Cryogenic treatment of guitars warning

[Enzo]

I wasn't pointing at an individual.

Over in the amp section, someone may post that he plugged his speakers into the "speaker input" on the back of his amp. Well, that is clearly wrong, as the rear panel jacks are output TO speakers. But I knew what he meant. I might correct the usage, but at the same time I won;t pretend not to understand. I thought it was pretty clear what everyone was talking about, regardless of the correctness of the terminology.

No one gets a pass because the "other guy was wrong".

[The Dude]

Chuck H is unclear on the concepts and became both defensive and abusive with called on it.

Let's be fair. He's not the only horse in that race.

[DrStrangelove]

If you don't like people correcting you, stop posting.

I'm cruising.

Well overdue, at that.

[salvarsan]

It is all well and good That we use proper terminology, but is there real confusion here about the concepts?

Yup. Others have noted that, too.

Chuck H is unclear on the concepts and became both defensive and abusive with called on it. Does anyone else think that was questionable behavior for a moderator? You can't put a moderator on your ignore list, either.

Speakina moderators, Dr. Strangelove, a self-styled IMmoderator, is posting again.

[Enzo]

I don't have a dog in this fight, I don;t deal with pickups.


No, I do not include that I USE guitar pickups to make sound while servicing amps.

I don;t make them or service them. I have been watching this thread, it is such a classic internet faceoff. Like tube versus solid state, or whatever, the same relative positions were grabbed and let the shit slinging begin. Everyone wants to hold their turf.


I see a mighty argument over the magnet "powering" the pickup. The disagreement? Power meaning providing some sort of actual power, while the pickup is passive on the one side. OR power means that which makes the thing function on the other. OK, there is no "power" in the passive pickup. But without the magnet it doesn't work. Is that really an argument?

My introductory physics courses and electronics courses were 50 years ago now, but we learned that a conductor moving in a magnetic field induces a current in the conductor. It didn't care whether the conductor moved in the field or if the field was moved around the conductor. The conductor could be plain old non-magnetizable copper.


It is all well and good That we use proper terminology, but is there real confusion here about the concepts?

[Chuck H]

If you do not like people correcting you, then stop posting nonsense.

If you don't like people correcting you, stop posting.

I'm cruising.

[Chuck H]

Maybe flip flop was too aggressive. I didn't say a thing about north/south. Certainly the polarity is moving. It's making AC! gosh, audio components can't change polarity without Barkhausen distortion? good to know. I'll alert the transformer manufacturers immediately. This is just another semantic nit with a contrary agenda. I tried to bury the hatchet but you act like a petulant child. Maybe you enjoy a circle jerk but I don't. You won't be hearing from me anymore on this thread.

[Rick Turner]

The issue seems to be moisture, but if it's a wax potted coil, that shouldn't be a problem.

The info re. Alnico not particularly liking deep cold is interesting if for no other reason than it shows that cryo does have an effect on Alnico, even if the effect is a negative one. So at least we know that we can't say that there's no effect.

[salvarsan]

Someone should ask them if cryo only, no heat treatment is an option.

[big_teee]

CryoPlus Inc. in Wooster Ohio does small runs under 1 pound for $17-25 depending on how you specify it (parts? electronics? tools?).

Their generic process includes a 200F pre-heat to remove water, 10 hours at -300F, and a later 300F annealing UNLESS you specify otherwise. 300F is a little close for comfort for the P155 magnet wire insulation (155C = 311F).

CryoPlus Inc contact info:
2429 North Millborne Rd
Wooster, OH 44691
Phone: 330-683-3375
Fax: 330-683-2653
Email: Kathi@cryoplus.com

If you phone later in the day, you are quite likely speaking with the owner, Kathi Bond, so be nice.

Don't think The 300f will be good for pickups, especially if a plastic bobbin humbucker is involved.
I wax potted the strat pickup, at 300f, doubt there will be any wax left.
I vote for 150f before and after.
T

[salvarsan]

I sent the Strat Single Coil I made for testing, to Rick Turner.
He should have it, by monday.
T

bravo, Terry.

The usual way these things happen is a cryo treatment over the weekend and return shipment on Monday and Tuesday.

[big_teee]

I sent the Strat Single Coil I made for testing, to Rick Turner.
He should have it, by monday.
T

[DrStrangelove]

Inexpensive Cryo Treatment services

CryoPlus Inc. in Wooster Ohio does small runs under 1 pound for $17-25 depending on how you specify it (parts? electronics? tools?).

Their generic process includes a 200F pre-heat to remove water, 10 hours at -300F, and a later 300F annealing UNLESS you specify otherwise. 300F is a little close for comfort for the P155 magnet wire insulation (155C = 311F).

