Recommended Brands for parts (caps, resistors, etc)

[requim]

Since I'm new to this I've bought an assortment of parts primarily from Fry's Electronics in the form of Velleman caps, resistors, etc.  In addition I purchased parts directly from Agilent to repair a DC power supply and I've purchased some stuff from Digi-Key for a Harman/Kardon receiver I'm fixing as well as the previously mentioned power supply.

Ordering the parts from Agilent for the PSU became a no-brainer.  Not because I wanted to pay more, but because it resolved the issue of me having to find the recommended part.

At the moment my method of finding and buying components for specific fixes is to find the component that generally is the most expensive that matches at least the minimum specs required.  Case in point being a cap that was -10+100 and I picked a 5% part to replace it and instead of 105C I replaced it with a 125C part.  With caps I've been trying to get low ESR parts because I have been hoping/assuming that it can't hurt the overall circuit design.  There are numerous other specs that are meaningless to me. But I digress.

How am I supposed to know what the good brands are and what the bad brands are?  The caps I purchased for the PSU were from Panasonic.  The ceramic caps I ordered today for the HK receiver are TDK.  The fusible resistors are from Vishay.  I have no idea whether any of them are good supplies, other than the prices were on the higher end for the parts compared to the others.

Does the quality of a given component from a given vendor/supplier/source vary over time?  Is there a place I can go to to see what the good vendors for a specific product are?  It's not like these websites are like Amazon where people post reviews and give stars to the specific components.  Besides I'd imagine it's hard to know until later when the components start failing.

Is there some sort of generalized list of associates:

ie company X, Y and Z are really good for ceramic caps
   company A, B, and C are really good for resistors
   etc ...

Anyway.. Advice? 

[requim]

bump

[Simon]

why the bump. if you have no replies it is probably because no one has any information to give. the usualy course of action is to trust the supplier (not the manufacturer) on passives and decretes and to trust the manufacturers for IC's

[requim]

If that is the case, then who are the trusted suppliers?  I'm sure Digi-Key is one of them.. who are others?  I've placed orders with Mouser and Newark, both of which I believe make that list.

[Simon]

Well in the UK, Farnell, RS (radio spares), digi-key (if you have more money than sense), Rapid online are pretty good.

[requim]

How about within the US?  I have been buying from Digi-Key primarily because a very large previous company I worked ordered hundreds of millions of dollars in parts from them every year (if not billions of dollars) so it was a company I was familiar with.  Their shipping is pretty fast and the rates to my inexperienced eye seem reasonable.  I've done minor price comparisons between them and Mouser and Newark and they're all about the same. 

I know there used to be some sort of website where you could enter a part or parts and it would tell you where you could get them for the best price.  Does such a site still exist and if so what is it?

[Simon]

mouser is another reliable source, In the UK digi key is quite expensive although i gather this is not the case in the US

[baljemmett]

I know there used to be some sort of website where you could enter a part or parts and it would tell you where you could get them for the best price.  Does such a site still exist and if so what is it?

There are at least two; one is Octopart, and the other is findchips (whose sponsorship banner and search box should appear at the top of this forum -- obviously this is working well to raise awareness )

[requim]

Thanks for the tip.  I tend to ignore all ads so I hadn't even noticed the ones on this site for findparts.  I'll have to give them a try.

[david77]

I'd say as long as you get your parts from a reputable source there shouldn't be too much trouble.

Of course if you order your stuff off ebay or from some shady source in China you may well be unlucky enough to get crap.

[metalphreak]

Ebay can be good for some parts (especially those used in mass volume in chinese products...). Things like LEDs are way cheaper than typical electronics retailers. But you run the risk of fake or out-of-spec parts and a lot do not specify part numbers. Good for hobbyists, not great for production products.

As Dave showed in one of his videos, you can still get faulty or incorrect parts from reputable places. Mistakes do still happen. The high precision resistors he bought for uCurrent boards were well out of spec. The difference is, Digikey and others will help you out when things go wrong.

[Flavour Flave]

I've heard that WIMA are meant to make good quality capacitors somewhere, correct me if I'm wrong.

http://www.wima.de/en_index.php

I think Rubycon and Panasonic make good caps as well.

[alm]

As Dave showed in one of his videos, you can still get faulty or incorrect parts from reputable places. Mistakes do still happen.

Absolutely, but 'mistakes' happen much more often with shady Ebay sellers. There's a fairly significant probability that 1% metal film resistors are repainted carbon film, for example.

I think Rubycon and Panasonic make good caps as well.

They make good caps, but choosing a Panasonic high-ESR cap in a SMPS application with high pulse currents can make the cap die soon. Also be wary of fakes, I would be careful buying large expensive electrolytics from Ebay.

[FenderBender]

I'm a bit of a component quality freak. One of the main reasons I like making stuff myself is because I can choose excellent quality components that you do not typically find in mass produced electronics.

