Time to pick the brains of the largest audio oracle on the planet!
I'm looking for some non-magnectic resistors at sensible prices (not mad audio ones!) of reasonable precicison, along the lines of the Vishay-Dale RN60.
I'd also like the option to try some SMD for the project, but choice would be limited to 1/2W rated devices.
So, two questions: -
1. Is there anywhere in the UK / Europe I can get the Vishay's from, or is the US the only option.
2. Does anyone know of any SMD non-magnetic resistors of 1% precision, with good tempco and low noise (i.e. similar to Visahay)
I can look up the specs, but every SMD resistor I've bought so far is magnetic 🙁
Thanks, and please don't let this descend into a debate on the audibility of magnetic components 😉
Andy.
I'm looking for some non-magnectic resistors at sensible prices (not mad audio ones!) of reasonable precicison, along the lines of the Vishay-Dale RN60.
I'd also like the option to try some SMD for the project, but choice would be limited to 1/2W rated devices.
So, two questions: -
1. Is there anywhere in the UK / Europe I can get the Vishay's from, or is the US the only option.
2. Does anyone know of any SMD non-magnetic resistors of 1% precision, with good tempco and low noise (i.e. similar to Visahay)
I can look up the specs, but every SMD resistor I've bought so far is magnetic 🙁
Thanks, and please don't let this descend into a debate on the audibility of magnetic components 😉
Andy.
ALW said:
You're not likely to find any. Virtually all SMD resistors now have a nickel barrier plating on their terminals to prevent leaching during the soldering process. I've looked and haven't found any yet which don't incorporate a nickel barrier.
se
Nickel Barrier
Thanks Steve,
It looks like I may have to just try some standard ones then, and see if the other benefits outweigh the magnetic issue.
Can't believe I spelt magnetic wrong in the title
Thanks Steve,
It looks like I may have to just try some standard ones then, and see if the other benefits outweigh the magnetic issue.
Can't believe I spelt magnetic wrong in the title
Andy, can't you try using "magnetic" resistors? I gather you listen to CD and every CD player has magnetic resistors so I'll guess this parameter isn't crusial?
I have magnetized a screwdriver and the 0805 resistor get lifted by a rather weak force.
I have magnetized a screwdriver and the 0805 resistor get lifted by a rather weak force.
An aquaintance of mine would always carry a magnet to the electronics store to test the components before purchasing. I think that is a rather good idea!
Get the guys to whip out their stuff, then refuse to pay if they respond to the magnet 🙂
Or go the easy route, look for Ni plating like Steve suggested.
(unrelated: You mention SMD's, and they do have advantages. However, some of them are so small that they rather easily become thermally modulated with the audio signal. Worth bearing in mind 🙂)
Petter
Get the guys to whip out their stuff, then refuse to pay if they respond to the magnet 🙂
Or go the easy route, look for Ni plating like Steve suggested.
(unrelated: You mention SMD's, and they do have advantages. However, some of them are so small that they rather easily become thermally modulated with the audio signal. Worth bearing in mind 🙂)
Petter
Re: Re: SMD non-magentic resistors
How about Macrochip series from Ohmite? Not a lot of values but according to specs at least I could easily be made to believe that they are not magnetic.
Steve Eddy said:
How about Macrochip series from Ohmite? Not a lot of values but according to specs at least I could easily be made to believe that they are not magnetic.
Re: Re: Re: SMD non-magentic resistors
Well you'd have to check with Ohmite. When they refer to termination, they're only referring to the outer plating. There's also the lead material itself, then whatever plating may be over that and then any final plating.
se
UrSv said:
Well you'd have to check with Ohmite. When they refer to termination, they're only referring to the outer plating. There's also the lead material itself, then whatever plating may be over that and then any final plating.
se
SRT Resistor Technology
<a href="http://www.srt-restech.de/engl/downloads_e/chreng_neu.pdf">Chip-Resistors for Conductive Glueing PtAg-Contacts (non-magnetic)</a> They can also be soldered
or <a href="http://new.vishay.com/docs/20011/dcrcwhr.pdf">Vishay Thick films</a> available with Silver Palladium contacts
Both are only available to 1/4 watt
Hope this helps
Regards
James
<a href="http://www.srt-restech.de/engl/downloads_e/chreng_neu.pdf">Chip-Resistors for Conductive Glueing PtAg-Contacts (non-magnetic)</a> They can also be soldered
or <a href="http://new.vishay.com/docs/20011/dcrcwhr.pdf">Vishay Thick films</a> available with Silver Palladium contacts
Both are only available to 1/4 watt
Hope this helps
Regards
James
OK, let's read the fine print...
