit at high frequency.
Having experimented with different potting compounds under high pre-amp conditions I found that the idea is not to solidify the coil as I had always been lead to beleive its to dampen vibration of the coil, I would only have found that out under extreme conditions, its not as apparent just running a coil straight into an amp although some peole claim to be able to hear the difference between potting compounds, I can only tell if its potted or not

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