Chinese resistors on eBay - opinions?

[conleycd]

My resistor pack arrived this morning :

So, after several measurements I would say they are more like 5% tolerance or worse, which is OK.
EG- 6k8's measure from 6k58 to 6k65 ( from sample of about 15 of them ) I didn't find one that was
actually 6k8 at all.

The leads are very thin, I have used similar ones before with no issue but if you bend the lead 4-5 times
they will break off !
..... so don't do that

MM.

May be my math is wrong but 1% of 6800 ohms is +/- 680 ohms.  So a 1% tolerance would be 6120 to 7480.  I don't think 1% tolerance means within 1% variance of one another... I could be wrong and stand to be corrected.

CC

 

[Harpo]

May be my math is wrong ...

Sorry, yes. +/-1% of 6800 ohm is +/- 68 ohm 

 

[conleycd]

May be my math is wrong ...

Sorry, yes. +/-1% of 6800 ohm is +/- 68 ohm 

You know what,

As I was driving home from work today I started thinking 680 - is that right?  Wait, that's 10%.  I hope I can get home and correct it before I am known as world wide ass.

Too late.  I do appreciate the smile though.

Yes - 68 ohms is 1% of 6800.

CC

 

[bibleboy3]

I use these in my guitar amps all the time... they work good for me  ;D



Bill

 

[peranders]

I bought a kit of those resistors from china, like 50 of each value or something.
I think they are 5% carbon, as opposed to 1% metal film, as advertised.
They measure more than 1% off the nominal, and change value when heated, more than metal film supposed to...
Cheap though!
:

They are 5% metal film. I bought a kit on auction but I didn't see the 5% before I placed a bid. They look alright but the plastic bags falls apart if you'll touch them. I have never seen more fragile plastic bags. I think it's a better idea to buy real 1% resistors from Farnell. Then you'll know what to expect.

 

[leadpoisoning]

many years later - but i wanted to add to the findings. I purchased one of the 'el cheapo' packs of metal film resistors off an ebay seller who can be found (direct) here: http://www.sun-pec.com/home/metalfilm_121 (exactly the ones I bought I think)
(i assume it's the same seller because the page title and contents exactly matched the description of the ebay listing they had up)

A test trial of ten random resistors from a pack of 10Ks = meter is Tek TX1 (calibrated 2012)

09.91K    0.90%
10.00K    0.00%
10.01K    0.01%
10.02K    0.02%
09.86K    1.40%
10.05K    0.50%
10.01K    0.10%
10.01K    0.10%
10.02K    0.20%
09.98K    0.20%

I thought that was pretty great overall - what they don't give in precision the make up for in accuracy. (precision being consistency and accuracy being 'hitting the target')

Passed the heat test with FLYING colours (under the flame of a lighter - barely a change at all)

So anyway- there's someone out there who had good experiences.

I haven't tested them for noise yet however - but that's a pretty major undertaking...

 

[JohnRoberts]

Resistors are about the cheapest part... I wouldn't look there first to cut corners.

When I was a Peavey I had to accept switching to a cheaper vendor because of the millions of pieces involved. Of course you can always find parts that are too cheap to work (I've also found that samples can be better than production volumes from shady vendors. ) :.

JR

 

[emrr]

My only complaint is that no US supplier sells a reasonable resistor kit anymore, forcing those who need to buy the Chinese bags. 

 

[leadpoisoning]

There is NO indication there is ANY corner cutting going on - they seem to be AT least as good as american and european components from what I can tell. I am not sure that country of manufacture is any more a 'reliable' indicator. But as EMRR noted - I purchased them because I could get many values in one go. I wouldn't have minded paying perhaps $100 or $150 for resistors if I could do it as quickly. But I really didn't want to spend HOURS placing a single order... I posted my findings because they SEEM to be excellent parts - well above spec mostly.

Resistors are about the cheapest part... I wouldn't look there first to cut corners.

When I was a Peavey I had to accept switching to a cheaper vendor because of the millions of pieces involved. Of course you can always find parts that are too cheap to work (I've also found that samples can be better than production volumes from shady vendors. ) :.

JR

 

[Bowie]

There is NO indication there is ANY corner cutting going on - they seem to be AT least as good as american and european components from what I can tell. I am not sure that country of manufacture is any more a 'reliable' indicator. But as EMRR noted - I purchased them because I could get many values in one go. I wouldn't have minded paying perhaps $100 or $150 for resistors if I could do it as quickly. But I really didn't want to spend HOURS placing a single order... I posted my findings because they SEEM to be excellent parts - well above spec mostly.

Resistors are about the cheapest part... I wouldn't look there first to cut corners.