Caps: Electrolytics are the most important to get right here. They are most likely to die. Tantalum after that. Film after that. Ceramics are very hard to kill but still get good ones.

Electrolytics: Nichicon, Panasonic, United Chemi-con, Rubycon, Cornell Dubilier, Elna, Kemet, Xicon
Tantalum: Kemet, Vishay, AVX
Film: Wima, Panasonic, Cornell Dubilier, Kemet
Ceramic: Kemet, Vishay, AVX, TDK, Murata

Resistors: I don't think brand really matters nearly as much for resistors, but here are just some good names:

Vishay/Dale, Xicon, KOA, Panasonic, Yageo, Arcol

Inductors: Also not as vital. Look at specifications and try to get the best you can. Some brands:

JW Miller (Bourns), Murata, Cooper Bussman, Pulse, Panasonic, API

Semiconductors: You probably know the big names by now. Just for reference.

Texas Instruments, ST Microelectronics, National Semi(Now TI), ON Semi, Fairchild Semi, Freescale Semi, NXP Semi, Analog Devices, Maxim, Diodes Inc., Avago, Vishay

[BravoV]

Caps: Electrolytics are the most important to get right here. They are most likely to die. Tantalum after that. Film after that. Ceramics are very hard to kill but still get good ones.

This is interesting, just asking, how a film type cap can be easily killed compared to ceramic ? Cause all this time I thought film is the toughest one ?

[requim]

@FenderBender - Thanks.  I'm going to have to bookmark/save that list.  It should help me in the future.  Any idea about TDK for ceramic caps?  I purchased some from them for the receiver because they appeared to be the best and were a bit pricey compared to the others.

[FenderBender]

Caps: Electrolytics are the most important to get right here. They are most likely to die. Tantalum after that. Film after that. Ceramics are very hard to kill but still get good ones.

This is interesting, just asking, how a film type cap can be easily killed compared to ceramic ? Cause all this time I thought film is the toughest one ?

If used correctly, neither should really have an issue at all. There's no liquid to dry up or anything of that matter, but certain types of film caps, notably polyester are not as tolerant of high voltages and overload conditions. They are also typically carry very high temperature ratings. Typical film caps will be between 80-125*C (plastics melt) while most ceramics and MLCCs are rated for 150*C+ in many instances. Really they are quite similar, and I guess I shouldn't have made such a distinction, but there is a slight difference.

[FenderBender]

@FenderBender - Thanks.  I'm going to have to bookmark/save that list.  It should help me in the future.  Any idea about TDK for ceramic caps?  I purchased some from them for the receiver because they appeared to be the best and were a bit pricey compared to the others.

TDK is a reputable brand. They are good.

When you are buying ceramics (MLCCs), you have to pay attention to not only capacitance and voltage rating, but also the dielectric used and the temperature coefficient.

A better temp coefficient means better stability over the lifetime of the part, less losses, and less noise. The best you can get is C0G (aka NP0). (Those are classified as Class I capacitors. Pretty much mission critical stuff only). After that, you have to step down to Class II, which are still typically fine for most things. I tend to use X7R because they are not nearly as expensive as C0G but have good performance overall.

This is a good reference: http://www.radio-electronics.com/info/data/capacitor/ceramic-capacitor.php

If you look at the Class II chart, you can see that the "worst" cap would theoretically be Z2V and the best X7D. However, you actually will rarely see either of those temp coefficients. The most common ones are: Z5U, Y5V, X7R, C0G

Hope this helped.

[requim]

I just looked it up and it looks like the TDK caps I bought are rated C0G, so I guess I did well.  With any luck they won't give me problems.  That would explain the higher prices on them.

[FenderBender]

At lower capacitances the price is not that much different. But that's more for the pF range. On the nF/uF range, the prices can be A LOT higher for a C0G part.

[robrenz]

Once you know the part# either manufacturer or distributor, plug it into the findchips bar at the top of this page.  you will instantly see who has it in stock and who is the cheapest.  I have found Allied electronics in the US to usually be the lowest prices and they give very good service.

[requim]

As it turns out according to findchips digikey had the parts for the lowest price.  Mouser was cheaper if I was buying in quantities of 100+, but was more expensive in quantities < 50.  But that's not to say if I used a different manufacturer that my results couldn't have changed.  Overall I'm not too worried.  All told, excluding the extras I spent about 3.50 + tax and shipping.

In the future I'll at least reference findchips or octopart.  Between the two sites I prefer octopart.  Their search results present the results in manner that makes analysis/selection much faster.

[nukie]

I have seen film caps die and these are brand name, they are used in high temperature industrial machines. Even worst, they still hold capacity when broken so its not possible to test with a capacitance meter or ESR meter.  It's rare to find broken ceramic.

[requim]

@nukie - this may seem a foolish question, but how do you know the cap is dead if it still holds capacity and the esr is within range?

[nukie]

you use the scope and see if its doing the filtering properly. in my case it was a MKP mains filtering film cap.