Don't bother with NTE replacement parts!!

[compuwade]

About a year ago I found runoffgroove.com and I built a condor and fell in love with it. As a result I decide to try the Thor. The only problem was that I couldn't get the J201 or the 2n5457 here locally. However, after doing some research I found that I could get the NTE replacement parts at my local Fry's. So I bought the NTE457 and the NTE458 which are the replacements for the 2n5457 and the J201. I built the Thor and boxed it up, but I hated it. It sounded like crap!! Several months later I purchased the original parts from mouser and built several other projects. Last night I was thinking about building another project, but I was running out of pots, so I started looking at my old projects that I don't use and I came across the Thor. I thought about it for a while and decided to replace the NTE parts with the original parts before I completely gave up on it. And holy crap, This thing was a whole new beast!! It sounded great! The only changes I made were to the fets. Anyway, to make a long story a little shorter, don't buy these over priced parts from Fry's. They may work, but your sound will be compromised and you may end up tearing something apart without ever really knowing it's real potential.
The only luck I've had with the NTE parts is with the op amps. And that's only because the ones that I purchased were the original parts with the NTE part number stamped on them. You could see the TI part numbers underneath. 

Anyway, I hope this info is useful to someone.

-Wade

[Gus]

You are working with Jfets.  Jfets can vary in specs in the same part number.  Some circuits are designed for a Jfet with in a certain IDSS, Vgsoff, etc range.  The NTEs might work fine in another circuit or with an adjustment(s) to the circuit.

[Mark Hammer]

NTE parts are "good enough" replacements.  As with any electronic component however, the acceptability will depend on what you are substituting for and what the minimum criteria are.  Bear in mind that the vast majority of electronic substitutions are for components that have nothing whatsoever to do with audio or audible changes.

That being said, I'm with you 100% on the assertion that one cannot always be guaranteed a desirable outcome merely by flipping through the coss-reference and finding out that NTE number whatever is a "sub" for some other component.  Sometimes you get lucky, and the component is so specific that there could be only one set of criteria to conform to.  For example, NTE used to carry an MN3007 equivalent.  There is only one way to make those, so using one would automatically get you the "same thing" as an MN3007.  Transistors are more broadly applicable, though, and may have parameters that meet one set of needs in one context but not another.  Note that this is also true whether you buy an NTE replacement, or happen to flip through a 70's style HEP (Motorola) cross-reference or any of the other transistor cross-references that one could buy in the good old days, and identify a supposed "replacement"' there too.  I can look up an AC128 in my HEP and SAM's cross-references, and they will list "replacement" devices for me.  Will scoring two of those nail me a great Fuzz Face?  Not on your life.

[compuwade]

You are working with Jfets.  Jfets can vary in specs in the same part number.  Some circuits are designed for a Jfet with in a certain IDSS, Vgsoff, etc range.  The NTEs might work fine in another circuit or with an adjustment(s) to the circuit.

I agree that they may work with other circuits or with a few changes to a circuit. But my main point is that the majority of inexperienced builders are going to buy these parts thinking that they are what they need to complete the curcuit. But when they put the project together and find that it sounds bad, they will almost always blame the design before they blame the parts they purchased. I just wanted to voice my experience with the NTE parts so that there is some sort of info for a reference in case someone has the same problem.

I have purchased NTE power transistors for a subwoofer with good results. But to me, it's not worth the money or the time to even bother with these parts.

[Ibanezfoo]

I too have had bad luck with NTE parts.  Now its much easier just to pick up piles of Fairchild/TI/whatever else on ebay for dirt cheap.

[JKowalski]

I once bought four different 9V regulators (NTE) from fry's and they all read something like 11VDC out, loaded or unloaded. I never found out what the issue was, so I assume the parts were somehow faulty...

[Cliff Schecht]

NTE simply buys up bulk parts and relabels them with their number. They will buy literally anything so long as they can erase the original label, put on their own stupid numbering system and upcharge the crap out everything. I'm sure they are making a killing selling parts that were swept off the floor (not kidding) and probably failed the original manufacturers quality testing. The best thing to do is to learn to order off of a large distributor like Mouser or Digikey, really whoever is closest to your shipping address. In Austin AND Lubbock, I can order parts off of Mouser anytime before 7:00 PM and have them at my doorstep by 1:00 PM the next day. I just make sure to order enough stuff to justify a $5-$7 shipping charge.

[xdissent]

FETs are notoriously finnicky. Samples can vary wildly even if they are from the same manufacturer. That's why you'll see specs giving ranges of values for JFET I_DS often spanning 5ma or more. This is why they're almost never used as current sources without a trimmer, and even then the tempco will play a major role in actual I_DS. In other configurations the tolerances matter less, but the point is that the argument is not one of quality, just performance within a given circuit. The originals you have are not "better", they're just closer to what the designer probably used when setting the operating conditions. Add more active devices to the circuit, and the differences in specs of individual components tend to have a greater impact on performance as well.