I agree with Steve E.; I don't think any SMT
resistor is made w/o a nickel layer. The
Ohmite mentions PdAg (Palladium/Silver)
terminations. Things like PdAg and PdAu
are becoming the platings of choice for
politically correct "lead-free" components that
will be used in politically correct "lead-free"
solder processes. But all that I know of are
"NiPdAg" or "NiPdAu".
The SRT resistors cited claim to be "non
magnetic", but I can't believe there isn't
nickel there somewhere. If so this is the
only exception I know of.
The Vishay resistors referenced clearly
state that they have a Nickel barrier layer.
-----
Speaking of SMT resistors, can anyone tell me
why audiophiles seem perfectly content to use
"thick film" resistors. These are essentially
the same as what we used to call "carbon film"
in through-hole resistors. I've not seen more
than one or two mentions of the use of "thin
film" SMT resistors. Comments?
I agree with Steve E.; I don't think any SMT
resistor is made w/o a nickel layer. The
Ohmite mentions PdAg (Palladium/Silver)
terminations. Things like PdAg and PdAu
are becoming the platings of choice for
politically correct "lead-free" components that
will be used in politically correct "lead-free"
solder processes. But all that I know of are
"NiPdAg" or "NiPdAu".
The SRT resistors cited claim to be "non
magnetic", but I can't believe there isn't
nickel there somewhere. If so this is the
only exception I know of.
The Vishay resistors referenced clearly
state that they have a Nickel barrier layer.
-----
Speaking of SMT resistors, can anyone tell me
why audiophiles seem perfectly content to use
"thick film" resistors. These are essentially
the same as what we used to call "carbon film"
in through-hole resistors. I've not seen more
than one or two mentions of the use of "thin
film" SMT resistors. Comments?
Thick versus thin film.
I cannot tell you why, but audiophiles prefer thick film -- period. New old stock carbon composition resistors are the ultimate in "thickness" and command good prices.
I believe thick film resistors will have lower inductance (seems so from theory anyway), and possible less chance of hot-spotting (i.e modulation by audio signal).
Perhaps some of the other experts will have better explanations.
Petter
I cannot tell you why, but audiophiles prefer thick film -- period. New old stock carbon composition resistors are the ultimate in "thickness" and command good prices.
I believe thick film resistors will have lower inductance (seems so from theory anyway), and possible less chance of hot-spotting (i.e modulation by audio signal).
Perhaps some of the other experts will have better explanations.
Petter
Does anyone know...
...what DACT are using, I have a DACT attenuator, and the SMD resistors used, I've discovered today, are non-magnetic 🙂
Andy.
...what DACT are using, I have a DACT attenuator, and the SMD resistors used, I've discovered today, are non-magnetic 🙂
Andy.
Petter,
But go look at the data sheets. For example, Dale TNPW (thin film)
vs. Dale CRCW (thick film). The thin film is a far more precise
component with much better specs and performance
than the thick film.
In general, in through-hole parts, "metal film" resistors (or
better -- like Vishay) are preferred to "carbon film", except among
the tube diehards (no comment). So why would it be the
opposite for SMT resistors?
Compare the CRCW vs. TNPW. TNPW has lower noise.
TNPW has lower nonlinearity. HF performance is essentially
the same (inductance is largely a function of package size).
So, again do you say thick film is "better"?
Methinks people don't know about thin films and/or can't
easily obtain them.
Andy, it would be interesting to know what DACT uses.
But go look at the data sheets. For example, Dale TNPW (thin film)
vs. Dale CRCW (thick film). The thin film is a far more precise
component with much better specs and performance
than the thick film.
In general, in through-hole parts, "metal film" resistors (or
better -- like Vishay) are preferred to "carbon film", except among
the tube diehards (no comment). So why would it be the
opposite for SMT resistors?
Compare the CRCW vs. TNPW. TNPW has lower noise.
TNPW has lower nonlinearity. HF performance is essentially
the same (inductance is largely a function of package size).
So, again do you say thick film is "better"?
Methinks people don't know about thin films and/or can't
easily obtain them.
Andy, it would be interesting to know what DACT uses.
