My mate over in New Zealand is a Service Tech, he wanted these parts for repairing equipment that belongs to customers.
He wasn't using them for his hobby, he was thinking of on-selling them to other people...
If he uses these parts, how does he know the part isn't going to fail in 6 months time and the customer returns the product for repair wanting it done for free as there is 1 year warranty on repairs!
Who has to pay for this - it comes out of his bottom line...
Potentially, if these parts were used for commercial purposes, then it could cost someone quite a lot of re-work and bad customer relations.
I think it is poor form to condone sloppy handling practices when it comes to ESD safe handling
You cannot just assume that everyone will use these parts for their "hobby", besides I take my hobby seriously and I would be really pissed off if I found out that bad ESD handling was the cause of my circuit failure.
I've invested in an ESD Antistatic Mat for my work bench with wrist strap etc etc - it didn't cost that much.
ESD Bag is best
Agree, this would have been better than nothing.
However, the ESD Bag with it's static dissipative properties are best. The open end of the bag must be folded over and closed, it cannot be left open though.
These things are cheap, even name brands like 3M, Statshield, Charles etc etc
Besides, the 2SK170 and other simialr TO-92 parts are mechanically pretty robust, especially when mounted on "Ammo Tape"; the Anti Stat Bag alone would probably be good enough for most shipping requirements
See: ESD Journal - ESD Bags for more info.
Agree, this would have been better than nothing.
However, the ESD Bag with it's static dissipative properties are best. The open end of the bag must be folded over and closed, it cannot be left open though.
These things are cheap, even name brands like 3M, Statshield, Charles etc etc
Besides, the 2SK170 and other simialr TO-92 parts are mechanically pretty robust, especially when mounted on "Ammo Tape"; the Anti Stat Bag alone would probably be good enough for most shipping requirements
See: ESD Journal - ESD Bags for more info.
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Lets agree to disagree on this one..
Personally, I don't think these parts are good enough for hobby use, having been handled without appropriate ESD safe practices etc.
Even for a hobby project, I want my phono stage, or amp etc, to work at its best: Irrespective of whether its for me, my friends or a bespoke project for someone else etc.
I think you might be selling yourself short to say they are fit for hobby use...FETs and MOSFETs are a different game compared to BJTs when it comes to ESD damage and post performance.
Personally, I don't think these parts are good enough for hobby use, having been handled without appropriate ESD safe practices etc.
Even for a hobby project, I want my phono stage, or amp etc, to work at its best: Irrespective of whether its for me, my friends or a bespoke project for someone else etc.
I think you might be selling yourself short to say they are fit for hobby use...FETs and MOSFETs are a different game compared to BJTs when it comes to ESD damage and post performance.
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if he as a repear company are buying parts outside of companys then he has only himself to blame if parts fail and he is the one stuck with the re-work billl.
What?
Are you saying you're happy to accept parts that, had a little bit more care been taken, could potentially work better in your project? But, rather settle for potentially inferior performance?
I wanted to buy some of these parts for my own use - if I do I'm playing Russian Roulette as to whether I get a good part or a bad part? Trouble is it might be 6 months or more before I figure it out, or hear the bad parts
TOSHIBA and other semiconductor manufacturers have pretty good quality assurance that means very high yields of top quality parts.
With Mr Fang not packaging his parts with appropriate ESD handling and packaging, then the TOSHIBA quality means nothing now.
Sorry, but in this case I cannot disagree with you more on this point.
If Mr Fang doesn't want to use ESD safe practices, then he could have advertised the fact on his EBAY auction site: "NO ESD HANDLING, all care but no responsibility!"
If you went and bought parts off this guy without realizing all this, don't take it out here, go back to Mr Fang...
Are you saying you're happy to accept parts that, had a little bit more care been taken, could potentially work better in your project? But, rather settle for potentially inferior performance?
I wanted to buy some of these parts for my own use - if I do I'm playing Russian Roulette as to whether I get a good part or a bad part? Trouble is it might be 6 months or more before I figure it out, or hear the bad parts
TOSHIBA and other semiconductor manufacturers have pretty good quality assurance that means very high yields of top quality parts.
With Mr Fang not packaging his parts with appropriate ESD handling and packaging, then the TOSHIBA quality means nothing now.
Sorry, but in this case I cannot disagree with you more on this point.
If Mr Fang doesn't want to use ESD safe practices, then he could have advertised the fact on his EBAY auction site: "NO ESD HANDLING, all care but no responsibility!"
If you went and bought parts off this guy without realizing all this, don't take it out here, go back to Mr Fang...