[Paul Marossy]

I have never had a problem with any of the NTE parts that I have used. And I have used everything from JFETs to digital IC chips, they all worked just fine. I generally try to stay away from NTE stuff as they are just restamped parts from other manufacturers and are really expensive in comparison to the real thing most of the time, but sometimes I need stuff now and the only real local electronics store usually has the NTE part to do the job.

[compuwade]

I have never had a problem with any of the NTE parts that I have used. And I have used everything from JFETs to digital IC chips, they all worked just fine. I generally try to stay away from NTE stuff as they are just restamped parts from other manufacturers and are really expensive in comparison to the real thing most of the time, but sometimes I need stuff now and the only real local electronics store usually has the NTE part to do the job.

As I said, the devices worked, they just sounded like poo poo! I'm sure many of you have used NTE parts with no problems. But why bother when you 1, don't always know what you're getting, and 2, are going to pay $2 for a part that you can get for 15 cents or cheaper from mouser.

[Paul Marossy]

As I said, the devices worked, they just sounded like poo poo! I'm sure many of you have used NTE parts with no problems. But why bother when you 1, don't always know what you're getting, and 2, are going to pay $2 for a part that you can get for 15 cents or cheaper from mouser.

Why use NTE parts? If you need something today and the local electronics store has the NTE part right now vs. waiting a week or more to get your parts. It matters sometimes if you have a deadline to make or something along those lines. That's the point I was making. Otherwise I generally stay away from NTE stuff.

[FlyingZ]

I find NTE very poor quality and too wide on cross references. I will reluctantly used them as stated above.

[frank_p]

too wide on cross references.

I then don't understand why some stores relies on the NTE substitution chart to give you a part that have similar characteristics than the one with the code you need when not available, and that even if it's not a NTE relabeled.  I never compared the accuracy of substitutions lists but if NTE have so wide tolerances for the acceptance of a device under a code, what I understand is that the store using the list will accept bad reputation over an expanded number of categories...  OK, I get it, they will sell you something...  When you are hungry a donut, a muffin or a cookie is about the same.

[idiot savant]

I feel the need to post, the store I work for(not frys) deals almost exclusively with NTE.

The management is in love with the idea of tiny little blister pack parts, that you can hang on pegboard all nice in a row. Really, some of the parts themselves aren't so bad, but I've had entire lots(hundreds at a time) of germanium transistors come back out of spec. Similarly, today I just pulled several hundred 2w 270k 2% resistors for being out of spec by 15-20% no other values, -just- 270k. Just really random QC stuff all the time, and most of their datasheets are a joke.

The real sad aspect is the huge EDGE parts cartel the really controls which vendors the small brick & mortar stores can buy from. We could run a better, cheaper store ordering from mouser or digikey and marking things up a little. But, that's another can of worms...

[Mark Hammer]

I feel the need to post, the store I work for(not frys) deals almost exclusively with NTE.

The management is in love with the idea of tiny little blister pack parts, that you can hang on pegboard all nice in a row. Really, some of the parts themselves aren't so bad, but I've had entire lots(hundreds at a time) of germanium transistors come back out of spec. Similarly, today I just pulled several hundred 2w 270k 2% resistors for being out of spec by 15-20% no other values, -just- 270k. Just really random QC stuff all the time, and most of their datasheets are a joke.

The real sad aspect is the huge EDGE parts cartel the really controls which vendors the small brick & mortar stores can buy from. We could run a better, cheaper store ordering from mouser or digikey and marking things up a little. But, that's another can of worms...

Nice post.  I guess that when a company (like NTE) tries to be everything to everybody, it becomes harder to do a good job at it.

[MikeH]

My experience with NTE has been about 50/50.  I got some of their germs (big mistake) because they were cheap, and they were total crap.  On the other hand, one of my favorite ODs I've built actually has an NTE opamp in it.  But in general, I'd say avoid them.

[Paul Marossy]

I've used mostly NTE IC chips. They all worked perfectly. I am sure that transistors and FETs probably don't have a very good track record.

I've noticed on their cross reference that the same NTE part number covers a whole lot of different transistors. But I did need a specific FET for a FET preamp module I made for my Seymour Duncan Convertible amp, and a NTE part was the only way to get that FET. It worked just fine.

[MikeH]

That's a good point Paul; ICs inherently will be a lot more consistent than things like transistors and will probably almost always be fine from NTE.

And JFETs would be a definite no-no 

[petemoore]

  The Ge's were 'eh' sounding, and 3.98 per GE, a dozen tried, none in builds at the moment.
 The 458's were consistantly higher gain by a good bit than the next 'competitor' J201 or J202 in small batch of experiments, none in builds, also expensive, like the BCxxx in the respect of having a characteristic tone to them.
 Other than that the shop keeper guys are cool, they actually understand electronics and were able to help out here and there, keep a fairly huge inventory, right down the street...comes in handy.  

[compuwade]

I will admit, that even though I've had issues with NTE parts, it comes in handy to have a fry's down the street with a whole lot of usable parts.