Currently my Aleph is using 1 Ohm DALE 5W for the Source resistors, and I want to replace them with 0.5 Ohm 5W resistors…
I just know now that not all wire-wound resistors are inductive. I have PAINTON resistors. In the body written:
200M/A
0.50 Ohm 1%
PAINTON
ENGLAND
TYPE 406A
70.45
The lead is made from strange material, such that it is too dificult to solder. Are they inductive?
I just know now that not all wire-wound resistors are inductive. I have PAINTON resistors. In the body written:
200M/A
0.50 Ohm 1%
PAINTON
ENGLAND
TYPE 406A
70.45
The lead is made from strange material, such that it is too dificult to solder. Are they inductive?
Googling reveals some connections with Bourns and Meggit.
In all cases the name Painton shows up in highly professional material and military equipment.
But I can't answer your "inductive" question.
/Hugo
In all cases the name Painton shows up in highly professional material and military equipment.
But I can't answer your "inductive" question.
/Hugo
All resistors have some inductance. If this is in reference
to one of the Pass designs, I wouldn't get too excited about it
unless your resistor looks like a big coil.
to one of the Pass designs, I wouldn't get too excited about it
unless your resistor looks like a big coil.
Resistor Quality
I have heard very good things about Painton resistors. Thorsten uses a green type in building some of his projects.
But the hard to solder leads make me suspect you have a steel lead material. I have found all the difficult to solder leads are steel. And this is a very bad material for audio. The permance and other magnetic properties make it suspect.
Try a magnet to check for this. I used to use some fantastic metal can capacitors that had the same problem. They were designed for high temperature and not quality. The steel lead material allows them to be welded instead of soldered. Perfect for hostile environment. To ease the soldering tin them a long time and the solder will finally stick.
To my tin ears the inductance of a ceramic case wirewound is less of a problem than ferric leads of a better quality resistor.
I always carry a magnet when diving around shopping the electronic surplus stores for parts.
George
I have heard very good things about Painton resistors. Thorsten uses a green type in building some of his projects.
But the hard to solder leads make me suspect you have a steel lead material. I have found all the difficult to solder leads are steel. And this is a very bad material for audio. The permance and other magnetic properties make it suspect.
Try a magnet to check for this. I used to use some fantastic metal can capacitors that had the same problem. They were designed for high temperature and not quality. The steel lead material allows them to be welded instead of soldered. Perfect for hostile environment. To ease the soldering tin them a long time and the solder will finally stick.
To my tin ears the inductance of a ceramic case wirewound is less of a problem than ferric leads of a better quality resistor.
I always carry a magnet when diving around shopping the electronic surplus stores for parts.
George
Re: Resistor Quality
You're aware that virtually all wirewound resistors (with the exception of some very low resistance types) use ferromagnetic material for the actual resistance wire and not just the leads, yes?
se
Panelhead said:
You're aware that virtually all wirewound resistors (with the exception of some very low resistance types) use ferromagnetic material for the actual resistance wire and not just the leads, yes?
se
Re: Re: Re: Resistor Quality
Nope, those too. They use nickel alloy wire, typically Nichrome. Nickel is ferromagnetic.
Pure copper just has too low a resistance to make it practical for use in wirewound resistors unless you need a resistor of just some tiny fraction of an ohm.
By the way, Mills is just down the street from me and I know the owners. 😀
se
Brett said:
Nope, those too. They use nickel alloy wire, typically Nichrome. Nickel is ferromagnetic.
Pure copper just has too low a resistance to make it practical for use in wirewound resistors unless you need a resistor of just some tiny fraction of an ohm.
By the way, Mills is just down the street from me and I know the owners. 😀
se
Re: Re: Re: Re: Resistor Quality
I've got some ~1mm diameter Nichrome 80 in my hot little hand and a speaker magnet in the other, and it appears to have no magnetic effect at all.Steve Eddy said:
Re: Re: Re: Re: Re: Resistor Quality
That's because the nickel is alloyed with chromium. Doesn't change the fact that nickel is ferromagnetic. Just as iron and cobalt are.
se
Circlotron said:I've got some ~1mm diameter Nichrome 80 in my hot little hand and a speaker magnet in the other, and it appears to have no magnetic effect at all.
That's because the nickel is alloyed with chromium. Doesn't change the fact that nickel is ferromagnetic. Just as iron and cobalt are.
se
Normally when you pass a current down a copper wire the magnetic field rotates around the axis of the wire. Imagine if you passed this same current down the length of a steel rod. Would the field surround the rod or would it be contained completely within it seeing it is ferrous. If it does stay inside it, does that mean there would be no mutual induction between our steel conductor and another (say, copper) conductor running parallel to it?
Re: Re: Re: Re: Re: Re: Resistor Quality
Ferromagnetism is a bulk property, if the spinels happen to be aligned then you have a magnetic moment, if not, you don't. It is likely that an annealed wire will not be antiferromagnetic so there could be a very small residual moment that circlortron didn't pick up with a magnet.
As far as choosing the better resistor which do we like best? A thin, highly uneven layer of vapor deposited metal or a piece of solid wire? Many seem to prefer the latter idea.Inductance can be minimized by counterotating windings.
In any case instead of worrying about kT-level noise due to coupling of ferromagnetic atoms in the resistor there are much more important issues like semiconductor noise, gnd noise, ripple noise, transformer buz etc.
Steve Eddy said:
Ferromagnetism is a bulk property, if the spinels happen to be aligned then you have a magnetic moment, if not, you don't. It is likely that an annealed wire will not be antiferromagnetic so there could be a very small residual moment that circlortron didn't pick up with a magnet.
As far as choosing the better resistor which do we like best? A thin, highly uneven layer of vapor deposited metal or a piece of solid wire? Many seem to prefer the latter idea.Inductance can be minimized by counterotating windings.
In any case instead of worrying about kT-level noise due to coupling of ferromagnetic atoms in the resistor there are much more important issues like semiconductor noise, gnd noise, ripple noise, transformer buz etc.
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