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i agree with the ESD issue. i did not coment on that issue.
but to use a service company, costomers, commercial use and such as a example on a forum for DIY hobby.
there is for a reason service company's buy there parts from vendors as farnell, RS +++. and not on ebay.
but to use a service company, costomers, commercial use and such as a example on a forum for DIY hobby.
there is for a reason service company's buy there parts from vendors as farnell, RS +++. and not on ebay.
I can see where you're coming from and that's fair enough. But this site isn't just about DIY, there are a lot of commercial manufacturers/professionals using this forum, just have a look at some of the posts in the Solid State section...
Sometimes when parts go bad you can't always pinpoint the cause unless there has been some testing, and that can be exhaustive, both in time and cost.
Whether it's commercial, a DIY project or bespoke one-off for a friend - should it matter? I think not - it's just splitting hairs otherwise
I'm told that 9 times of 10, the customer will never work it out that the repairs in the first place used faulty parts. The customer just pays again to get it fixed.
So in the end the real loser, in this case, is almost always the customer/consumer/end-user.
For me and a couple of other mates from the local Audio Club, we where going to go ahead an order a whole lot of 2SK170s from Mr Fang for a Phono Head Amp design, that each of us were going to build for ourselves.
There's no way I'm going to buy these parts now as I have no idea of the quality, and I'm not going to wait 6 months or more to test these parts...to see if they are actually damaged.
The problem with a lot ESD damage situations, is that it is a partial destruction of the silicon junction on the die, to see the damage, you actually need to look at the silicon under an electron microscope - bugger that.
My intention to put up this information was two fold:
1. Draw people's attention to the fact that it appears Mr Fang doesn't take any ESD safe handling and packaging precautions
2. Perhaps Mr Fang will get the idea that it might be a good idea an go and invest in an ESD Antistatic Mat, Wrist strap and Anti-stat bags and start handling and packaging these parts in manner that they should be
That way we all benefit, reducing the likelihood of receiving parts that screw-up projects and have you wasting your time trying to figure why things aren't working the way they should
At the prices Mr Fang is charging for these parts, given what they cost 12 months ago, I think it is a small ask for Mr Fang to use ESD safe handling and packaging.
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I have bought over a thousand jfets and fets from Zhou fang over the past 3 years and not had a bad one. I have used thousands of Toshiba jfets for 25 years, sorted them by IDSS in plastic parts drawers and think I've had 2 bad ones in the past ten years . The obsession here with ESD packing is greatly overblown.
Given the questionable Chinese /Hong Kong vendors Zhou Fang making these available for the past few years has been a real help for DIYers. Sure they've gone up as the supply as ceased from Toshiba, did you stock up when they were less?
Given the questionable Chinese /Hong Kong vendors Zhou Fang making these available for the past few years has been a real help for DIYers. Sure they've gone up as the supply as ceased from Toshiba, did you stock up when they were less?
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I have a question about ESD safety.
Doesn't grounding the legs together in paper eliminate the danger during transit?
If the jfets are in paper tape, so the die, plastic case, legs and tape are all at the same potential, does static danger still exist?
If removed from the packaging on a safe mat I would think all would be fine.
Dave
Doesn't grounding the legs together in paper eliminate the danger during transit?
If the jfets are in paper tape, so the die, plastic case, legs and tape are all at the same potential, does static danger still exist?
If removed from the packaging on a safe mat I would think all would be fine.
Dave
Another $100 donated.
I do not have time to account for the the donation due.
After this $100, I will do another $100 next year, this should cove my previous donation promise.
Total donation to date $350
Sales on this this forum is still suspended, as I have no time to handle it.
Some items are available on my E-bay account.
I do not have time to account for the the donation due.
After this $100, I will do another $100 next year, this should cove my previous donation promise.
Total donation to date $350
Sales on this this forum is still suspended, as I have no time to handle it.
Some items are available on my E-bay account.
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Does anyone know Zhoufang's ebay identity? I tried searching for "Zhoufang" and came up empty.
Regards,
Scott
Regards,
Scott
That would be nice as his private message mailbox is too full to send a message.
I live in vietnam. I want to buy are 2x(Toshiba 2SK170-BL / BL 2SJ74-matched) and 4x(SiC JFET Semisouth SJEP120R100). How to buy?
Zhou fang's jfets
Hi,
Try this seller - he now owns the stock
http://www.diyaudio.com/forums/vend...uding-some-very-rare-toshiba-transistors.html
Steve.
Hi,
Try this seller - he now owns the stock
http://www.diyaudio.com/forums/vend...uding-some-very-rare-toshiba-transistors.html
Steve.
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