STK 0039: Pretty sure I know the answer. . .

dbxdx5

Super Member
I need one STK 0039 module. Since all of the "new" pieces on evilbay are said to be Chinese fakes, the only real options appear to be either a used good one from a parts unit or ponying up for a pricey NOS. Correct?
 
You can use a chinese copy. I'd say 70% chance it will work OK, if not, buy another one from a different source. I've used chinese STKs for a while, I've found just one in 10 to be bad (oscillating, no way to correct it). Buying another one solved the problem. The modules are installed for several years now in different units, without issues (without abuse though, just home listening)

You can use a 0049, 0040 or 0050 too.
 
(oscillating, no way to correct it)

I have experienced this also with an STK module l bought from a local supplier which was obviously a chinese fake. It would run headphones but had bad distortion in both channels loaded with speakers. Had to throw the nice little Akai AM-2250 in the bin as it wasn't worth ordering another :(.

So maybe take a chance dbxdx5 but unfortunately it seems to be a bit of a roll of the dice when it comes to these modules. I did buy one off the bay about 2 years ago for a Sony that worked great. l did make sure l ordered one of the dearest listed that also looked as close as possible to the original.
 
Thanks. I may give the Chinese ones a shot, though I did find an NOS one locally for $40. :rolleyes:

I've seen STK 0039N a few places. Is that a sub for the non-N?
 
There is a thread in DIY here where they are using a discreet board made by an AK'r to sub for an STK device. Might be worth a look.
 
If you are not in a hurry, I can check my NOS stock from the 80-90's, they are not Chinese.

Thanks. I just bought one a half hour ago, but I've yet to install and test it. So in the event there's an issue with that one, it would be good to know if you have any.
 
This blanket statement that items originating from China are likely to be fakes falls into the category of Audiokarma "urban legend" to outright BS. I have in my hand a packing slip from Digikey with 10 line items of semiconductors. Nine of the ten originated from China and the other from Indonesia. Actually I don't remember anything I have purchased from DigiKey/Mouser in the last ten years that stated the country of origin was the USA, but plenty from Pakistan, Indonesia, Hong Kong, India, etc. I also know that IBM has China building their mid line servers for many years. I know there are fake/clones out there and one does have to be careful. I do tend to shy away from buying components on eBay but have been successful in getting good components that were not available elsewhere. I will not buy anything from Rumania though. Not that I got a bad component but I paid my money but did not get the component. I finally got my money back from eBay.

Anyone can get taken in on the internet marketplace. Several years ago Dell had an epidemic of mother board capacitors that were emitting magic smoke from counterfeit ones they got from somewhere. They would never say but if you called and said to the warranty folks your mother board (on a certain model) had gone belly up they would send a field service representative out to replace it next business day no questions asked. The service person would not give any info and took back the old motherboard. They would not let you keep it.

My rule of thumb when buying from Hong Kong/China is if the seller has sold thousands of items on eBay and is in good standing they are as safe a bet and buying from Digikey or Mouser. Some items are obviously clones but not always a fake. I bought a clone of a Hakko desoldering station because it was cheaper and it was. You do get what you pay for. Just my two cents.
 
Those STK hybrid amplifier modules have been out of production for over 20 years. Unless you get a real NOS one from B&D or the like, it's guaranteed to be a fake.
 
This blanket statement that items originating from China are likely to be fakes falls into the category of Audiokarma "urban legend" to outright BS. I have in my hand a packing slip from Digikey with 10 line items of semiconductors. Nine of the ten originated from China and the other from Indonesia. Actually I don't remember anything I have purchased from DigiKey/Mouser in the last ten years that stated the country of origin was the USA, but plenty from Pakistan, Indonesia, Hong Kong, India, etc. I also know that IBM has China building their mid line servers for many years. I know there are fake/clones out there and one does have to be careful. I do tend to shy away from buying components on eBay but have been successful in getting good components that were not available elsewhere. I will not buy anything from Rumania though. Not that I got a bad component but I paid my money but did not get the component. I finally got my money back from eBay.

Anyone can get taken in on the internet marketplace. Several years ago Dell had an epidemic of mother board capacitors that were emitting magic smoke from counterfeit ones they got from somewhere. They would never say but if you called and said to the warranty folks your mother board (on a certain model) had gone belly up they would send a field service representative out to replace it next business day no questions asked. The service person would not give any info and took back the old motherboard. They would not let you keep it.

My rule of thumb when buying from Hong Kong/China is if the seller has sold thousands of items on eBay and is in good standing they are as safe a bet and buying from Digikey or Mouser. Some items are obviously clones but not always a fake. I bought a clone of a Hakko desoldering station because it was cheaper and it was. You do get what you pay for. Just my two cents.

I don't know if you're addressing me, but I only said that the "new" STK 0039 modules being sold on ebay are said to be fakes made in China. As tarior noted above, the STK modules are obsolete. You can rant all you want about some larger perceived insult to or aggrievance against Chinese products, but it didn't come from me and it isn't the focus of MY thread: sourcing STK 0039 modules.
 
