Resistors - brand and quality...

[Projectile]

Given the standard RoHS compliant 1/4w 1% metal film resistor, is there a difference between the quality of the actual components from brand to brand in actual use? Are higher quality resistors going to sound better, last longer, or have a lower failure rate?

The reason I ask is because I just got a pack of 2000 resistors off Ebay from Hong Kong for 13 bucks. I know, it sounded to good to be true, but a few people on the forum had ordered similar packs from this supplier with no negative comments, so I thought I'd give it a go. Turns out the resistors look pretty crappy. I didn't realize there was actual such a quality difference from supplier to supplier because all of the 1/4w metal film resistors I've seen look pretty much the same. Unlike caps, which are known to have a pretty broad sweep in terms of qualiity, I just figured a 1% metal film resistor is a 1% metal film resistor, so it wouldn't matter where I ordered them from. ...But these do indeed look pretty shabby. The normal smooth expoxy coating looks like cheap flat blue enamel paint or something, and the colored lines look like they were just sloppily applied with little quality control. I even think I can see metal ridges poking through the thin blue coating in some places. Not cool.

The tolerances measure fine with a multimeter, but needless to say, I'm a little nervous to use these in a project. They're probably fine, but they just look so crappy that it makes me uncomfortable using them.

What do you guys think? Are these things safe to use? Am I just being paranoid? Anyone else have any similar experiences? Anyone know where I can get better quality variety packs of resistors on the cheap?

Thanks.


 

[Nitefly182]

Good quality metal films are so cheap that its not really necessary to buy bargain packs off ebay IMO.

[Projectile]

Good quality metal films are so cheap that its not really necessary to buy bargain packs off ebay IMO.

Then please point me to a where I can buy them cheap without having to purchase every value individually. I'm tired of paying 20 cents apiece for them at small bear. should I just order 20 of every value from mouser of something? There must be an easier way.

For example, if I ordered the same 2000 resistors I got off ebay for 13 bucks, from mouser at .06 cents apiece, it would have cost $120; From small bear, $200!!! Before shipping!  That's quite a difference. Not to mention I would have to go through the catalog and select every single value individually instead of just buying one pack. I must spend a good five or ten minutes every time I order parts just scrolling through menus and making sure I have all of the values of resistors I need. It's freaking ridiculous! I want to just order them once and be done with it without spending $120! Come on, there has got to be something in between the crap off of ebay and the hassle and expense of ordering them from smallbear or mouser.

[Nitefly182]

Good quality metal films are so cheap that its not really necessary to buy bargain packs off ebay IMO.

Then please point me to a where I can buy them cheap without having to purchase every value individually. I'm tired of paying 20 cents apiece for them at small bear. should I just order 20 of every value from mouser of something? There must be an easier way.

20 of every value is the wrong way to go. I buy all my metal films from mouser in bags of 200 for $4 a bag. That can get expensive if you're stocking up on 100 values but if you buy a couple at a time youll be fine. Just search for xicon metal film resistors at mouser.com.

[Projectile]

20 of every value is the wrong way to go. I buy all my metal films from mouser in bags of 200 for $4 a bag. That can get expensive if you're stocking up on 100 values but if you buy a couple at a time youll be fine. Just search for xicon metal film resistors at mouser.com.

Yes, but that's completely impractical for a hobbiest like me. Why would I ever need 200 of one value of resistor? I just need a general selection, not bulk of one value.

[aziltz]

i bought in bulk off ebay and got great results.  took a month or so, from china but I got lots and lots of usable values for 8 bucks, and 8 bucks shipping.  probably 20 values at 50 each.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320331779875

[Nitefly182]

20 of every value is the wrong way to go. I buy all my metal films from mouser in bags of 200 for $4 a bag. That can get expensive if you're stocking up on 100 values but if you buy a couple at a time youll be fine. Just search for xicon metal film resistors at mouser.com.

Yes, but that's completely impractical for a hobbiest like me. Why would I ever need 200 of one value of resistor? I just need a general selection, not bulk of one value.

To me the advantage of buying at the first price break is that you wont have to buy them again for quite a while. I am very much a hobbiest but I know that buying what I need per project can add another 50% of the cost in covering shipping. As you build up your stock of parts you have to order less and less for new builds until you get to the point where building a pedal involves no part sourcing.

[Projectile]

Well, I got scammed! Scratched the epoxy coat off and they are CARBON FILM resitors underneath! M*ther F*cker! They are color banded as %1 tolerance. These are actual factory fakes! Total bullshit!

Stay away from "sureelectronics" on ebay!


You should scratch off the expoxy coating on one of your resistors aziltz just to make sure. I didn't even think anyone would go through the trouble of forgering metal film resistors, but apparently fakes do exist. Beware of ordering cheap components on ebay!

[biggy boy]

Hi I've purchased resistor sets from EBay also with no problem yet.
If it was me I would use those resistors you got.
We are building effect pedals not hospital life support systems or space shuttles.

Glen

[biggy boy]

 Just read your post above mine. Sorry to hear you didn't get what you ordered, that sucks, anyway I'd still use them.

Glen

Edit:
Just remembered you can dispute the purchase with Ebay and get your money back.

[MusicAudio]

Check out the resistor kits from Smallbear, for about $60 you can get 100 of every value a hobbyist will ever need. The leads are pretty flimsy, so they're not the best for breadboarding but they'll certainly do!

http://www.smallbearelec.com/Categories.bok?category=Resistors+-+1/4+Watt,+5%25+Carbon+Film:Carbon+Film+Resistor+Kits

[biggy boy]

Take a look at the picture in the link, what does yours look like. Which one?

http://www.sure-electronics.net/DC,IC%20chips/DC-RS013_2_b.jpg

Glen

[aziltz]

Well, I got scammed! Scratched the epoxy coat off and they are CARBON FILM resitors underneath! M*ther F*cker! They are color banded as %1 tolerance. These are actual factory fakes! Total bullsh*t!

