What magnets are used in the Aldrich pickups?

That would be blasphemy
I did a lot of research and pay 3x what others pay for their magnets, these are the real deal, identical to what was used in the early 60's not run of the mill magnets there.
 
How do you judge one magnet of the same type against another? Is it by overall strength? Inductance? For example, lets say I have two alnico 5 magnets, what would I be looking for/to measure to determine which one I want to use for a pickup?
 
Mudder":242ogzsj said:
How do you judge one magnet of the same type against another? Is it by overall strength? Inductance? For example, lets say I have two alnico 5 magnets, what would I be looking for/to measure to determine which one I want to use for a pickup?
Click to expand...

Unless the magnet is in the coil it isnt going to change inductance
You cant measure the properties that matter unless you have the right equipment unfortunately. Having the manufacturers specs helps.

Br is the measure of its residual magnetic flux density in Gauss, which is the maximum flux the magnet is able to produce. ( 1Gauss is like 6.45 lines/sq in)
Hc is the measure of the coercive magnetic field strength in Oersted, or the point at which the magnet becomes demagnetized by an external field. ( 1Oersted is like 2.02 ampere-turns/inch)
BHmax is a term of overall energy density. The higher the number, the more powerful the magnet.
Tcoef of Br is the temperature coefficient of Br in terms of % per degree Centigrade. This tells you how the magnetic flux changes with respect to temperature. -0.20 means that if the temperature increases by 100 degrees Centigrade, its magnetic flux will decrease by 20%!
Tmax is the maximum temperature the magnet should be operated at. After the temperature drops below this value, it will still behave as it did before it reached that temperature (it is recoverable). (degrees Centigrade)
Tcurie is the Curie temperature at which the magnet will become demagnetized. After the temperature drops below this value, it will not behave as it did before it reached that temperature. If the magnet is heated between Tmax and Tcurie, it will recover somewhat, but not fully (it is not recoverable). (degrees Centigrade)

These are the specs you need
 
Suhr":1mdg9gz9 said:
Mudder":1mdg9gz9 said:
How do you judge one magnet of the same type against another? Is it by overall strength? Inductance? For example, lets say I have two alnico 5 magnets, what would I be looking for/to measure to determine which one I want to use for a pickup?
Click to expand...

Unless the magnet is in the coil it isnt going to change inductance
You cant measure the properties that matter unless you have the right equipment unfortunately. Having the manufacturers specs helps.

Br is the measure of its residual magnetic flux density in Gauss, which is the maximum flux the magnet is able to produce. ( 1Gauss is like 6.45 lines/sq in)
Hc is the measure of the coercive magnetic field strength in Oersted, or the point at which the magnet becomes demagnetized by an external field. ( 1Oersted is like 2.02 ampere-turns/inch)
BHmax is a term of overall energy density. The higher the number, the more powerful the magnet.
Tcoef of Br is the temperature coefficient of Br in terms of % per degree Centigrade. This tells you how the magnetic flux changes with respect to temperature. -0.20 means that if the temperature increases by 100 degrees Centigrade, its magnetic flux will decrease by 20%!
Tmax is the maximum temperature the magnet should be operated at. After the temperature drops below this value, it will still behave as it did before it reached that temperature (it is recoverable). (degrees Centigrade)
Tcurie is the Curie temperature at which the magnet will become demagnetized. After the temperature drops below this value, it will not behave as it did before it reached that temperature. If the magnet is heated between Tmax and Tcurie, it will recover somewhat, but not fully (it is not recoverable). (degrees Centigrade)

These are the specs you need
Click to expand...

John,

Easy enough... :confused: :LOL: :LOL:
 
Even with all that data, is much of the decision making process as to which magnet to pick simply trial and error? I'm sure you start with some given values from other pickups/manufacturers and tweak from there...or can you take any magnet of a given variety and get close to what you need from adjusting the other factors in a pickup like wire type and winding?

Sorry to take up your time with what's probably a bunch of basics, if there is some recommended reading I'd check that out too.
 
Suhr":1t118qma said:
Mudder":1t118qma said:
How do you judge one magnet of the same type against another? Is it by overall strength? Inductance? For example, lets say I have two alnico 5 magnets, what would I be looking for/to measure to determine which one I want to use for a pickup?
Click to expand...

Unless the magnet is in the coil it isnt going to change inductance
You cant measure the properties that matter unless you have the right equipment unfortunately. Having the manufacturers specs helps.

Br is the measure of its residual magnetic flux density in Gauss, which is the maximum flux the magnet is able to produce. ( 1Gauss is like 6.45 lines/sq in)
Hc is the measure of the coercive magnetic field strength in Oersted, or the point at which the magnet becomes demagnetized by an external field. ( 1Oersted is like 2.02 ampere-turns/inch)
BHmax is a term of overall energy density. The higher the number, the more powerful the magnet.
Tcoef of Br is the temperature coefficient of Br in terms of % per degree Centigrade. This tells you how the magnetic flux changes with respect to temperature. -0.20 means that if the temperature increases by 100 degrees Centigrade, its magnetic flux will decrease by 20%!
Tmax is the maximum temperature the magnet should be operated at. After the temperature drops below this value, it will still behave as it did before it reached that temperature (it is recoverable). (degrees Centigrade)
Tcurie is the Curie temperature at which the magnet will become demagnetized. After the temperature drops below this value, it will not behave as it did before it reached that temperature. If the magnet is heated between Tmax and Tcurie, it will recover somewhat, but not fully (it is not recoverable). (degrees Centigrade)

These are the specs you need
Click to expand...


PPFFFTTT!!!!
I thought everybody knew this!!?? hehe :D
 
Mudder":oevbu7wt said:
Even with all that data, is much of the decision making process as to which magnet to pick simply trial and error? I'm sure you start with some given values from other pickups/manufacturers and tweak from there...or can you take any magnet of a given variety and get close to what you need from adjusting the other factors in a pickup like wire type and winding?

Sorry to take up your time with what's probably a bunch of basics, if there is some recommended reading I'd check that out too.
Click to expand...

The problem with change for no reason is you could be chasing your tail with no scientific double blind test.
Plus... you will have to disassemble and possibly destroy a pickup, also need to re-wax it. There is an explosive discharge built into the coil so when the magnet is removed both coils partially short out :D
It is easier to change the tone of a pickup through other methods such as coil dimension, wire insulation thickness, wire thickness, turns, winding pattern etc etc etc.
Especially when coming down to a humbucker since if the coil is not wound around the magnet then the alloy properties of the magnet do not mean that much compared to the Hr and Br which can only be had from serious test gear.

I would start with "The ABC's of transformers and coils"
 
Thanks very much for your input on this. I'll check out that book. I'll admit, I'm a bit of a geek over this sort of thing.
 
You must log in or register to reply here.
Back
Top