Metal Foil Resistors

[arnach]

While I enjoy doing DIY projects on the side, I do run a small audio company. We are in the prototyping stage of a preamplifier and are considering various forms of resistors:

Of course, most of you will know these two:

Caddock TF020
Vishay S102/VTA56

But have you heard of these:

Calley Spears
Isotek (isotekcrp)
Alpha (alpha-amer)
KOA (koaspeer)
Wilbrecht (wilbrecht)

Since I am concerned with subjective qualities, I'm wondering if any of you have any experiences with these manufacturers and their products? I am considering sampling the Wilbrecht MAQ/MAN metal foils - 2.5 to 5 ppm.

Thanks,

Aaron Finley
arnach5@hotmail.com

 

[AudioFreak]

depending on the final price point, you might also consider tantalum resistors.... the better ones are probably the most stable i have come across quoting 0.5% tolerance and <1ppm thermal drift.... only major trouble is that they are very hard to source and cost a mint.

 

[arnach]

Hmm

The availability of tantalum resistors cannot be guaranteed.

-- Aaron

 

[gnomus]

Try Vishay Nude Bulk Metal Foil made for audio applications.
These are not the same as regular S102. Specs that make tantalums look like they come from the stone age. They have no coloration. I priced 221 ohms for my SOZ. Recent(1/2002) prices for one at .005% $10.50, .01% $7.51, .05% $7.01. Price can vary depending upon resistance. You can buy these from www.texascomponents.com there part number TX2352.

Manufacturers most likely get better deals.

I have used tantalums too. Those would be my second choice. Audio Note may still have these. And since they like them a lot they will most likely find a way to continue production.

The SOZ has so few parts you can get a little erotic(whoops exotic).

 

[arnach]

What

Those prices are incredibly inexpensive for that tolerance. Normally for small quantities in the beginning I see around $10 for a 1% tolerance resistor, going up to $40/ea for .01 or .001%(!).. If your getting that tight a tolerance for $10/ea your getting quite a deal.

Thanks,

Aaron

 

[tvi]

If you are considering surface mount you might want to try <a href="http://www.venkel.com/pdf/MELF_TFCR.pdf">VENKELs MELF</a> resistors, they are a Tantalum Alloy thin film avalable in 1/5 1/4 and 1W

It on my list of "Get Samples From" hopefully
<hr width="95%" align=center>
<a href="http://www.rikendengu.co.jp/audio.html">Riken Audio resistors</a>


Regards
James