BrianL
I am not able to provide proof of what is best, however I will say that the resistor which is probably considered the "best" in audio by the "most people" is the Vishay bulk metal foil (like really thick film?) 102 series. Their theoretical "evidence" is that of rise time. I still believe inductance is also a function of how the material is set up (i.e a large diameter conductor will have lower inductance than a tube of the same diameter).
Now that I think about it, I have seen Vishay bulk metal foil units in SMD: Types SMR1D (.25W, 6mm length) and SMR3D (.6W and 7.3mm length). They are as dear as the S102J series, but have the same specs with the same 1nS rise time. In the datasheet, I found no mention of barrier material though only a reference to "7 technical reasons to buy bulk metal foil" which ended up with one million hits on the totally crummy Vishay website. Yuck!
(update: I found the file, and it showed the resistor having a path which reduced inductance (serpentine pattern) and decreased capacitance (many series capacitors). It also referred to resistive metal having much lower noise than a composition. I find this believable)
I much prefer throughole units myself from a DIY point of view.
Petter
PS: I was referring to Carbon composition, not Carbon film .... not that I use any of those either ...
I am not able to provide proof of what is best, however I will say that the resistor which is probably considered the "best" in audio by the "most people" is the Vishay bulk metal foil (like really thick film?) 102 series. Their theoretical "evidence" is that of rise time. I still believe inductance is also a function of how the material is set up (i.e a large diameter conductor will have lower inductance than a tube of the same diameter).
Now that I think about it, I have seen Vishay bulk metal foil units in SMD: Types SMR1D (.25W, 6mm length) and SMR3D (.6W and 7.3mm length). They are as dear as the S102J series, but have the same specs with the same 1nS rise time. In the datasheet, I found no mention of barrier material though only a reference to "7 technical reasons to buy bulk metal foil" which ended up with one million hits on the totally crummy Vishay website. Yuck!
(update: I found the file, and it showed the resistor having a path which reduced inductance (serpentine pattern) and decreased capacitance (many series capacitors). It also referred to resistive metal having much lower noise than a composition. I find this believable)
I much prefer throughole units myself from a DIY point of view.
Petter
PS: I was referring to Carbon composition, not Carbon film .... not that I use any of those either ...
Vishay -- that is REAL Vishay bulk metal -- is the cat's meow.
Few people realize that Texas Components is a Vishay
licensee -- they trim resistors to spec and then package them.
I hear that these guys are much better to do business with
than Vishay.
Few people realize that Texas Components is a Vishay
licensee -- they trim resistors to spec and then package them.
I hear that these guys are much better to do business with
than Vishay.
A couple of Susumu SSM's metal-film SMD resistor series are available in +/-5ppm tempco and +/-0.1% precision. The RN73 is a 1/10W part, RR1632 is a 1/8W part, and the RR2632 is a 1/4W part. And the cost should be considerably less than for Vishay or Alpha's bulk-metal-foil components.
You will need Japanese fonts to read this, but here is the link for a PDF of Susumu's high-precision series of SMD resistors.
http://www.susumu.co.jp/pdf/j06.pdf
hth, jonathan carr
You will need Japanese fonts to read this, but here is the link for a PDF of Susumu's high-precision series of SMD resistors.
http://www.susumu.co.jp/pdf/j06.pdf
hth, jonathan carr
jcarr said:
Here's the english datasheet:
http://rocky.digikey.com/WebLib/Susumu/Web Data/RR Series Thin Film Chip Resistors.pdf
I use these, mainly because Digi-Key carries them.
JWB: Our respective datasheets are not for equivalent-grade resistors. The pdf that you linked shows the tolerance as +/-0.5% and the best tempco as +/-25ppm, while the pdf that I linked has the tolerance as +/-0.1% and the best tempco as +/-5ppm (which begins to approach Vishay-Alpha specifications, but is still appreciably worse. The tempco for a Vishay or Alpha bulk-metal foil will be less than 1ppm.)
IMO, the English datasheet that you should be downloading is here:
http://www.susumu.co.jp/english/pdf/e06.pdf
BTW, may I ask what Digi-Key's prices were for the +/-0.5% +/-25ppm parts?
best, jonathan carr
IMO, the English datasheet that you should be downloading is here:
http://www.susumu.co.jp/english/pdf/e06.pdf
BTW, may I ask what Digi-Key's prices were for the +/-0.5% +/-25ppm parts?
best, jonathan carr
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