I think we could call them "fakes" , "copies", "new version", " replacement"... If a seller AD it as "original Sanyo" and send you a chinese copy, that's not OK, but if you buy a "replacement" STK, that's fine to me.
 
Here's the thing about the Chinese STK modules and other parts from China. The STKs are no longer used in current equipment so the manufacturer knows the market is limited to the service replacement parts. It is costly to set up a semiconductor production line so it is unlikely any reputable manufacturer is going to make them in quantity with quality equivalent to the original. The money just doesn't make sense. Therefore, if a company is going to make a good replacement it is going to be for the service market in limited quantities and will be expensive. There is no way to know for sure if what you are getting is good quality unless you know someone who has used it. I suggest that anyone who has found a reliable source for STK modules, and has tested them to rated power output with test equipment should post on AK so others will know.
BD Enterprises has found good suppliers for transistors and optical pickups that are no longer produced by the original manufacturers. It is safe to buy from them. We could start a thread for the STK modules to share info on good suppliers.
Best option is to use rcs16's new module!
 
Since all of the "new" pieces on evilbay are said to be Chinese fakes,
dbxdx5
Not particularly jumping to the defense of China but your statement in your first post is not really a statement of fact but an opinion based upon hearsay moved me to make that response to your statement.

I am aware the subject of the post is about STK0039. That is why I opened it.
 
dbxdx5
Not particularly jumping to the defense of China but your statement in your first post is not really a statement of fact but an opinion based upon hearsay moved me to make that response to your statement.

I am aware the subject of the post is about STK0039. That is why I opened it.

Right, and since this isn't a court room, hearsay IS admissable. ;)
 
Most semiconductors, and really everything else, is made in China now which wasn't being debated here. The reason the stuff coming from Mouser and Digikey (and the other reputable parts houses) is good is because it's from a known supplier chain and they take great pains to make sure what they are selling is the genuine article.

I don't know how it's urban myth when person after person blows up the eBay STKs with little or no load or hell, just on start up. Sure it might only be one in 10 that does this but I can guarantee that didn't happen when they were made by Sanyo.
Then you can move to the multitude of counterfeit transistor threads (not only on this site by a long shot) where there are tiny die stuck on whatever package in whatever number you can imagine, all on eBay right now. Oh, and the wonderful and infinite supply of NOS capacitors from whatever company you can name (even if that company never made them) that fail at half rated voltage.
Seriously, buying electronic parts on eBay is just silly at this point. Yes there are some reputable sellers on there but you really have to know who you're buying from because the vast majority are not. I suppose a good counterpoint to this is if you need a completely NLA module for your amp and aren't going to be surprised when the new part smokes on start up and you're ok with it.
 
I made the point earlier that anyone (Dell) can get burned. I buy from dealers of Pacific Rim only after I have done due diligence. I have a Hong Kong dealer on eBay with over 30K transactions and 97% 5 star performance. I read all of his negatives and not one alleged he sold counterfeit parts. I buy from this vendor with confidence. It all has to do with due diligence. This vendor does supply STK0039. I buy from Digikey and Mouser when the parts I need are available but sometimes eBay is a source that can supply a hard to get component. I would buy from a VAR from China than buy parts from some guy who stripped down a "working unit". The whole issue is "caveat emptor" [let the buyer beware]. Here is an important point for me on this issue is that blaming eBay because you got a bad part is "just silly". I wonder how many times a new good part that blew up because the real problem that caused the original failure was not resolved first was blamed on a fake part. Below is a cut/paste from Audiokarma member zenbulon1 on this issue.

"I don't completely subscribe to the counterfeit rumors. Many parts of the world retain their equipment and repair it when it fails. There is a demand for good repair parts to keep the non-disposable part of the world running. Equipment is expensive in third world country's, so repairing the stuff we deem junk they make profit in. The STK's we see here are made for that demand. The main things to watch out for in repairing the module driven sets is find a seller with history in selling the modules. Second make sure the amps driver stages are solid and fault free before installing any STK device. Third, prepare the module and heatsink for mounting by trimming back the plastic edge of the module allowing the metal back of the module to meet with the heatsink (This is Key) as any output transistor would. The modules get HOT! even when running at low/min volume. It is imperative to have good thermal contact to the heatsink. I've repaired many module driven sets and have only success with all of them. A few had driver stage issues that needed to be corrected others just modules. The counterfeit rap - "I believe, comes from novice repairs."
zebulon1 - May 24 2016

This is all I have to say on this issue.
 
If you buy an STK-0039 or 0050 (examples), and they were not manufactured by Sanyo, they are counterfeit. No ifs, ands, or buts. Sanyo was the only company to ever manufacture those specific part numbers.
Now, does that mean they won't work? Not necessarily. They may work, sound decent, and even hold up just fine.
However, you can bet money that they will not meet the specs of a Sanyo-made (or for other parts, their original manufacturer) part. Ever.

Out of necessity, I have used...we'll call them "aftermarket"... hybrid modules. They worked, and AFAIK, still work. The primary issue with the ones I had was deficient bias, and a tiny bit of crossover distortion at very low volume.

Zeb's advice holds true whether one has an "aftermarket" module or an original.
 
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