CryoPlus Inc contact info:
2429 North Millborne Rd
Wooster, OH 44691
Phone: 330-683-3375
Fax: 330-683-2653
Email: Kathi@cryoplus.com

If you phone later in the day, you are quite likely speaking with the owner, Kathi Bond, so be nice.

[salvarsan]

Boy, where's a metallurgist when you need one... I'm not one, sadly, but it looks like the hardening mechanism of cryogenic treatment is preciptation. What phases are present in (whatever grade) Alnico, what precipitates do you expect to form, and how will that affect the magnetic properties?

I don't presume to be a metallurgist, but I don't need to be one, only scientifically literate.

Alnico separates into iron-cobalt alloy crystals in a nickel-aluminum matrix. The carbon content (usually unstated) is important and has a profound effect on the crystal size as the alloy solidifies. 1% carbon present entirely as iron carbide means 14% iron carbide in the sample. Iron and nickel carbides are historically well-elucidated. More carbon -> smaller crystals.

(NB, the carbon is rarely entirely metal carbide, existing instead as an equilibrium mixture of carbon and carbides whose proportions are determined by post-melt treatment. -drh)

The metal carbides are so thermodynamically unstable that they disproportionate under mechanical stress...(cough!), er, decompose when you beat on them. Dimensional thermal coefficients (shrinkage) of the component metals are down in the 0.1% to 0.5% range for ambient-to-cryogenic temperature cycling, so the shrinking force drives carbon precipitation from metal carbides.

Less well-known is that tiny amounts of niobium are an effective carbon getter in the magnet alloys. The NbC+Nb₂C are more stable than iron or nickel carbides and may be removed from the melt as brown sprue, however too much free niobium reduces the already low permanence of alnico.

LN2 is, what, rougly -195C?

77K for a few of us.

Just degauss your magnets 10% and call it even.

Okay, comedian. (heaves long quiet exasperated sigh)

The dockamint statement referred to the alnico magnetic field temperature coefficient and the decrease in remanence at temperature, not the remanence and permeability changes attributable to microstructural changes from cryogenic treatment.

The alnico remanence changes are not so irreversible and should be recovered by remagnetization if you really need that last 10%, at least if you find the industry's Permanent Magnet Guideline 1988 doc credible in the least.

I haven't looked at the properties of magnet wire, but since any alloying elements will reduce its conductivity (as will cold work) I have to assume it's fully annealed (and thus fully softened) or at least as much as possible to get the highest conductivity in %IACS. (percent of the International Annealed Copper Standard... weird coicidence, huh?!) - No solute-rich phases from which to generate precipitates means no precipitation.

I haven't looked at copper+cryo much either, however, precipitation is not the sole mechanism by which metal/alloy microstructure changes. Copper has mechanical creep even at 77K, to see it written. Not much info on that yet, sorry.

And just to continue the overall tone of the thread: using a sample size of 1 plus 1 control does not void the null hypothesis.

But ... but ... but ... what about sample skew and kurtosis?

Honestagawd, I'm not busting your chops Paul, but I have tried hard to put forth a scientific basis for the fact that cryogenic treatment affects pickup materials and are likely to have audible manifestations, only to be told it's a useless conjecture by one sociopath and exhorted to die in a fire (twice) by another, a self-styled moderator who can not be put on the ignore list.

Far be it from me to suggest that they both do something profane with themselves, their mothers, and the horses they rode in on. No, I'd never write such a thing here.

[potatofarmer]

Boy, where's a metallurgist when you need one... I'm not one, sadly, but it looks like the hardening mechanism of cryogenic treatment is preciptation. What phases are present in (whatever grade) Alnico, what precipitates do you expect to form, and how will that affect the magnetic properties?

Anyone got a scanning electron microscope in their garage?

Alnico has a low temperature coefficient for the quantity Br. An irreversible loss of magnetization of about 10%
has been observed after operation at -190 0C [74], [77]. The lowest suggested operation temperature for Alnico
is -75 0C. The demagnetization curves of Alnico at different temperatures are shown in Fig. 42.

http://www.nikhef.nl/~jo/quantum/qm/prr/ET-026-09.pdf

LN2 is, what, rougly -195C? Just degauss your magnets 10% and call it even. Also I managed to find reference #77 in the collections of two local-ish public libraries. Since the idea of subjecting alnico alloys to cryogenic temperatures was already fleshed out back in 1962, yinz might want to get your library cards out.

I haven't looked at the properties of magnet wire, but since any alloying elements will reduce its conductivity (as will cold work) I have to assume it's fully annealed (and thus fully softened) or at least as much as possible to get the highest conductivity in %IACS. (percent of the International Annealed Copper Standard... weird coicidence, huh?!) - No solute-rich phases from which to generate precipitates means no precipitation.

And just to continue the overall tone of the thread: using a sample size of 1 plus 1 control does not void the null hypothesis.