When I was a Peavey I had to accept switching to a cheaper vendor because of the millions of pieces involved. Of course you can always find parts that are too cheap to work (I've also found that samples can be better than production volumes from shady vendors. ) :.

JR

With all respects, I have to agree with John.  Simply checking resistance w/ a meter doesn't give me any idea how they will behave in-circuit, the consistency, noise, long-term reliability, etc.  For an extra dollar or two per piece of gear, I would rather go with something that I can trust, especially when it's a $1k - $2k piece of gear I'm building for a customer.  If it's taking you hours to shop resistors, then that's definitely a legitimate consideration.  I just can't find any good reason for someone like myself to go cheap on resistors and it will almost undoubtedly cost me more in the long run.

 

[PRR]

> found that samples can be better than production volumes

I musta told this?

I worked in a newspaper press, free weekly shopper, wrapping and stacking the output. $2/hour.  When you start a large pulp-paper press, the ink is skippy and the folds run through the pages. Two pressmen run the press slow, troweling the ink and adjusting the pressure and spacing. We threw these in the dumpster. When the copies were "good enough" they ran the press up to 75% speed, and we stacked them for newsstand delivery. The junior pressman disappeared into the office. The HMFIC pressman ran around the press trimming and shimming. Then he'd call "Samples, 200!" We wrapped and stacked those extra neat and set the skid aside. Then he'd turn the speed to 100% and go in the office to play cards. If we saw the web rip or noticed blank pages, we'd fetch him, otherwise he didn't care.

The samples, of course, went to the guy who sold the ads. He showed the ad-buyers that their ad ran, it looked "beautiful", and took the ad-order for the next week.

Spinning resistors in hydrocarbon soot isn't much different. You got a startup where the pot is cold and the gas is rich, and then vice versa. HMFIC trims this and that until it is as good as it's gonna get. Here is the time to yell "Samples!" and put those aside for Mr Roberts' approval. Then crank the speed to the max and go throw the dice until something goes so wrong that even the $2/hour(day?) workers notice.

 

[CJ]

they want your business over there, bought 10,000 toroids, told them we wanted a minimum of 10 Henries,

well, they took turns off each coil til they were exactly 10 henries, custom matched each one, totally unnecessary, 

did not charge extra, kind of sad,  ???

fixed the communiaction problem, so they were happy to just wind 2000 turns with no trimming,

 

[CJ]

hmmm, one more thing to check besides resistance value,

temp coef  garnered the idea from this>

http://www.lynx.bc.ca/~jc/TSL122.html

note: after further reading, the PC Board might be the problem,

still a good read,

 

[Whoops]

Just to let you know that last year I bought these 2 assortment packs of resistors from ebay and I'm more than happy with them, resistors measured in 1% tolerance range with my Fluke multimeter

Seller: ic.touch-uk
country:  UK
http://www.ebay.co.uk/itm/50value-500pcs-1W-Metal-Film-Resistor-1-Assortment-Kit-UK-/181762509501?hash=item2a51e3cabd


Seller: delhanway2009
Country: HK
http://www.ebay.co.uk/itm/640-Pcs-64-Values-1R-10MR-1-4w-1-Metal-Film-Resistor-Kit-Assortment-Pack-Mix-/300925197516?hash=item46108a1ccc

 

[Anthon]

I bought several kits, containing thousands of resistors from Chinese vendors, 1/4W 1% for my modular synthesizer project.
I measure every resistor before I mount it on PCB, and after assembling a dozen of PCBs I haven't found any resistor that was faulty. I didn't bother checking for tolerance, since most resistors needed to be 5% - but where I needed 1%, didn't found any that weren't within tolerance.

The paint comes off easily (from 1 particular kit) - but it's the same with Solen Fast caps.
Leads are a bit thinner, but it's not a big deal.

I think they use same stuff for consumer electronics - and resistors rarely fail in these devices.

I think it is well worth the money for most DIY work. They are cheap, and you save a lot time - because you always have all the values you need at hand. No need to place an order, just because you miss 1 resistor - especially useful when you work on a huge project, like a modular synth or if you are building something out of scrap parts.

For high-end stuff I would use a brand though. Not because there are some differences that I noticed, but because you spend so much money on other components/planning/assembling, that you might just as well spend some extra on quality resistors.
I would still use them for prototyping/experimenting.

I recently ordered 1/2W 1W 2W and 5W kits, because I'm doing more tube stuff lately.

 

[john12ax7]

Even high quality resistors are fairly cheap these days, so I don't see it being worth the trouble trying to save a few bucks.

Plus there is also a difference in performance between various brands even when they are all metal film 1%.

So my 2c is just stick with known quality brands from reputable vendors.