Czilla9000
10 Year Member. Still no custom title.
- Joined
- Feb 26, 2002
- Posts
- 2,249
- Likes
- 32
Who makes resistors THAT accurate. I know they are out there.....
Who makes 0.05% tolerance resistors?
- Thread starter Czilla9000
- Start date
tangent
Top Mall-Fi poster. The T in META42.
Formerly with Tangentsoft Parts Store
- Joined
- Sep 27, 2001
- Posts
- 5,970
- Likes
- 58
Why do you need them? If you're just trying to match two or more resistors to within 0.05% of each other, it's a lot cheaper to hand-match them from a batch of lower-precision resistors.
On average, you can find two 1% resistors within 0.05% with just 6.3 "draws" from a random sample. It's only 2.6 tries if you start with 0.1% resistors. If you think it's not worth the hassle, realize that 0.05% resistors often cost several dollars per resistor.
0.05% resistors are only valuable when you want a 1.000K resistor +/- 0.5 ohm. If instead you want two 1K resistors that are 0.05% of each other, and will be happy with two 1.009K +/- 0.5 ohm resistors, hand-matching is a much better idea.
(Do a search for resprob on Headwize if you want a copy of the program I used for these calculations.)
To answer your question, Welwyn makes these (RC series), and Vishay-Dale probably has several lines that go to 0.05%. Two lines I found without trouble are the PTF and PMA0207 series.
On average, you can find two 1% resistors within 0.05% with just 6.3 "draws" from a random sample. It's only 2.6 tries if you start with 0.1% resistors. If you think it's not worth the hassle, realize that 0.05% resistors often cost several dollars per resistor.
0.05% resistors are only valuable when you want a 1.000K resistor +/- 0.5 ohm. If instead you want two 1K resistors that are 0.05% of each other, and will be happy with two 1.009K +/- 0.5 ohm resistors, hand-matching is a much better idea.
(Do a search for resprob on Headwize if you want a copy of the program I used for these calculations.)
To answer your question, Welwyn makes these (RC series), and Vishay-Dale probably has several lines that go to 0.05%. Two lines I found without trouble are the PTF and PMA0207 series.
Czilla9000
10 Year Member. Still no custom title.
- Joined
- Feb 26, 2002
- Posts
- 2,249
- Likes
- 32
The schemetic I am working with has VERY VERY few resistors. Therefore I can afford to go "all out". What are the most precise resistors I can find? Where can I buy them.
Dreamslacker
500+ Head-Fier
- Joined
- Oct 7, 2002
- Posts
- 555
- Likes
- 10
Quote:
If you want the very best, I suggest Military Grade Vishay Bulk Metal Foil resistors. They're about US$5+ EACHthough.
| Originally posted by Czilla9000 The schemetic I am working with has VERY VERY few resistors. Therefore I can afford to go "all out". What are the most precise resistors I can find? Where can I buy them. |
If you want the very best, I suggest Military Grade Vishay Bulk Metal Foil resistors. They're about US$5+ EACHthough.
Czilla9000
10 Year Member. Still no custom title.
- Joined
- Feb 26, 2002
- Posts
- 2,249
- Likes
- 32
Interested....but where can I buy them?
Dreamslacker
500+ Head-Fier
- Joined
- Oct 7, 2002
- Posts
- 555
- Likes
- 10
Percy Audio has them. Not the military spec'ed but you won't need the Mil spec unless you plan to run them at high temperatures.
kerelybonto
doo-di-doo-di-dum doo-di-dum doo-di-doo-di-dum
- Joined
- May 6, 2002
- Posts
- 1,518
- Likes
- 10
I think Mouser carries the mil-spec Dales. I think THL Audio does too. Do a search on Google for 'dale resistors mil spec' and you'll find more stores that carry them. (I think the mil-spec resistors are marketed under the name 'Dale,' not 'Vishay Dale.')
kerely
kerely
Czilla9000
10 Year Member. Still no custom title.
- Joined
- Feb 26, 2002
- Posts
- 2,249
- Likes
- 32
THLAudio has the Bulk Metal Foil ones....but at only 0.1%....not at 0.05%.
At 0.1%...are they still the very best
At 0.1%...are they still the very best
Dreamslacker
500+ Head-Fier
- Joined
- Oct 7, 2002
- Posts
- 555
- Likes
- 10
Quote:
Metal foil resistors are supposed to give the lowest amount of noise. So they're reckoned to be like having no resistors in the amp at all. I reckon they're VSRJ resistors?
| Originally posted by Czilla9000 THLAudio has the Bulk Metal Foil ones....but at only 0.1%....not at 0.05%. At 0.1%...are they still the very best
|
Metal foil resistors are supposed to give the lowest amount of noise. So they're reckoned to be like having no resistors in the amp at all. I reckon they're VSRJ resistors?
carlo
Founder of 5 in heavy rotation
- Joined
- Oct 9, 2001
- Posts
- 1,270
- Likes
- 10
Czilla,
resistors are relatively cheap, so buy a few and experiment to see what sounds best for your application (if you have an open mind).
partsconnexion has some vishay/resistas (which apparently are different from roederstein resistas) at .05%, the closest matched resistors i've used are caddock mk132, with 2k consistently measuring to four digits.
best,
carlo.
resistors are relatively cheap, so buy a few and experiment to see what sounds best for your application (if you have an open mind).
partsconnexion has some vishay/resistas (which apparently are different from roederstein resistas) at .05%, the closest matched resistors i've used are caddock mk132, with 2k consistently measuring to four digits.
best,
carlo.
Users who are viewing this thread