Stay away from "sureelectronics" on ebay!


You should scratch off the expoxy coating on one of your resistors aziltz just to make sure. I didn't even think anyone would go through the trouble of forgering metal film resistors, but apparently fakes do exist. Beware of ordering cheap components on ebay!

thanks for the heads up.  i check and mine are the real deal.  sorry about the bad buy.  Hope you can get your money back.

[kurtlives]

20 of every value is the wrong way to go. I buy all my metal films from mouser in bags of 200 for $4 a bag. That can get expensive if you're stocking up on 100 values but if you buy a couple at a time youll be fine. Just search for xicon metal film resistors at mouser.com.

Yes, but that's completely impractical for a hobbiest like me. Why would I ever need 200 of one value of resistor? I just need a general selection, not bulk of one value.

I used to kinda think like that.

If you stick with the hobby though you wont think its too impractical imo. Ok I wouldn't go buying 200 5K6 resistors. I would buy your standard values, 470R, 1K, 4K7, 10K, 33k, 47K, 100K, 470K, 1M. Just today I was populating a PCB that need 12 10K resistor on it. Was using metal film for this project. Noticed I was getting low, damn just got 200 or so last year. Anyways over time you'll be glad you have those standard vales. Will last you some tome and you wont have to make little orders for cheap resistors.

[aziltz]

its a shame we have to deal with fake parts...

[Projectile]

Take a look at the picture in the link, what does yours look like. Which one?

http://www.sure-electronics.net/DC,IC%20chips/DC-RS013_2_b.jpg

Glen

That's the same picture I used for comparison. My resistors look exactly like the carbon film one on the left when I scratch away the epoxy. Their tolerances are worse than 1% as well. Just to be sure I compared the temperature stabiblty of a 1M ohm ebay resistor to a metal film from smallbear. When I held a soldering iron up to the surface while taking a measurement with a multimeter, the small bear resistor maintained a fairly stable reading, as should be expected from a metal film resistor. The ebay resistor on the other hand dropped about 6% in value when exposed to heat. This is very similar to the stability of a carbon film resistor from radioshack which I compared. It dropped around 4%.

These are obviously FAKE. I'm pretty shocked. Who in the hell makes forgeries of something as cheap as metal film resistors?!!!  I'm not even sure it's necessarily the ebay seller's fault as they were color coded as 1% tolerance resistors from the factory, which implies that they would be metal film. They were obviously manufactured this way, which just baffles me. Was it a mistake, a scam, or what??? This whole thing is pretty shady though, so I would advise people to stay away from this ebay seller "sureelectronics" altogether.  Beware, there are fake components floating around out there! This makes me more inclined to believe the seemingly ridiculous stories of people getting forged NOS 4558 chips.  

[Projectile]

Just curious, what's the difference between all of these different resistors available on mouser?

For instance, when I look up 1/4w 1Kohm 1% metal film Vishay/Dale resitors i get about 12 different part numbers. Their prices range dramatically from a few cents apiece to over a dollar, while from a cursory glance at the specs  they appear identical. I know I just want the cheap xicons for stompboxes, but I'm curious why there is such a wide difference in price between components of the same brand that appear to have nearly identical specifications. What's the deal?

[Nitefly182]

Just curious, what's the difference between all of these different resistors available on mouser?

For instance, when I look up 1/4w 1Kohm 1% metal film Vishay/Dale resitors i get about 12 different part numbers. Their prices range dramatically from a few cents apiece to over a dollar, while from a cursory glance at the specs  they appear identical. I know I just want the cheap xicons for stompboxes, but I'm curious why there is such a wide difference in price between components of the same brand that appear to have nearly identical specifications. What's the deal?

Some brands are more expensive than others or are mil-spec parts and stuff like that. Dale RN55s are awesome resistors but theyre expensive compared to xicons.

[tehfunk]

Just curious, what's the difference between all of these different resistors available on mouser?

For instance, when I look up 1/4w 1Kohm 1% metal film Vishay/Dale resitors i get about 12 different part numbers. Their prices range dramatically from a few cents apiece to over a dollar, while from a cursory glance at the specs  they appear identical. I know I just want the cheap xicons for stompboxes, but I'm curious why there is such a wide difference in price between components of the same brand that appear to have nearly identical specifications. What's the deal?

Some brands are more expensive than others or are mil-spec parts and stuff like that. Dale RN55s are awesome resistors but theyre expensive compared to xicons.

i was wondering, why are the rn55s so expensive... other than the fact that they look awesome!

[Nitefly182]

Just curious, what's the difference between all of these different resistors available on mouser?

For instance, when I look up 1/4w 1Kohm 1% metal film Vishay/Dale resitors i get about 12 different part numbers. Their prices range dramatically from a few cents apiece to over a dollar, while from a cursory glance at the specs  they appear identical. I know I just want the cheap xicons for stompboxes, but I'm curious why there is such a wide difference in price between components of the same brand that appear to have nearly identical specifications. What's the deal?

Some brands are more expensive than others or are mil-spec parts and stuff like that. Dale RN55s are awesome resistors but theyre expensive compared to xicons.

i was wondering, why are the rn55s so expensive... other than the fact that they look awesome!

They are precision resistors and the materials and production quantities are probably lower. I dont think theyre as massive a company as xicon for example. It may also be a percieved quality deal as well. More expensive for the sake of it. Many of their products are also super high tolerance. The CMF55 is their standard resistor and is meant to be close to milspec at a consumer price point. The actual RN55 is milspec and they are usually higher tolerance like .1 or .01%.